Heart² - Developer Guide

By: Team Heart² Since: Aug 2018 Last updated: November 2018 Licence: MIT

1. Introduction

Welcome to Heart²! Heart² is a desktop software intended to make the job of wedding planning agencies simpler. It provides simple yet powerful features to efficiently manage clients' and agency companies' profiles. Users can find suitable vendors providing wedding services for couples using just a few keystrokes with our enterprise feature set.

This developer guide is a self-contained resource designed to align all developers around a common vision. It helps developers of all levels learn more about the workings behind the scenes and how to make use of them effectively.

So if you want to know how to make Heart² even better, here’s where you start!

Callouts are rectangular boxes with an icon and words to point out some information. Below are 3 callouts that will be used throughout this document:

ℹ️	This represents a note. A note indicates additional important information. Be sure to read these notes as they might be applicable to you!

💡	This represents a tip. A tip denotes something that is often handy, and good for you to know. Tips are often less crucial, and you can choose to skip them.

⚠️	This represents a warning. A warning denotes something of crucial importance, and you should be extremely cautious when reading the statement.

What's in this Developer Guide:

1. Introduction
2. Setting Up
3. Design
4. Implementation
5. Documentation
6. Testing
7. Dev Ops
Appendix A: Suggested Programming Tasks to Get Started
- A.1. Improving each component
- A.2. Creating a new command: remark
Appendix B: Product Scope
Appendix C: User Stories
Appendix D: Use Cases
Appendix E: Non Functional Requirements
Appendix F: Glossary
Appendix G: Instructions for Manual Testing

2. Setting Up

This section provides information on setting up your local computer and importing all the necessary tools required to run this application.

⚠️	Read this section in detail and follow the configurations carefully. Otherwise, the application may not work as expected.

2.1. Prerequisites

JDK 9 or later

⚠️
JDK 10 on Windows will fail to run tests in headless mode due to a JavaFX bug. Windows developers are highly recommended to use JDK 9.
IntelliJ IDE

ℹ️
IntelliJ by default has Gradle and JavaFx plugins installed.
Do not disable them. If you have disabled them, go to File > Settings > Plugins to re-enable them.

2.2. Setting up the project in your computer

Fork this repo, and clone the fork to your computer
Open IntelliJ (if you are not in the welcome screen, click File > Close Project to close the existing project dialog first)
Set up the correct JDK version for Gradle
1. Click Configure > Project Defaults > Project Structure
2. Click New… and find the directory of the JDK
Click Import Project
Locate the build.gradle file and select it. Click OK
Click Open as Project
Click OK to accept the default settings
Open a console and run the command gradlew processResources (Mac/Linux: ./gradlew processResources). It should finish with the BUILD SUCCESSFUL message.
This will generate all resources required by the application and tests.
Open XmlAdaptedPerson.java and MainWindow.java and check for any code errors
1. Due to an ongoing issue with some of the newer versions of IntelliJ, code errors may be detected even if the project can be built and run successfully
2. To resolve this, place your cursor over any of the code section highlighted in red. Press ALT+ENTER, and select Add '--add-modules=…' to module compiler options for each error
Repeat this for the test folder as well (e.g. check XmlUtilTest.java and HelpWindowTest.java for code errors, and if so, resolve it the same way)

2.3. Verifying the setup

Run the seedu.address.MainApp and try a few commands
Run the tests to ensure they all pass.

2.4. Configurations to do before writing code

2.4.1. Configuring the coding style

This project follows oss-generic coding standards. IntelliJ’s default style is mostly compliant with ours but it uses a different import order from ours. To rectify,

Go to File > Settings… (Windows/Linux), or IntelliJ IDEA > Preferences… (macOS)
Select Editor > Code Style > Java
Click on the Imports tab to set the order
- For Class count to use import with '*' and Names count to use static import with '*': Set to 999 to prevent IntelliJ from contracting the import statements
- For Import Layout: The order is import static all other imports, import java.*, import javax.*, import org.*, import com.*, import all other imports. Add a <blank line> between each import

Optionally, you can follow the UsingCheckstyle.adoc document to configure Intellij to check style-compliance as you write code.

2.4.2. Updating documentation to match your fork

After forking the repo, the documentation will still have the SE-EDU branding and refer to the se-edu/addressbook-level4 repo.

If you plan to develop this fork as a separate product (i.e. instead of contributing to se-edu/addressbook-level4), you should do the following:

Configure the site-wide documentation settings in build.gradle, such as the site-name, to suit your own project.
Replace the URL in the attribute repoURL in DeveloperGuide.adoc and UserGuide.adoc with the URL of your fork.

2.4.3. Setting up CI

Set up Travis to perform Continuous Integration (CI) for your fork. See UsingTravis.adoc to learn how to set it up.

After setting up Travis, you can optionally set up coverage reporting for your team fork (see UsingCoveralls.adoc).

ℹ️	Coverage reporting could be useful for a team repository that hosts the final version but it is not that useful for your personal fork.

Optionally, you can set up AppVeyor as a second CI (see UsingAppVeyor.adoc).

ℹ️	Having both Travis and AppVeyor ensures your App works on both Unix-based platforms and Windows-based platforms (Travis is Unix-based and AppVeyor is Windows-based)

2.4.4. Getting started with coding

When you are ready to start coding,

Get some sense of the overall design by reading Section 3.1, “Architecture”.
Take a look at Appendix A, Suggested Programming Tasks to Get Started.

3. Design

This section shows an overview of the design decisions for this application. It serves to allow you to better understand the various components linking this application together.

3.1. Architecture

Figure 1. Architecture Diagram

The Architecture Diagram given above explains the high-level design of the App. Given below is a quick overview of each component.

💡	The `.pptx` files used to create diagrams in this document can be found in the diagrams folder. To update a diagram, modify the diagram in the pptx file, select the objects of the diagram, and choose `Save as picture`.

Main has only one class called MainApp. It is responsible for,

At app launch: Initializes the components in the correct sequence, and connects them up with each other.
At shut down: Shuts down the components and invokes cleanup method where necessary.

Commons represents a collection of classes used by multiple other components. Two of those classes play important roles at the architecture level.

EventsCenter : This class (written using Google’s Event Bus library) is used by components to communicate with other components using events (i.e. a form of Event Driven design)
LogsCenter : Used by many classes to write log messages to the App’s log file.

The rest of the App consists of four components.

UI: The UI of the App.
Logic: The command executor.
Model: Holds the data of the App in-memory.
Storage: Reads data from, and writes data to, the hard disk.

Each of the four components

Defines its API in an interface with the same name as the Component.
Exposes its functionality using a {Component Name}Manager class.

For example, the Logic component (see the class diagram given below) defines it’s API in the Logic.java interface and exposes its functionality using the LogicManager.java class.

Figure 2. Class Diagram of the Logic Component

Events-Driven nature of the design

The Sequence Diagram below shows how the components interact for the scenario where the user issues the command client#1 delete.

Figure 3. Component interactions for `client#1 delete ` command (part 1)

ℹ️	Note how the `Model` simply raises a `AddressBookChangedEvent` when the Address Book data are changed, instead of asking the `Storage` to save the updates to the hard disk.

The diagram below shows how the EventsCenter reacts to that event, which eventually results in the updates being saved to the hard disk and the status bar of the UI being updated to reflect the 'Last Updated' time.

Figure 4. Component interactions for client#1 delete command (part 2)

ℹ️	Note how the event is propagated through the `EventsCenter` to the `Storage` and `UI` without `Model` having to be coupled to either of them. This is an example of how this Event Driven approach helps us reduce direct coupling between components.

The sections below give more details of each component.

3.2. UI component

Figure 5. Structure of the UI Component

API : Ui.java

The UI consists of a MainWindow. The MainWindow is made up of parts e.g.CommandBox, ResultDisplay, PersonListPanel, StatusBarFooter, BrowserPanel etc. All these, including the MainWindow, inherit from the abstract UiPart class.

The UI component uses JavaFx UI framework. The layout of these UI parts are defined in matching .fxml files that are in the src/main/resources/view folder. For example, the layout of the MainWindow is specified in MainWindow.fxml

The UI component,

Executes user commands using the Logic component.
Binds itself to some data in the Model so that the UI can auto-update when data in the Model change.
Responds to events raised from various parts of the App and updates the UI accordingly.

3.3. Logic component

Figure 6. Structure of the Logic Component

API : Logic.java

Logic uses the AddressBookParser class to parse the user command.
This results in a Command object which is executed by the LogicManager.
The command execution can affect the Model (e.g. adding a person) and/or raise events.
The result of the command execution is encapsulated as a CommandResult object which is passed back to the Ui.

Given below is the Sequence Diagram for interactions within the Logic component for the execute("client#1 delete") API call.

Figure 7. Interactions Inside the Logic Component for the client#1 delete Command

3.4. Model component

Figure 8. Structure of the Model Component

API : Model.java

The Model,

stores a UserPref object that represents the user’s preferences.
stores the Address Book data.
stores the Account data that was used to log in.
exposes an unmodifiable ObservableList<Person> that can be 'observed' e.g. the UI can be bound to this list so that the UI automatically updates when the data in the list change.
does not depend on any of the other three components.

ℹ️	As a more OOP model, we can store a `Tag` list in `Address Book`, which `Person` can reference. This would allow `Address Book` to only require one `Tag` object per unique `Tag`, instead of each `Person` needing their own `Tag` object. An example of how such a model may look like is given below.

3.5. Storage component

Figure 9. Structure of the Storage Component

API : Storage.java

The Storage component,

can save UserPref objects in json format and read it back.
can save the Address Book data in xml format and read it back.

3.6. Account Storage component

Figure 10. Structure of the Account Storage Component

API : AccountStorage.java

The AccountStorage component

can save the Account data in xml format and read it back.
can populate a default root Account data in xml format if missing.
can update existing Account password stored in the storage.

3.7. Common classes

Classes used by multiple components are in the seedu.addressbook.commons package.

4. Implementation

Before you start, you’d need to find out how Heart²'s features work! This section describes some noteworthy details on how certain features are implemented.

4.1. Undo/Redo feature

4.1.1. Current Implementation

The undo/redo mechanism is facilitated by VersionedAddressBook. It extends AddressBook with an undo/redo history, stored internally as an addressBookStateList and currentStatePointer. Additionally, it implements the following operations:

VersionedAddressBook#commit() — Saves the current address book state in its history.
VersionedAddressBook#undo() — Restores the previous address book state from its history.
VersionedAddressBook#redo() — Restores a previously undone address book state from its history.

These operations are exposed in the Model interface as Model#commitAddressBook(), Model#undoAddressBook() and Model#redoAddressBook() respectively.

Given below is an example usage scenario and how the undo/redo mechanism behaves at each step.

Step 1. The user launches the application for the first time. The VersionedAddressBook will be initialized with the initial address book state, and the currentStatePointer pointing to that single address book state.

Step 2. The user executes delete 5 command to delete the 5th person in the address book. The delete command calls Model#commitAddressBook(), causing the modified state of the address book after the delete 5 command executes to be saved in the addressBookStateList, and the currentStatePointer is shifted to the newly inserted address book state.

Step 3. The user executes add n/David … to add a new person. The add command also calls Model#commitAddressBook(), causing another modified address book state to be saved into the addressBookStateList.

ℹ️	If a command fails its execution, it will not call `Model#commitAddressBook()`, so the address book state will not be saved into the `addressBookStateList`.

Step 4. The user now decides that adding the person was a mistake, and decides to undo that action by executing the undo command. The undo command will call Model#undoAddressBook(), which will shift the currentStatePointer once to the left, pointing it to the previous address book state, and restores the address book to that state.

ℹ️

If the currentStatePointer is at index 0, pointing to the initial address book state, then there are no previous address book states to restore. The undo command uses Model#canUndoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the undo.

The following sequence diagram shows how the undo operation works:

The redo command does the opposite — it calls Model#redoAddressBook(), which shifts the currentStatePointer once to the right, pointing to the previously undone state, and restores the address book to that state.

ℹ️

If the currentStatePointer is at index addressBookStateList.size() - 1, pointing to the latest address book state, then there are no undone address book states to restore. The redo command uses Model#canRedoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the redo.

Step 5. The user then decides to execute the command list. Commands that do not modify the address book, such as list, will usually not call Model#commitAddressBook(), Model#undoAddressBook() or Model#redoAddressBook(). Thus, the addressBookStateList remains unchanged.

Step 6. The user executes clear, which calls Model#commitAddressBook(). Since the currentStatePointer is not pointing at the end of the addressBookStateList, all address book states after the currentStatePointer will be purged. We designed it this way because it no longer makes sense to redo the add n/David … command. This is the behavior that most modern desktop applications follow.

The following activity diagram summarizes what happens when a user executes a new command:

4.1.2. Design Considerations

Aspect: How undo & redo executes

Alternative 1 (current choice): Saves the entire address book.
- Pros: Easy to implement.
- Cons: May have performance issues in terms of memory usage.
Alternative 2: Individual command knows how to undo/redo by itself.
- Pros: Will use less memory (e.g. for delete, just save the person being deleted).
- Cons: We must ensure that the implementation of each individual command are correct.

Aspect: Data structure to support the undo/redo commands

Alternative 1 (current choice): Use a list to store the history of address book states.
- Pros: Easy for new Computer Science student undergraduates to understand, who are likely to be the new incoming developers of our project.
- Cons: Logic is duplicated twice. For example, when a new command is executed, we must remember to update both HistoryManager and VersionedAddressBook.
Alternative 2: Use HistoryManager for undo/redo
- Pros: We do not need to maintain a separate list, and just reuse what is already in the codebase.
- Cons: Requires dealing with commands that have already been undone: We must remember to skip these commands. Violates Single Responsibility Principle and Separation of Concerns as HistoryManager now needs to do two different things.

Aspect: What it shows after undo/redo command successfully executes

Alternative 1 (current choice): Shows the list that was changed due to the undo/redo command.
- Pros: Easy for the user to identify what was changed, whether a client or vendor was modified.
- Cons: It switches the list out of the current filter and the user have to re-type the list command if he wants to filter the list.
Alternative 2: Keeps showing what was shown before the command was executed.
- Pros: Easy to implement.
- Cons: Hard for the user to identify what was changed in the addressbook.
Alternative 3: Show what was changed, before and after.
- Pros: User can easily tell what was changed.
- Cons: Hard to implement, need to have an additional UI components to show what was changed and need additional components to store the list before it was changed.

4.2. Logging

We are using java.util.logging package for logging. The LogsCenter class is used to manage the logging levels and logging destinations.

The logging level can be controlled using the logLevel setting in the configuration file (See Section 4.3, “Configuration”)
The Logger for a class can be obtained using LogsCenter.getLogger(Class) which will log messages according to the specified logging level
Currently log messages are output through: Console and to a .log file.

Logging Levels

SEVERE : Critical problem detected which may possibly cause the termination of the application
WARNING : Can continue, but with caution
INFO : Information showing the noteworthy actions by the App
FINE : Details that is not usually noteworthy but may be useful in debugging e.g. print the actual list instead of just its size

4.3. Configuration

Certain properties of the application can be controlled (e.g App name, logging level) through the configuration file (default: config.json).

4.4. Login Feature

Before the user can use Heart², they must first log in with a registered account.

4.4.1. Before logging in

The user is presented with a login UI:

Figure 11. The login screen when user launches the application.

There are only 3 commands available for user to execute:

login : Login to the system with a username and password
help : Show the help panel
exit : Quit the application

4.4.2. After logging in

The LoginWindow is hidden and the MainWindow is shown upon successful login.

The user can execute all available commands, if the user-account is given the correct privilege. However, the user cannot execute the login command again since he is already logged in.

4.4.3. Design Considerations

Aspect: How to show the Login UI

Alternative 1 (current choice): Deploy the LoginWindow upon launch by parsing a new loginStage each time.
- Pros: Similar to existing applications, easier for users to use. Hides all MainWindow details.
- Cons: Creation of a new loginStage may result in performance issues.
Alternative 2: Deploy the LoginWindow as a modal window above the MainWindow.
- Pros: Easy to implement.
- Cons: Users are able to see the MainWindow before login. Requires the hiding and showing of inner parts in the MainWindow which may result in performance issues.

4.5. Account creation

An account is created for the purpose of logging in and authenticating the user, before the user is allowed to use the application. This protects the confidentiality and data integrity of the application.

ℹ️

The user can only register for an account via an existing account with SUPER_USER privilege. It may sound counter-intuitive to require an account before registering a new account. We make this requirement as only authorised personal should be given an account. Ideally, the owner of the application should dictate the account given to employees by helping them register an account.

4.5.1. Types of account

There are 2 types of accounts:

SUPER_USER : A user that is capable of executing all commands available in the application.
READ_ONLY_USER : A user that is capable of executing all commands except registering new account, adding, editing, and deleting entries in the database.

These 2 types of accounts are referred as Role and facilitated by the Role enum.

The restrictions of a READ_ONLY_USER is enforced by the methods found in Account class, specifically:

boolean hasWritePrivilege()
boolean hasDeletePrivilege()
boolean hasAccountCreationPrivilege()

Commands that prevents a READ_ONLY_USER from executing is checked with a condition as such:

if (!account.hasWritePrivilege()) {
    throw new LackOfPrivilegeException(COMMAND_WORD);
}

4.5.2. Design Considerations

Aspect: Should the privilege be tied to Role enum or Account class?

Alternative 1 (current choice): Account class contains the privileges methods such has hasWritePrivilege.
- Pros: This makes sense as the type of privilege is tied to the account.
Alternative 2: Role enum should contains the privileges methods
- Pros: Since Role enum contains all the different roles such as READ_ONLY_USER and SUPER_USER, it is easy to reference all the different types of roles and the privileges in 1 file. This makes adding more roles and privileges in the future easy.
- Cons: It sounds awkward to have privileges associated with Role rather than with an Account.

Aspect: What type of access control to use?

Alternative 1 (current choice): Role based access control. (RBAC)
- Pros: Most relevant in the context of this application. Allows application owner to set privileges for employees.
- Cons: User does not have a say in access control, even in content created by them.
Alternative 2: Discretionary Access Control (DAC)
- Pros: Less restrictive. Allows individual complete control over content they have created.
- Cons: Not really applicable in our context as we want to restrict employee access to data. Employee’s access control based on their individual roles in the company seems more appropriate than employees having access based on the content they create.

4.6. Account storage

All accounts are stored in a file call /data/accountlist.xml. This file is generated on the fly during first launch and populated with a root account. By default, a root account is hardcoded into the application with the username rootUser and password rootPassword with the role SUPER_USER.

The diagram below shows what happens when a user launches the application:

Figure 12. Activity diagram when user launches the application

Only a SUPER_USER is allowed to create a new account, either for himself, or on behalf of another person. The diagram below shows what happen when a user attempts to register a new account:

Figure 13. Activity diagram when user registers an account

To change the default root account, navigate to the static method getRootAccount() in Account.java:

public static Account getRootAccount() {
    return new Account("rootUser", "rootPassword", Role.SUPER_USER);
}

Change the rootUser, rootPassword, and Role.SUPER_USER accordingly to your needs. It is necessary to have a default root account, otherwise no account will exist and one cannot execute the register account command without first logging in.

⚠️	It is advisable to assign `SUPER_USER` as the root account. Otherwise, you are not able to register any other account without first logging in to a `SUPER_USER` account.

4.6.1. Design Considerations

Aspect: What file type to store user account as?

Alternative 1 (current choice): Store it as a xml file locally.
- Pros: The code to write and read xml file is already present for adding address book contact initially in the Address Book - level 4 app. Hence, adopting this code and modifying it for account storage is easier than coming up with code from scratch.
- Cons: Relatively wordy and verbose with all the opening and closing tag. For the same amount of account information, compared to other format such as json, more data has to be stored to account for tag elements.
Alternative 2: Store it as a json file locally.
- Pros: Simpler syntax than xml and hence less data is required to store the same amount of account information.
- Pros: Can be parsed into a ready-to-use JavaScript object.
- Cons: Not familiar with json, hence more effort is needed to write code to store account in json format, compared to the already given code for xml storage.

4.6.2. Security Considerations

Database

Currently, the list of accounts is stored locally on data/accountlist.xml. For security purposes, we may consider the following implementations in the future for v2.0:

Encrypt accountlist.xml: This can prevent direct lookup of the file as the content is encrypted
Store the file on a server: Due to project restriction, we are unable to implement this at v1.4. Storing file on a server has an added advantage of utilising web security practises or employing third party services to help protect our account list in private servers.

Storing password

Username is stored in plaintext in accountlist.xml, as username is not private information. However, user password is hashed with PBKDF2WithHmacSHA512 algorithm together with a salt, to prevent password from being visible in plaintext. PBKDF2WithHmacSHA512 is deliberately chosen as it is a slower algorithm, thus slowing down brute-force attack for finding out user password. The hashing algorithm is present in PasswordAuthentication class and the implementation is based off this stackoverflow answer.

4.7. Unique ID feature

Heart² assigns a unique ID to every client and vendor when they are added into Heart². This ID is unique within their contact type, meaning that a client and a vendor may have the same ID, but since this ID comes hand in hand with the contact type, they are effectively unique. These IDs are last for a single session, and Heart² reassigns the IDs at the start of the next session.

4.7.1. Current Implementation

Both the Client and Vendor class have a public static running counter starting from 1. When a client or vendor is created, it is assigned that number, before incrementing it by 1. The contact then has this ID for this session, and the user can use this ID, coupled with the contact type to always refer to this particular contact.

This unique ID is used by many other commands, namely: add, delete, update, view, addservice, automatch. It allows for these commands to be executed at any point in Heart², with always the same context.

4.7.2. Design Considerations

Aspect: How should we refer to contacts in Heart²?

Alternative 1: Use the legacy implementation, which is to use the relative position of the contact in the list.
- Pros: No change is required, as it is the legacy implementation.
- Cons: Users have to navigate to a list that shows that contact, and the relative position of that contact may keep changing throughout a session.
Alternative 2 (current choice):
- Pros: Users are able to refer back to a particular contact at any time, without requiring the current list shown to contain that contact. Also, this ID will never change during a session, so the user can confidently use the ID knowing that it will always refer to that contact.
- Cons: Users still have to remember this unique ID to refer back to the contact. It might be hard to remember the ID.

After much consideration, we decided to go with option 2. Heart² is built for speed, and we would like to give our users flexibility to execute any command within Heart² at any time. We believe that this can give users more control and power over their work using Heart², and therefore we chose to implement this unique ID system.

However, we also do realise that users might find it hard to remember the unique ID assigned to the contact. While users can quickly look at a recent contact using the command history, a possibly quality-of-life improvement would be to implement a mnemonic unique identifier.

4.8. Add contact feature

Heart² requires users to explicitly specify whether the contact to be added is a client or a vendor in the command.

client add n/Wai Lun p/90463327 e/wailun@u.nus.edu a/PGP House
vendor add n/Lun Wai p/72336409 e/lunwai@u.nus.edu a/RVRC

The above commands add a client and a vendor, together with the details provided, respectively.

This differentiation between client and vendor facilitates many other features of Heart². It complements the unique ID feature earlier to ensure that a client and a vendor with the same ID are still differentiable due to the contact type.

Adding of duplicate contacts are not allowed in Heart².

ℹ️	A contact is considered a duplicate if they are of the same contact type and have the same name and have either the same phone number or email address.

4.8.1. Current Implementation

Both Client and Vendor classes inherit from an abstract Contact class. When adding a contact, either a new Client or a Vendor object is instantiated. Both Client and Vendor objects are added to a list of generic type Contact.

In order to differentiate them, there is an abstract method Contact#getType() that Client and Vendor implement differently. Client objects return a ContactType.CLIENT enum while Vendor objects return a ContactType.VENDOR enum.

When adding a contact, the parser first distinguishes whether it is an addition of a client or vendor. The correct ContactType enum is then passed to AddCommandParser. The AddCommandParser parses the argument to create the appropriate contact, and creates the appropriate AddCommand.

This AddCommand is passed back to the LogicManager, and the method execute() is called. The contact is then added to the model.

Below is the sequence diagram of a client add command.

4.8.2. Design Considerations

Aspect: How should we store `Client` and `Vendor` objects in Heart²?

Alternative 1 (current choice): Client and Vendor objects are stored in a more general Contact list.
- Pros: Easy to implement by tweak the inherited legacy list slightly.
- Cons: Cannot tell immediately if an element in the Contact list is a Client or Vendor. This might take a longer time to display lists, due to having to filter them every time.
Alternative 2: Hold Client and Vendor objects differently in two different lists.
- Pros: Able to get Client or Vendor immediately without having to go through the entire Contact list as in alternative 1.
- Cons: Difficult and extremely tedious to implement.

Aspect: How restrictive should the definition of a duplicate contact be?

Alternative 1: It should be regardless of contact type, meaning a client and a vendor cannot have the same name and either the same phone number or email.
- Pros: No additional implementation required. The legacy implementation already supports this.
- Cons: Less flexibility for our users. A client cannot be a vendor possibly.
Alternative 2 (current choice): A client and a vendor can have similar fields, meaining a client and a vendor can possibly have the same name, phone number and/or email.
- Pros: More flexibility for our users. A client can be a vendor too, which is possible in the real world.
- Cons: Additional implementation to have.

4.9. Delete contact feature

Heart² allows the user to delete any contact, using the combination of its contact type and its unique ID, followed by delete.

client#2 delete
vendor#3 delete

The above commands delete the client given the unique ID #2 and the vendor given the unique ID #3.

This feature makes use of the fact that contacts are either Client or Vendor objects. The unique ID is then used to identify the particular Client or Vendor object to be deleted.

4.9.1. Current Implementation

The current implementation filters the contact list by the specified contact type and ID. The predicate to filter by client and vendor can be retrieved by ContactType.CLIENT#getFilter() and ContactType.VENDOR#getFilter() respectively. This first predicate is then combined with another predicate that is looking for the ID of the client or vendor, specified in the command.

Since IDs are unique, after filtering by this (combined) predicate, the list can only have a maximum length of 1. This would indicate that the contact in the list is the contact we are to delete. However, if the list is of size 0, this means that the contact that is specified to be deleted does not exist. We then can feedback to the user that the ID specified is invalid.

💡	The sequence diagram for the `delete` command can be found together with the structure of the logic component here.

4.10. Update contact feature

Heart² allows the user to update any contact, using the combination of its contact type and its unique ID, followed by update.

'client#1 update n/Wai Lua'
'vendor#2 update p/9046 3328'

The above commands update the name of the client given the unique ID #2 to "Wai Lua", and the phone number of the vendor given the unique ID #2 to 9046 3328.

ℹ️	A contact is considered a duplicate if they are of the same contact type and have the same name and have either the same phone number or email address.

As mentioned earlier, duplicate contacts are not allowed in Heart². Thus, when updating, the user is not allowed to update a contact in Heart² if updating it will result in duplicated contacts.

4.10.1. Implementation

The current implementation uses part of the legacy implementation to do the updating of contacts. The arguments are parsed and tokenized using ArgumentTokenizer#tokenize(String, Prefix…). An EditContactDescriptor object is then created to hold this new information temporarily.

💡	The prefixes applicable to `update` are `n/`, `p/`, `e/`, `a/`, `t/`. At least one of them must follow the `update` command.

Then, the current implementation filters the contact list by the specified contact type and ID. The predicate to filter by client and vendor can be retrieved by ContactType.CLIENT#getFilter() and ContactType.VENDOR#getFilter() respectively. This first predicate is then combined with another predicate that is looking for the ID of the client or vendor, specified in the command.

Since IDs are unique, after filtering by this (combined) predicate, the list can only have a maximum length of 1. The contact in this list would be the contact to be updated. A new contact is created using UpdateCommand#createEditedContact(Contact, EditContactDescriptor, ContactType). The next step is then to ensure that this new contact is not a duplicate contact, before replacing the old contact in Heart².

ℹ️	A contact is considered a duplicate if they are of the same contact type and have the same name and have either the same phone number or email address.

However, if the list is of size 0, this means that the contact that is specified to be deleted does not exist. We then can feedback to the user that the ID specified is invalid.

4.10.2. Design Considerations

Aspect: Should a similar (have the same name and same phone number or email) `client` and `vendor` object be updated together?

Alternative 1 (current choice): A client can be similar to a vendor, but they are still considered independent contacts in Heart².
- Pros: No implementation required. The user has the choice to have their client and vendor be similar or not be.
- Cons: There are scenarios where the user would like to update the details of both the client and vendor together as they are similar. In this case, they will have to update both manually.
Alternative 2: Updating a similar client or vendor should update its counterpart.
- Pros: The user can update a similar client and vendor together.
- Cons: Hard to implement. Also, the user will lack the flexibility of having his client and vendor be updated individually.

After much consideration, we decided to choose option 1, so that our user can have more flexibility in Heart². A lot of people have separate phone numbers and emails for personal use and work, and thus it made sense to us that these contacts should still be updated separately.

However, there will definitely be cases where users might want such similar contacts to be linked and updated together. A possible quality-of-life improvement would be to allow an option (command) to link such similar contacts to each other, for updating.

4.11. View contact feature

Heart² allows the user to view any contact, using the combination of its contact type and its unique ID, followed by view.

client#3 view
vendor#6 view

The above commands selects the client with the unique ID #3 and the vendor with the unique ID #6 respectively for viewing. The contact’s card is shown on the panel on the right in Heart², containing all the information regarding the contact.

💡	By using `view`, all the information regarding the contact will be shown. This includes the name, phone number, email address, tags, residential (`client`) or office address (`vendor`), and services requested (`client`) or services offered (`vendor`).

4.11.1. Implementation

The view command uses a similar implementation to the add, delete and update commands. The current implementation filters the contact list by the specified contact type and ID. The predicate to filter by client and vendor can be retrieved by ContactType.CLIENT#getFilter() and ContactType.VENDOR#getFilter() respectively. This first predicate is then combined with another predicate that is looking for the ID of the client or vendor, specified in the command.

Since IDs are unique, after filtering by this (combined) predicate, the list can only have a maximum length of 1. After obtaining this contact, a new JumpToListRequestEvent is posted to the event bus. The PersonListPanel class is registered as an event handler, and it handles this JumpToListRequestEvent with PersonListPanel#handleJumpToListRequestEvent(JumpToListRequestEvent). The contact’s card is then selected for viewing.

However, if the list is of size 0, this means that the contact that is specified for viewing does not exist. We then can feedback to the user that the ID specified is invalid.

4.11.2. Design Considerations

The implementation of view was chosen to also use the combination of the contact type and ID to select a contact for viewing. This is part of a standardisation effort to have cohesiveness in the command syntax.

4.12. Adding a service request feature

Heart² allows the user to add attributes of the services the user’s clients require or vendors can provide. They can be indicated using the addservice command, by their unique IDs:

client#123 addservice s/photographer c/1000.00
vendor#123 addservice s/photographer c/1000.00

4.12.1. Implementation

Given below is a sequence diagram of how the addservice operation works:

Figure 14. Add Service Command Sequence Diagram

The command is first parsed into the AddServiceCommandParser, which breaks up the arguments into their respective fields. A new Service is created and parsed into the AddServiceCommand along with the ID.

Only when there is no existing request of that service type that the specified service request can be added with AddServiceCommand#createContactWithService(). All fields of the Contact including the existing services would be copied over to a new Contact with the EditContactDescriptor in UpdateCommand. Next, the new service would be added with EditCommandDescriptor#addservice().

The contact would be updated with Model#updateContact() and later saved into the AddressBook storage.

4.12.2. Design Considerations

Aspect 1: Cost storage

Alternative 1 (current choice): Store with BigDecimal.
- Pros: More precise representation, crucial to sensitive data like money.
- Cons: Difficult to retrieve value for display and parsing.
Alternative 2: Store with Double.
- Pros: Easier to retrieve value for display and parsing.
- Cons: Less precise representation, may lose accuracy.

Aspect 2: Updating of Service request

Alternative 1 (current choice): No updating allowed. Each request type can only be entered once.
- Pros: Easy to implement.
- Cons: Users who made a mistake while updating would have to delete and add the entire contact to the database.
Alternative 2: Update with the same addservice command.
- Pros: Users can still update without much hassle.
- Cons: Users might accidentally overwrite the wrong data.
Alternative 3: Update with the update command.
- Pros: Users can update with less possibility of overwriting the wrong data.
- Cons: Difficult to implement. UpdateCommand would have too many command variations. In addition, both the service cost and type has to be stated in the command.

4.13. Automatch feature

4.13.1. Implementation

4.13.2. Search Result Display

After the user enters the automatch command into the CommandBox, individual ServiceListPanel s would be deployed to list the search results in a tabular form:

Figure 15. Automatch Table View

Profile

The enquired contact’s profile would be displayed on the right, so as to facilitate the user in picking the vendors or clients while keeping the requirements in mind. The contact’s data is extracted from Contact#getUrlContactData() and the text is set at their respective placeholders.

Tabular View

The results would be listed from the most to the least relevant based on the enquired contact’s price requests. Users can then scroll through the list to view the other results in decreasing relevancy.

Design Considerations

Aspect: How to display search results

Alternative 1 (current choice): Present in a table
- Pros: Provides a bird’s-eye view of all plausible vendors for the enquired client or clients for the enquired vendor so that the user can pick the combination that best suits the client or vendor easily
- Cons: May have performance issues in terms of the extraction of data
Alternative 2: Present in a list
- Pros: More efficient performance
- Cons: Users need to scroll through the list for each contact individually without knowing which service category the contact falls under.

4.14. List Feature

Heart² allows you view all the clients or the vendors with a simple command: list.

When listing contacts, you would have to specify whether the contact is a client or a vendor by prefixing it to list:

client list
vendor list

Below shows an example of how listing all clients works:

Figure 16. The UI showing how to list all clients.

Furthermore, you are also able to add keywords after the list to do filtering, and each keyword is specified to belong to a category and only contacts which contains all of the keywords in their respective categories will be shown.

ℹ️	Categories include: `n/ NAME` `p/ PHONE_NUMBER` `e/ EMAIL_ADDRESS` `a/ ADDRESS` `t/ TAGS`

Below shows an example of how list filtering works:

Figure 17. The UI showing list filtering.

4.14.1. Implementation

The keywords from the command to be used for filtering is parsed by the ListCommandParser into a ContactInformation and passed to a Predicate to be used for filtering. The Predicate is implemented as ContactContainsKeywordsPredicate.

Below is a sequence diagram showing the creation of the ListCommand.

Figure 18. The Sequence Diagram of the creation of a list command.

We use a FilteredList and pass the combination of 2 Predicates into it, one to filter the type of contact, clients or vendors and the other is to filter by keywords, which is the ContactContainsKeywordsPredicate from the ListCommandParser.

Below is a sequence diagram showing the execution of the ListCommand.

Figure 19. The Sequence Diagram of the execution of a list command.

4.14.2. Design considerations

Aspect 1: Substring Matching or Word Matching

Alternative 1 (current choice): Substring matching.
- Pros: Users would be able to view a wider range of results that matches the substring they have given. Easier to use.
- Cons: Irrelevant results might not be filtered away if they contain the substring.
Alternative 2: Word matching.
- Pros: Guarantees that no irrelevant results are shown.
- Cons: Relevant results that have a small difference in the wording will be filtered away and not shown.

Aspect 2: Categorised or Non-categorised keywords

Alternative 1 (current choice): Categorised keywords.
- Pros: Users are able to specify which keywords they want to search for in which category. Gives better control over the searching.
- Cons: Users have to follow a specific format to type the keywords.
Alternative 2: Non-categorised keywords.
- Pros: User can type in the keywords in any order they want. Easier to use.
- Cons: Irrelevant results that contains the keywords will be shown.

Aspect 3: All Match or Any Match

Alternative 1 (current choice): All match.
- Pros: Users can specify what they want to search for and filter out all irrelevant results.
- Cons: Users are not able to search for multiple things, when they only require one of them to match.
Alternative 2: Any match.
- Pros: Users are able to obtain a wider search result. Easier to use.
- Cons: Irrelevant results that contains only one or a few keywords will be shown as well.

4.15. Finding matches between clients and vendors

The application boasts matchmaking features that reduces the (once-laborious) task of matching vendors a single command.

4.15.1. High level design

Figure 20. High level overview of how auto-matching works

On invocation, the auto-matchmaking algorithm functionally maps all service requirements from a Client into predicates for performing the first step of filtering the Vendors.
The vendors are then sorted by a fair ranking algorithm to ensure even distribution of jobs between Vendors.

4.15.2. Design considerations

Aspect: How to fairly distribute jobs between vendors

Alternative 1 (current choice): Pure random matching
- Pros: Fair at every selection round, easy implementation
- Cons: Even job distribution not guaranteed
Alternative 2: Round robin
- Pros: Even job distribution guaranteed
- Cons: Requires keeping count of jobs allocated for each vendor
Alternative 3: Review/ranking-based distribution
- Pros: Fair and rewards good performance
- Cons: Difficult to fine-tune ranking algorithm

5. Documentation

We use asciidoc for writing documentation.

ℹ️	We chose asciidoc over Markdown because asciidoc, although a bit more complex than Markdown, provides more flexibility in formatting.

5.1. Editing Documentation

See UsingGradle.adoc to learn how to render .adoc files locally to preview the end result of your edits. Alternatively, you can download the AsciiDoc plugin for IntelliJ, which allows you to preview the changes you have made to your .adoc files in real-time.

5.2. Publishing Documentation

See UsingTravis.adoc to learn how to deploy GitHub Pages using Travis.

5.3. Converting Documentation to PDF format

We use Google Chrome for converting documentation to PDF format, as Chrome’s PDF engine preserves hyperlinks used in webpages.

Here are the steps to convert the project documentation files to PDF format.

Follow the instructions in UsingGradle.adoc to convert the AsciiDoc files in the docs/ directory to HTML format.
Go to your generated HTML files in the build/docs folder, right click on them and select Open with → Google Chrome.
Within Chrome, click on the Print option in Chrome’s menu.
Set the destination to Save as PDF, then click Save to save a copy of the file in PDF format. For best results, use the settings indicated in the screenshot below.

Figure 21. Saving documentation as PDF files in Chrome

5.4. Site-wide Documentation Settings

The build.gradle file specifies some project-specific asciidoc attributes which affects how all documentation files within this project are rendered.

💡	Attributes left unset in the `build.gradle` file will use their default value, if any.

Table 1. List of site-wide attributes

Attribute name	Description	Default value
`site-name`	The name of the website. If set, the name will be displayed near the top of the page.	not set
`site-githuburl`	URL to the site’s repository on GitHub. Setting this will add a "View on GitHub" link in the navigation bar.	not set
`site-seedu`	Define this attribute if the project is an official SE-EDU project. This will render the SE-EDU navigation bar at the top of the page, and add some SE-EDU-specific navigation items.	not set

5.5. Per-file Documentation Settings

Each .adoc file may also specify some file-specific asciidoc attributes which affects how the file is rendered.

Asciidoctor’s built-in attributes may be specified and used as well.

💡	Attributes left unset in `.adoc` files will use their default value, if any.

Table 2. List of per-file attributes, excluding Asciidoctor’s built-in attributes

Attribute name	Description	Default value
`site-section`	Site section that the document belongs to. This will cause the associated item in the navigation bar to be highlighted. One of: `UserGuide`, `DeveloperGuide`, `LearningOutcomes`, `AboutUs`, `ContactUs` Official SE-EDU projects only	not set
`no-site-header`	Set this attribute to remove the site navigation bar.	not set

5.6. Site Template

The files in docs/stylesheets are the CSS stylesheets of the site. You can modify them to change some properties of the site’s design.

The files in docs/templates controls the rendering of .adoc files into HTML5. These template files are written in a mixture of Ruby and Slim.

⚠️

Modifying the template files in docs/templates requires some knowledge and experience with Ruby and Asciidoctor’s API. You should only modify them if you need greater control over the site’s layout than what stylesheets can provide. The SE-EDU team does not provide support for modified template files.

6. Testing

Tests ensure that your code runs as expected. This section shows how you can run tests to test this application thoroughly.

6.1. Running Tests

There are three ways to run tests.

💡	The most reliable way to run tests is the 3rd one. The first two methods might fail some GUI tests due to platform/resolution-specific idiosyncrasies.

Method 1: Using IntelliJ JUnit test runner

To run all tests, right-click on the src/test/java folder and choose Run 'All Tests'
To run a subset of tests, you can right-click on a test package, test class, or a test and choose Run 'ABC'

Method 2: Using Gradle

Open a console and run the command gradlew clean allTests (Mac/Linux: ./gradlew clean allTests)

ℹ️	See UsingGradle.adoc for more info on how to run tests using Gradle.

Method 3: Using Gradle (headless)

Thanks to the TestFX library we use, our GUI tests can be run in the headless mode. In the headless mode, GUI tests do not show up on the screen. That means the developer can do other things on the Computer while the tests are running.

To run tests in headless mode, open a console and run the command gradlew clean headless allTests (Mac/Linux: ./gradlew clean headless allTests)

6.2. Types of tests

We have two types of tests:

GUI Tests - These are tests involving the GUI. They include,
1. System Tests that test the entire App by simulating user actions on the GUI. These are in the systemtests package.
2. Unit tests that test the individual components. These are in seedu.address.ui package.
Non-GUI Tests - These are tests not involving the GUI. They include,
1. Unit tests targeting the lowest level methods/classes.
  e.g. seedu.address.commons.StringUtilTest
2. Integration tests that are checking the integration of multiple code units (those code units are assumed to be working).
  e.g. seedu.address.storage.StorageManagerTest
3. Hybrids of unit and integration tests. These test are checking multiple code units as well as how the are connected together.
  e.g. seedu.address.logic.LogicManagerTest

6.3. Troubleshooting Testing

Problem: HelpWindowTest fails with a NullPointerException.

Reason: One of its dependencies, HelpWindow.html in src/main/resources/docs is missing.
Solution: Execute Gradle task processResources.

7. Dev Ops

DevOps is an approach to include automation and event monitoring at all steps of the software build. This section documents the tools and methods we used to ensure a high quality code production.

7.1. Build Automation

See UsingGradle.adoc to learn how to use Gradle for build automation.

7.2. Continuous Integration

We use Travis CI and AppVeyor to perform Continuous Integration on our projects. See UsingTravis.adoc and UsingAppVeyor.adoc for more details.

7.3. Coverage Reporting

We use Coveralls to track the code coverage of our projects. See UsingCoveralls.adoc for more details.

7.4. Documentation Previews

When a pull request has changes to asciidoc files, you can use Netlify to see a preview of how the HTML version of those asciidoc files will look like when the pull request is merged. See UsingNetlify.adoc for more details.

7.5. Making a Release

Here are the steps to create a new release.

Update the version number in MainApp.java.
Generate a JAR file using Gradle.
Tag the repo with the version number. e.g. v0.1
Create a new release using GitHub and upload the JAR file you created.

7.6. Managing Dependencies

A project often depends on third-party libraries. For example, Address Book depends on the Jackson library for XML parsing. Managing these dependencies can be automated using Gradle. For example, Gradle can download the dependencies automatically, which is better than these alternatives.
a. Include those libraries in the repo (this bloats the repo size)
b. Require developers to download those libraries manually (this creates extra work for developers)

Appendix A: Suggested Programming Tasks to Get Started

Suggested path for new programmers:

First, add small local-impact (i.e. the impact of the change does not go beyond the component) enhancements to one component at a time. Some suggestions are given in Section A.1, “Improving each component”.
Next, add a feature that touches multiple components to learn how to implement an end-to-end feature across all components. Section A.2, “Creating a new command: remark” explains how to go about adding such a feature.

A.1. Improving each component

Each individual exercise in this section is component-based (i.e. you would not need to modify the other components to get it to work).

`Logic` component

Scenario: You are in charge of logic. During dog-fooding, your team realize that it is troublesome for the user to type the whole command in order to execute a command. Your team devise some strategies to help cut down the amount of typing necessary, and one of the suggestions was to implement aliases for the command words. Your job is to implement such aliases.

💡	Do take a look at Section 3.3, “Logic component” before attempting to modify the `Logic` component.

Add a shorthand equivalent alias for each of the individual commands. For example, besides typing clear, the user can also type c to remove all persons in the list.
- Hints
  
  Just like we store each individual command word constant COMMAND_WORD inside *Command.java (e.g. FindCommand#COMMAND_WORD, DeleteCommand#COMMAND_WORD), you need a new constant for aliases as well (e.g. FindCommand#COMMAND_ALIAS).
  
  AddressBookParser is responsible for analyzing command words.
- Solution
  
  Modify the switch statement in AddressBookParser#parseCommand(String) such that both the proper command word and alias can be used to execute the same intended command.
  
  Add new tests for each of the aliases that you have added.
  
  Update the user guide to document the new aliases.
  
  See this PR for the full solution.

`Model` component

Scenario: You are in charge of model. One day, the logic-in-charge approaches you for help. He wants to implement a command such that the user is able to remove a particular tag from everyone in the address book, but the model API does not support such a functionality at the moment. Your job is to implement an API method, so that your teammate can use your API to implement his command.

💡	Do take a look at Section 3.4, “Model component” before attempting to modify the `Model` component.

Add a removeTag(Tag) method. The specified tag will be removed from everyone in the address book.
- Hints
  
  The Model and the AddressBook API need to be updated.
  
  Think about how you can use SLAP to design the method. Where should we place the main logic of deleting tags?
  
  Find out which of the existing API methods in AddressBook and Person classes can be used to implement the tag removal logic. AddressBook allows you to update a person, and Person allows you to update the tags.
- Solution
  
  Implement a removeTag(Tag) method in AddressBook. Loop through each person, and remove the tag from each person.
  
  Add a new API method deleteTag(Tag) in ModelManager. Your ModelManager should call AddressBook#removeTag(Tag).
  
  Add new tests for each of the new public methods that you have added.
  
  See this PR for the full solution.

`Ui` component

Scenario: You are in charge of ui. During a beta testing session, your team is observing how the users use your address book application. You realize that one of the users occasionally tries to delete non-existent tags from a contact, because the tags all look the same visually, and the user got confused. Another user made a typing mistake in his command, but did not realize he had done so because the error message wasn’t prominent enough. A third user keeps scrolling down the list, because he keeps forgetting the index of the last person in the list. Your job is to implement improvements to the UI to solve all these problems.

💡	Do take a look at Section 3.2, “UI component” before attempting to modify the `UI` component.

Use different colors for different tags inside person cards. For example, friends tags can be all in brown, and colleagues tags can be all in yellow.

Before

After
- Hints
  
  The tag labels are created inside the PersonCard constructor (new Label(tag.tagName)). JavaFX’s Label class allows you to modify the style of each Label, such as changing its color.
  
  Use the .css attribute -fx-background-color to add a color.
  
  You may wish to modify DarkTheme.css to include some pre-defined colors using css, especially if you have experience with web-based css.
- Solution
  
  You can modify the existing test methods for PersonCard 's to include testing the tag’s color as well.
  
  See this PR for the full solution.
  
  The PR uses the hash code of the tag names to generate a color. This is deliberately designed to ensure consistent colors each time the application runs. You may wish to expand on this design to include additional features, such as allowing users to set their own tag colors, and directly saving the colors to storage, so that tags retain their colors even if the hash code algorithm changes.
Modify NewResultAvailableEvent such that ResultDisplay can show a different style on error (currently it shows the same regardless of errors).

Before

After
- Hints
  
  NewResultAvailableEvent is raised by CommandBox which also knows whether the result is a success or failure, and is caught by ResultDisplay which is where we want to change the style to.
  
  Refer to CommandBox for an example on how to display an error.
- Solution
  
  Modify NewResultAvailableEvent 's constructor so that users of the event can indicate whether an error has occurred.
  
  Modify ResultDisplay#handleNewResultAvailableEvent(NewResultAvailableEvent) to react to this event appropriately.
  
  You can write two different kinds of tests to ensure that the functionality works:
  
  The unit tests for ResultDisplay can be modified to include verification of the color.
  
  The system tests AddressBookSystemTest#assertCommandBoxShowsDefaultStyle() and AddressBookSystemTest#assertCommandBoxShowsErrorStyle() to include verification for ResultDisplay as well.
  
  See this PR for the full solution.
  
  Do read the commits one at a time if you feel overwhelmed.
Modify the StatusBarFooter to show the total number of people in the address book.

Before

After
- Hints
  
  StatusBarFooter.fxml will need a new StatusBar. Be sure to set the GridPane.columnIndex properly for each StatusBar to avoid misalignment!
  
  StatusBarFooter needs to initialize the status bar on application start, and to update it accordingly whenever the address book is updated.
- Solution
  
  Modify the constructor of StatusBarFooter to take in the number of persons when the application just started.
  
  Use StatusBarFooter#handleAddressBookChangedEvent(AddressBookChangedEvent) to update the number of persons whenever there are new changes to the addressbook.
  
  For tests, modify StatusBarFooterHandle by adding a state-saving functionality for the total number of people status, just like what we did for save location and sync status.
  
  For system tests, modify AddressBookSystemTest to also verify the new total number of persons status bar.
  
  See this PR for the full solution.

`Storage` component

Scenario: You are in charge of storage. For your next project milestone, your team plans to implement a new feature of saving the address book to the cloud. However, the current implementation of the application constantly saves the address book after the execution of each command, which is not ideal if the user is working on limited internet connection. Your team decided that the application should instead save the changes to a temporary local backup file first, and only upload to the cloud after the user closes the application. Your job is to implement a backup API for the address book storage.

💡	Do take a look at Section 3.5, “Storage component” before attempting to modify the `Storage` component.

Add a new method backupAddressBook(ReadOnlyAddressBook), so that the address book can be saved in a fixed temporary location.
- Hint
  
  Add the API method in AddressBookStorage interface.
  
  Implement the logic in StorageManager and XmlAddressBookStorage class.
- Solution
  
  See this PR for the full solution.

A.2. Creating a new command: `remark`

By creating this command, you will get a chance to learn how to implement a feature end-to-end, touching all major components of the app.

Scenario: You are a software maintainer for addressbook, as the former developer team has moved on to new projects. The current users of your application have a list of new feature requests that they hope the software will eventually have. The most popular request is to allow adding additional comments/notes about a particular contact, by providing a flexible remark field for each contact, rather than relying on tags alone. After designing the specification for the remark command, you are convinced that this feature is worth implementing. Your job is to implement the remark command.

A.2.1. Description

Edits the remark for a person specified in the INDEX.
Format: remark INDEX r/[REMARK]

Examples:

remark 1 r/Likes to drink coffee.
Edits the remark for the first person to Likes to drink coffee.
remark 1 r/
Removes the remark for the first person.

A.2.2. Step-by-step Instructions

[Step 1] Logic: Teach the app to accept 'remark' which does nothing

Let’s start by teaching the application how to parse a remark command. We will add the logic of remark later.

Main:

Add a RemarkCommand that extends Command. Upon execution, it should just throw an Exception.
Modify AddressBookParser to accept a RemarkCommand.

Tests:

Add RemarkCommandTest that tests that execute() throws an Exception.
Add new test method to AddressBookParserTest, which tests that typing "remark" returns an instance of RemarkCommand.

[Step 2] Logic: Teach the app to accept 'remark' arguments

Let’s teach the application to parse arguments that our remark command will accept. E.g. 1 r/Likes to drink coffee.

Main:

Modify RemarkCommand to take in an Index and String and print those two parameters as the error message.
Add RemarkCommandParser that knows how to parse two arguments, one index and one with prefix 'r/'.
Modify AddressBookParser to use the newly implemented RemarkCommandParser.

Tests:

Modify RemarkCommandTest to test the RemarkCommand#equals() method.
Add RemarkCommandParserTest that tests different boundary values for RemarkCommandParser.
Modify AddressBookParserTest to test that the correct command is generated according to the user input.

[Step 3] Ui: Add a placeholder for remark in `PersonCard`

Let’s add a placeholder on all our PersonCard s to display a remark for each person later.

Main:

Add a Label with any random text inside PersonListCard.fxml.
Add FXML annotation in PersonCard to tie the variable to the actual label.

Tests:

Modify PersonCardHandle so that future tests can read the contents of the remark label.

[Step 4] Model: Add `Remark` class

We have to properly encapsulate the remark in our Person class. Instead of just using a String, let’s follow the conventional class structure that the codebase already uses by adding a Remark class.

Main:

Add Remark to model component (you can copy from Address, remove the regex and change the names accordingly).
Modify RemarkCommand to now take in a Remark instead of a String.

Tests:

Add test for Remark, to test the Remark#equals() method.

[Step 5] Model: Modify `Person` to support a `Remark` field

Now we have the Remark class, we need to actually use it inside Person.

Main:

Add getRemark() in Person.
You may assume that the user will not be able to use the add and edit commands to modify the remarks field (i.e. the person will be created without a remark).
Modify SampleDataUtil to add remarks for the sample data (delete your addressBook.xml so that the application will load the sample data when you launch it.)

[Step 6] Storage: Add `Remark` field to `XmlAdaptedPerson` class

We now have Remark s for Person s, but they will be gone when we exit the application. Let’s modify XmlAdaptedPerson to include a Remark field so that it will be saved.

Main:

Add a new Xml field for Remark.

Tests:

Fix invalidAndValidPersonAddressBook.xml, typicalPersonsAddressBook.xml, validAddressBook.xml etc., such that the XML tests will not fail due to a missing <remark> element.

[Step 6b] Test: Add withRemark() for `PersonBuilder`

Since Person can now have a Remark, we should add a helper method to PersonBuilder, so that users are able to create remarks when building a Person.

Tests:

Add a new method withRemark() for PersonBuilder. This method will create a new Remark for the person that it is currently building.
Try and use the method on any sample Person in TypicalPersons.

[Step 7] Ui: Connect `Remark` field to `PersonCard`

Our remark label in PersonCard is still a placeholder. Let’s bring it to life by binding it with the actual remark field.

Main:

Modify PersonCard's constructor to bind the Remark field to the Person 's remark.

Tests:

Modify GuiTestAssert#assertCardDisplaysPerson(…) so that it will compare the now-functioning remark label.

[Step 8] Logic: Implement `RemarkCommand#execute()` logic

We now have everything set up… but we still can’t modify the remarks. Let’s finish it up by adding in actual logic for our remark command.

Main:

Replace the logic in RemarkCommand#execute() (that currently just throws an Exception), with the actual logic to modify the remarks of a person.

Tests:

Update RemarkCommandTest to test that the execute() logic works.

A.2.3. Full Solution

See this PR for the step-by-step solution.

Appendix B: Product Scope

Target user profile:

has a need to plan for events (weddings)
has a need to manage a significant number of contacts
has a need to link contacts together
prefer desktop apps over other types
can type fast
prefers typing over mouse input
is reasonably comfortable using CLI apps

Value proposition: simplify the process of wedding management for the user, his clients and vendors

Appendix C: User Stories

Priorities: High (must have) - * * *, Medium (nice to have) - * *, Low (unlikely to have) - *

Priority	As a …	I want to …	So that I can…
`* * *`	on-task project manager	add new clients with the type of services they request for	get the required vendors for the event accordingly
`* * *`	thoughtful project manager	add new vendors with the type of services they can offer and their costs	match the vendors to the clients accordingly
`* * *`	efficient project manager	search the database for the vendor that best suits the requirements based on filters	find the most suitable vendor for my clients
`* * *`	goal-driven project manager	be able to set individual checkpoints and reminders for the many components that a project may have	have a clearer picture on the progress of all the different projects
`* * *`	flexible project manager	update the database of vendors’ data	have an up-to-date database that accurately reflects my vendors
`* * *`	busy project manager	easily see all unserviced clients	I can quickly complete assigning vendors to them
`* * *`	organised project manager	view the availability of my vendors	I will not assign vendors to clients when they are unavailable
`* * *`	responsible project head	provide authentication for the project managers and staff	our clients’ and vendors’ data are only accessible by those who has access to them
`* * *`	organised project manager	be able to archive previous projects in a separate location	they would not clutter my workspace but would still be available for review in the future
`* *`	organised project manager	access clients and vendors separately	I can look through their data more efficiently
`* *`	modular project manager	offer packages to clients	clients with no particular preferences can be attended to efficiently
`*`	efficient project manager	create templates	I can easily serve customers of similar request types
`*`	customer-first project manager	have a ratings and feedback system given by clients for the vendors	I can sieve out the better vendors for future clients
`*`	profit-motivated marketing head	calculate the rough estimate of the cost of each project	source for vendors that would maximise my profits

Appendix D: Use Cases

(For all use cases below, the System is the Heart² application, and the Actor is the user, unless specified otherwise)

D.1. Use case: Add Client/Vendor

Preconditions: User is logged in with a SUPER_USER account.

MSS

User requests to add a new Client/Vendor
System adds the new Client/Vendor into the database

Use case ends.

Extensions

1a. The new Client/Vendor’s syntax is not entered correct.
- 1a1. System shows a feedback to the user that the Client/Vendor was not entered correctly.
  
  Use case ends.

D.2. Use case: Update Client/Vendor

Preconditions: User is logged in with a SUPER_USER account.

MSS

User requests to update an existing Client/Vendor
System updates the existing Client/Vendor according to the User’s requests

Use case ends.

Extensions

1a. The Client/Vendor does not exist.
- 1a1. System shows a feedback to the user that the Client/Vendor does not exist.
  
  Use case ends.

D.3. Use case: Delete Client/Vendor

Preconditions: User is logged in with a SUPER_USER account.

MSS

User requests to delete an existing Client/Vendor
System deletes the Client/Vendor specified

Use case ends.

Extensions

1a. The Client/Vendor does not exist.
- 1a1. System shows a feedback to the user that the Client/Vendor does not exist
  
  Use case ends.

D.4. Use case: Login

Preconditions: User is logged out.

MSS

User requests to log in with his username and password
System validates the information entered and allows the user access to the System
User is successfully logged in

Use case ends.

Extensions

1a. User enters an incorrect username
- 1a1. The system display an error message and prompts the user to re-enter his username
- Use case resumes from step 1.

1b. User enters an incorrect password
- 1b1. The system will request the user to re-enter his password
- 1b2. The user attempts to enter his password
  - 1b2.1 The system determines that the password is incorrect and provides the option for user to retrieve his forgotten password
- Steps 1b1 and 1b2 are repeated until the user enters his correct password
- Use case resumes from step 3.

D.5. Use case: Logout

Preconditions: User is logged in.

MSS

User requests to logout from the System
System logs User out
User is successfully logged out

Use case ends.

D.6. Use case: Register an account

Preconditions: User is logged in with a SUPER_USER account.

MSS

User requests to register a new account
System validates the information entered and register the new account
User has successfully register a new account

Use case ends.

Extensions

1a. User is not a SUPER_USER.
- 1a1. System rejects the command to register a new account and feedback to the user that he is not a SUPER_USER.
  
  Use case ends.
1b. User types in an invalid username.
- 1b1. System prompts the User the correct format of the command that can be used.
  
  Use case ends.
1c. User types in an invalid password.
- 1c1. System prompts the User the correct format of the password that can be used.
  
  Use case ends.
1d. User types in a username that already exists.
- 1d1. System prompts the User that the username has been taken and suggest the User to choose another username.
  
  Use case ends.

D.7. Use case: Changing an existing account password

Preconditions: User is logged in.

MSS

User requests to change the password of his account
System validates the information entered and change the user password.
User’s password is successfully updated.

Use case ends.

Extensions

1a. User’s old password is typed in wrongly.
- 1a1. System rejects the command to change the user’s password and feedback to the user that his old password was typed in wrongly.
  
  Use case ends.

1b. User new password is invalid format.
- 1a1. System prompts the user that his password is not a valid password and proceed to tell the user whether he has entered an empty password or a password with space.
  
  Use case ends.

D.8. Use case: List all the Clients or Vendors

Preconditions: User is logged in with a SUPER_USER account.

MSS

User enters the list command and requests to view either all the Clients, or all the Vendors.
System returns either a list with all the Clients' information, or all the Vendors' information.

Use case ends.

Extensions

2a. There is no Client or no Vendor available
- 2a1. System returns an empty list.
Use case ends.

D.9. Use case: Filter and show Client’s or Vendor’s info according to the filter

Preconditions: User is logged in with a SUPER_USER account.

MSS

User enters the list command and requests to view either Client’s or Vendor’s information with some keywords provided indicated by prefixes.
The System displays a list of Clients or Vendors whose information matches what was provided.

Use case ends.

Extensions

1a. User enters a prefix that does not exist.
- 1a1. System prompts the User the correct format of the command and prefixes that can be used.
1b. User enters an empty prefix.
- 1b1. System prompts the User the correct format of the command and prefixes that can be used.
Use case ends.

D.10. Use Case: Adding a new service request

Preconditions: User is logged in with a SUPER_USER account.

Guarantees:

Service would be added to the specified contact only if the command is successful.
The new service addition will not wipe out the previous service additions.

MSS

User enters the add service command with the specified client or vendor, along with the service type and price.
System adds the service to the contact and displays the result of the command in the result display.

Use case ends.

Extensions

1a. System detects an invalid ID.
- 1a1. System prompts User that the ID is invalid.
- Use case ends.
1b. System detects an invalid service type.
- 1b1. System prompts User with the available service types.
- Use case ends.
1c. System detects an invalid service cost.
- 1c1. System prompts User with the cost format requirements.
- Use case ends.

D.11. Use case: Match the most suitable Vendor to a Client’s needs

Preconditions: User is logged in with a SUPER_USER account.

MSS

User attempts to match a Client’s need to an available Vendor
System matches a Vendor that it deemed the most suitable to the Client

Use case ends.

Extensions

1a. The Client has no need. That is to say, the Client is not looking for any Vendor
- 1a1. System recognises that the Client has no need, and return a message to feedback to the User
  
  Use case ends.
2a. There is no Vendor available that matches the Client’s need
- 2a1. System feedback to the User that no Vendor is available for the current Client’s need
  
  Use case ends.

Appendix E: Non Functional Requirements

E.1. Availability

Application should work on any mainstream OS as long as it has Java 9 or higher installed.
Application should only be available for Wedding Managers with login credentials
Application should be available 24hrs everyday without down time
Data stored into the Application should be available to Users without corruption

E.2. Performance

Application should be able to hold up to 1000 Clients and 1000 Vendors without a noticeable sluggishness in performance for typical usage.

E.3. Usability

Application should be intuitive and easy to use for users after following the User Guide
A user with above average typing speed for regular English text (i.e. not code, not system admin commands) should be able to accomplish most of the tasks faster using commands than using the mouse.
A user without any technical knowledge should be able to use the program efficiently with the help of the user guide.

E.4. Reliability

Application should be able to match Vendor to Client’s needs correctly.
Application should be able to perform all the commands without fail.

E.5. Scalability

Application should be able to scale automatically even after reaching 1000 Clients or 1000 Vendors.
Huge number of Clients and Vendors’s data may cause some waiting time for commands to process, but Application should still be able to execute all the commands without fail.

E.6. Data Integrity

Only authorized Users with specific login credentials should be able to add, update, or delete data directly from the Application.
All monetary amounts should be accurate to 2 decimal places.

Appendix F: Glossary

Mainstream OS: Windows, Linux, Unix, OS-X
Private contact detail: A contact detail that is not meant to be shared with others
Client: The Client is the primary receiver and the party that requires the services of the Project Manager and Vendors. The Client puts up requests to the Project Manager to handle their wedding event.
Vendor: The Vendors are what the Project Manager needs to connect his Clients to, to fulfil the Clients' needs and wants. Vendors provide goods and services required for the clients’ weddings and they depend on the Project Manager to look for suitable Clients.
Project Manager: The User of the application; the Project Manager of a wedding planning company that needs to engage his Clients with his Vendors, managing a large amount of wedding requests at a time.
Event: A single request related to the wedding that the Client expects. The Project Manager plans for and provide this request from a Vendor. The event encapsulates many different services, such as: wedding photography, formal wedding attire rental, banquet catering, invitation printing, and many others.

Appendix G: Instructions for Manual Testing

Given below are instructions to test the app manually.

ℹ️

These instructions only provide a starting point for testers to work on; testers are expected to do more exploratory testing. For all commands except for login, help, and exit, user is expected to have already logged in to the application successfully and be at the main screen GUI page, not the login GUI page.

ℹ️	For all `add`, `update`, `delete`, `clear`, and `register account` commands, the account that executes it must be a `SUPER_USER` account.

G.1. Launch the application

Initial launch
1. Download the jar file and copy into an empty folder
2. Double-click the jar file
  Expected: Shows the login page GUI. The window size may not be optimum.
Saving window preferences
1. Resize the window to an optimum size. Move the window to a different location. Close the window.
2. Re-launch the app by double-clicking the jar file.
  Expected: The most recent window size and location is retained.

G.2. Shutdown the application

Exit the application with a command
1. Test case: exit
  Expected: The GUI screen closes and the application exits.
Exit the application by clicking on the GUI close button or force quitting the app (e.g. alt + f4 on Windows, and cmd + q on Mac)
1. Expected: The GUI screen closes and the application exits.

G.3. Adding a contact

Adding a contact in Heart²
1. Test case: <CONTACT_TYPE> add n/Test user e/test@example.com a/test address p/11111111 t/test
  Expected: The contact is added to either the client or vendor list, depending on the contact type specified in the command. Timestamp in the status bar is updated.
2. Test case: <CONTACT_TYPE> add n/Test two user e/test a/test address 2 p/22222222 t/test
  Expected: No contact is added. Error details are shown in the status message. Status bar remains the same.
3. Other incorrect add commands to try: commands missing required fields, adding a duplicate contact (same name, contact type and email address or phone number).
  Expected: Similar to previous.

G.4. Deleting a contact

Deleting a contact in Heart²
1. Prerequisites: There are contacts in the list you are trying to delete (client or vendor list).
2. Test case: <CONTACT_TYPE>#1 delete
  Expected: The contact with ID #1 is deleted from the list. Details of the deleted contact are shown in the status message. Timestamp in the status bar is updated.
3. Test case: <CONTACT_TYPE>#0 delete
  Expected: No contact is deleted. Error details are shown in the status message. Status bar remains the same.
4. Other incorrect delete commands to try: <CONTACT_TYPE>3 delete, <CONTACT_TYPE>#x delete (where x is not a contact’s id), delete <CONTACT_TYPE>#1
  Expected: Similar to previous.

G.5. Updating a contact

Updating a contact that is present in Heart²
1. Prerequisites: There are contacts to be updated.
2. Test case: <CONTACT_TYPE>#1 update n/Test 2
  Expected: The contact with ID #1 has its name updated in Heart². Details of the updated contact are shown in the status message. Timestamp in the status bar is updated.
3. Test case: <CONTACT_TYPE>#0 update e/test@example.com
  Expected: No contact is updated. Error details are shown in the status message. Status bar remains the same.
4. Other incorrect update commands to try: updating a contact to another contact already present in Heart² (same name, contact type and email address or phone number).
  Expected: Similar to previous.

G.6. Viewing a contact

Viewing a contact that is present in Heart²
1. Prerequisites: The contact to be viewed is present in Heart².
2. Test case: <CONTACT_TYPE>#1 view
  Expected: The contact with ID #1 has its information displayed on the panel on the right of Heart². The contact card on the panel on the left of Heart² is selected.
3. Test case: <CONTACT_TYPE>#0 view
  Expected: The contact card on the panel on the left is empty. Error details are shown in the status message. Status bar remains the same.
4. Other incorrect view commands to try: client#1 view asdf, client view.
  Expected: Similar to previous.

G.7. Logging in

Log in to the application on new launch, or on log out.
1. Prerequisites: User must not already been logged in.
2. Test case: login u/rootUser p/rootPassword
  Expected: Successfully logged in as rootUser. Login GUI is closed, and the main screen GUI is shown. Your username and your account role (either a super_user or read_only_user) are shown at the footer of the app.
3. Test case: login u/YourCreatedUsername p/YourCreatedPassword
  Expected: Successfully logged in as YourCreatedUsername. Login GUI is closed, and the main screen GUI is shown. Your username and your account role (either a super_user or read_only_user) are shown at the footer of the app.
4. Incorrect commands to try: login u/YourCreatedUsername p/YourOldPassword, login u/YourCreatedUsername p/WrongPassword, login u/WrongUsername p/YourCreatedPassword
  Expected: Failed to log in. GUI remains on the same page, with a feedback saying that the username or password is wrong.
Log in to the application after logging in.
1. Prerequisites: User must have already logged in successfully and on the main screen GUI page.
2. Test case: login u/rootUser p/rootPassword
  Expected: Unknown command.

G.8. Logging out

Log out of the application
1. Test case: logout
  Expected: Successfully logged out. Main screen GUI is closed, and login screen GUI appears.

G.9. Registering a new account

Register a new account that can be used as login credentials subsequently.
1. Prerequisites: User account must be a SUPER_USER.
2. Test case: register account u/newUserName p/newPassword r/superuser
  Expected: Screen GUI feedback to say that you have successfully registered an account. You can now logout and log in with login u/newUserName p/newPassword.
3. Test case: register account u/us3r p/p@ssw0rD r/readonlyuser
  Expected: Screen GUI feedback to say that you have successfully registered an account. You can now logout and log in with login u/us3r p/p@ssw0rD.
4. Incorrect commands to try: login u/ p/password r/superuser, login u/username p/ r/readonlyuser (basically cannot contain empty field in any of u/ p/ or r/ parameter), login u/usernameAlreadyExist p/password r/superuser

G.10. Changing your account password

Change your current account password to a new password.
1. Prerequisites: You must know your old password.
2. Test case: change password o/rootPassword n/newPassword
  Expected: Screen GUI feedback to say that you have successfully changed your password. You can now logout and log in with login u/rootUser p/newPassword.
3. Incorrect commands to try: changepassword o/rootPassword n/newPassword, change password o/WrongOldPassword n/newPasword, change password o/rootPassword n/

G.11. Listing contacts

List all clients.
1. Test case: client list
  Expected: Screen GUI feedback to say that all client(s) listed. You can further verify whether each contact is a client.
List all vendors.
1. Test case: vendor list
  Expected: Screen GUI feedback to say that all vendor(s) listed. You can further verify whether each contact is a vendor.
List with parameters.
1. Test case: client list n/… p/… e/… a/… t/…
  Expected: List all clients that matches the parameters provided. Test with different combinations of parameters and invalid ones to verify functionality of list.
2. Test case: vendor list n/… p/… e/… a/… t/…
  Expected: List all vendors that matches the parameters provided. Test with different combinations of parameters and invalid ones to verify functionality of list.

G.12. Adding a new service request

Adding a new service to a client or vendor with no service requests
1. Prerequisites: You must create a new client or vendor with no service requests
2. Test case: <CONTACT_TYPE>#1 addservice s/photographer c/1000.00
  Expected: Service is added to the contact. Details of the service and the contact’s name shown in status message. You can now view the contact to rectify that the service is added with <CONTACT_TYPE>#1 view. This would display the contact’s information under "Service Requested" in the BrowserPanel on the right.
3. Incorrect commands to try: <CONTACT_TYPE>#1 addservice s/florist c/1000.00, <CONTACT_TYPE>#1 addservice s/photographer c/1000, <CONTACT_TYPE>#1 addservice s/photographer c/$1000.00
Adding a new service to a client or vendor with existing service requests
1. Prerequisites: You must have a client or vendor with at least one existing service request, that is not of photographer type
2. Test case: <CONTACT_TYPE>#1 addservice s/photographer c/1000.00
  Expected: Service is added to the contact. Details of the service and the contact’s name shown in status message. You can now view the contact to rectify that the service is added with <CONTACT_TYPE>#1 view. This would display the contact’s information under "Service Requested" in the BrowserPanel on the right, in addition to the existing services listed previously.
3. Incorrect commands to try: <CONTACT_TYPE>#1 addservice s/florist c/1000.00, <CONTACT_TYPE>#1 addservice s/photographer c/1000, <CONTACT_TYPE>#1 addservice s/photographer c/$1000.00
Adding a duplicate service to a client or vendor
1. Prerequisites: You must have a client or vendor with a photographer type service request
2. Test case: <CONTACT_TYPE>#1 addservice s/photographer c/1000.00
  Expected: Service is not added to the client. Duplicate service message shown in status message. You can now view the contact to rectify that the service is not overwritten with <CONTACT_TYPE>#1 view.

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Heart² - Developer Guide

1. Introduction

2. Setting Up

2.1. Prerequisites

2.2. Setting up the project in your computer

2.3. Verifying the setup

2.4. Configurations to do before writing code

2.4.1. Configuring the coding style

2.4.2. Updating documentation to match your fork

2.4.3. Setting up CI

2.4.4. Getting started with coding

3. Design

3.1. Architecture

Events-Driven nature of the design

3.2. UI component

3.3. Logic component

3.4. Model component

3.5. Storage component

3.6. Account Storage component

3.7. Common classes

4. Implementation

4.1. Undo/Redo feature

4.1.1. Current Implementation

4.1.2. Design Considerations

Aspect: How undo & redo executes

Aspect: Data structure to support the undo/redo commands

Aspect: What it shows after undo/redo command successfully executes

4.2. Logging

4.3. Configuration

4.4. Login Feature

4.4.1. Before logging in

4.4.2. After logging in

4.4.3. Design Considerations

Aspect: How to show the Login UI

4.5. Account creation

4.5.1. Types of account

4.5.2. Design Considerations

Aspect: Should the privilege be tied to Role enum or Account class?

Aspect: What type of access control to use?

4.6. Account storage

4.6.1. Design Considerations

Aspect: What file type to store user account as?

4.6.2. Security Considerations

Database

Storing password

4.7. Unique ID feature

4.7.1. Current Implementation

4.7.2. Design Considerations

Aspect: How should we refer to contacts in Heart²?

4.8. Add contact feature

4.8.1. Current Implementation

4.8.2. Design Considerations

Aspect: How should we store Client and Vendor objects in Heart²?

Aspect: How restrictive should the definition of a duplicate contact be?

4.9. Delete contact feature

4.9.1. Current Implementation

4.10. Update contact feature

4.10.1. Implementation

4.10.2. Design Considerations

Aspect: Should a similar (have the same name and same phone number or email) client and vendor object be updated together?

4.11. View contact feature

4.11.1. Implementation

4.11.2. Design Considerations

4.12. Adding a service request feature

4.12.1. Implementation

4.12.2. Design Considerations

Aspect 1: Cost storage

Aspect 2: Updating of Service request

4.13. Automatch feature

4.13.1. Implementation

4.13.2. Search Result Display

Profile

Tabular View

Design Considerations

Aspect: How should we store `Client` and `Vendor` objects in Heart²?

Aspect: Should a similar (have the same name and same phone number or email) `client` and `vendor` object be updated together?

`Logic` component

`Model` component

`Ui` component

`Storage` component

A.2. Creating a new command: `remark`

[Step 3] Ui: Add a placeholder for remark in `PersonCard`

[Step 4] Model: Add `Remark` class

[Step 5] Model: Modify `Person` to support a `Remark` field

[Step 6] Storage: Add `Remark` field to `XmlAdaptedPerson` class

[Step 6b] Test: Add withRemark() for `PersonBuilder`

[Step 7] Ui: Connect `Remark` field to `PersonCard`

[Step 8] Logic: Implement `RemarkCommand#execute()` logic