Use Cases

Navigate this page:

1. UC-User
2. UC-Inventory
3. UC-Friends
4. UC-Browse/Search Inventories of Friends
5. UC-Trade with Friends
6. UC-Photographs of Items
7. UC-Offline Behaviour
8. UC-Configuration
9. UC-Top Traders
10. UC-Item Cloning

User

1
Use Case Name	CreateAccount
Participating Actors	Borrower or owner (primary)
Goal	Borrower or owner has an account
Trigger	Borrower or owner chooses the option to create an account
Precondition	Borrower or Owner has the application and knows their information for creating a new account
Postcondition	Borrower or Owner has an account and becomes a user of the application
Basic Flow	System prompts Borrower or Owner to enter their username, city, phone number, and email address. Borrower or Owner enters and submits the information. System creates an account with the information, and logs the user into the system.
Exceptions	2. If Borrower or Owner leaves one of the information blank or the username already exists   2.1. System displays an error message   2.2. System returns to step 1.
Constraints	Username is unique
Related Artifacts	11.01.01

2
Use Case Name	Login
Participating Actors	User
Goal	User accesses the system
Trigger	User requests to login
Precondition	User has an account and is not logged into the system
Postcondition	User is logged into the system
Basic Flow	System requests User to enter their username. User enters and submits their username. System validates the user information and logs user into the system.
Exceptions	3. If username does not exist   3.1. System displays an error message   3.2. System returns to step 1
Extends	CreateAccount, Logout
Related Artifacts	11.02.01

Top

---

Inventory

3
Use Case Name	AddItem
Participating Actors	Owner
Goal	Owner adds a new item to their inventory
Trigger	Owner chooses to add a new item to their inventory while viewing their inventory
Precondition	Owner wants to add a new item and knows the information to be entered for it
Postcondition	On success, the new item is added to the inventory
Basic Flow	System prompts Owner to upload a picture of the item and to enter its name, category, quality, quantity, visibility, price, and description. Owner enters and submits item information. System adds the new item to Owner's inventory.
Exceptions	3. If Owner does not enter the item name   3.1. System shows an error message   3.2. System prompts Owner to enter a name
Includes	SetItemVisibility, SetItemCategory
Related Artifacts	01.01.01

4
Use Case Name	EditItem
Participating Actors	Owner
Goal	Owner changes the inventory item information
Trigger	Owner is viewing one of their own item's details and chooses to modify it
Precondition	Owner knows the information to be modified
Postcondition	On success, the new item information is updated
Basic Flow	System displays the current item information. Owner modifies the item information and submits the new information. System changes the item information.
Exceptions	3. If Owner does not enter new information   3.1. System does not make any changes to the information   3.2. System returns to display the item's details
Includes	SetItemVisibility, SetItemCategory
Related Artifacts	01.01.01, 01.04.01

5
Use Case Name	RemoveItem
Participating Actors	Owner
Goal	Owner deletes the inventory item
Trigger	Owner chooses an item to be removed from the inventory
Precondition	Owner knows the item to be deleted and it exists in the inventory
Postcondition	On success, the item is removed from the owner's inventory
Basic Flow	System removes the item from the owner’s inventory.
Exceptions	1. If the item is currently in a pending trade   1.1 The system declines the pending trade   1.2 The system removes the item from inventory
Includes	DeclineTrade
Related Artifacts	01.01.01, 01.05.01

6
Use Case Name	ViewInventory
Participating Actors	Owner
Goal	Owner views their inventory and its details
Trigger	Owner chooses the Inventory option from their profile
Precondition	There are items in the owner's inventory
Postcondition	On success, Owner’s list of inventory items are displayed
Basic Flow	1. System displays the list of items in the owner's inventory.
Exceptions	1. If there are no items in the owner's inventory   1.1 System returns an error message   1.2 System returns to the owner's Profile page
Extends	ViewItem
Related Artifacts	01.02.01

7
Use Case Name	ViewItem
Participating Actors	Owner
Goal	Owner views an inventory item and its details
Trigger	Owner chooses a specific item from their inventory to view
Precondition	The item exists in the inventory and the owner knows the item to be viewed
Postcondition	On success, the item's information is displayed
Basic Flow	1. System displays the item information.
Exceptions
Related Artifacts	01.03.01

8
Use Case Name	SetItemVisibility
Participating Actors	Owner
Goal	Owner sets whether or not the item will be publicly displayed
Trigger	Owner chooses to edit or add an item
Precondition	Item exists in the inventory and Owner knows what the visibility should be set as
Postcondition	On success, the item's visibility will be set to public or private
Basic Flow	System displays the item information to be edited, including the options for visibility. Owner selects one and saves it. System updates the item’s visibility.
Exceptions
Related Artifacts	01.03.01, 03.02.01

9
Use Case Name	SetItemCategory
Participating Actors	Owner
Goal	Owner selects a category for an item
Trigger	Owner chooses to edit or add an item
Precondition	Item exists in the inventory and the owner knows what category the item should be set as
Postcondition	On success, the item will be placed in the chosen category
Basic Flow	System displays the item information to be edited, including the options for categories. Owner selects one and saves it. System updates the item’s category.
Exceptions
Related Artifacts	01.06.01

Top

---

Friends

10
Use Case Name	SearchUsername
Participating Actors	Owner
Goal	Owner finds another user
Trigger	Owner chooses the option to add a friend
Precondition	Owner knows at least part of the username to be searched
Postcondition	On success, a list of usernames matching the query is shown
Basic Flow	System prompts the owner to enter at least part of the username they want to search for. Owner submits the text query. System displays a list of matching users.
Exceptions	3. If there are no users that match the query   3.1. System displays no users
Related Artifacts	02.01.01

11
Use Case Name	AddFriend
Participating Actors	Owner (primary), User
Goal	Owner adds User to their friend list
Trigger	Owner chooses the Add Friend option while viewing the user's profile
Precondition	User exists and is not already on the Owner's friend list
Postcondition	On success, User is added to Owner’s friend list
Basic Flow	System adds User to Owner's friend list.
Exceptions
Related Artifacts	02.02.01

12
Use Case Name	RemoveFriend
Participating Actors	Owner (primary), User
Goal	Owner removes User from their friend list
Trigger	Owner chooses the user to be removed from their friend list
Precondition	User is in the owner's friend list
Postcondition	On success, User is removed from Owner’s friend list
Basic Flow	System removes User from Owner's friend list.
Exceptions
Related Artifacts	02.03.01

13
Use Case Name	ViewPersonalProfile
Participating Actors	Owner or Borrower
Goal	Owner or Borrower views their personal profile
Trigger	Owner or borrower chooses the Profile option
Precondition	Owner or Borrower has an account
Postcondition	On success, Owner or Borrower’s profile is displayed
Basic Flow	1. System displays the Owner or Borrower’s profile.
Exceptions
Related Artifacts	02.04.01

14
Use Case Name	ViewOtherProfile
Participating Actors	Owner or Borrower (primary), User
Goal	Owner or borrower views the profile of anyone they know of including friends
Trigger	Owner or borrower chooses a name from a list of users
Precondition	Owner or borrower can search for the user or has them on their friend list
Postcondition	On success, User's profile is displayed
Basic Flow	System displays the user’s profile.
Exceptions
Related Artifacts	02.05.01

Top

---

Browse/Search Inventories of Friends

15
Use Case Name	SearchFriendInventory
Participating Actors	Borrower
Goal	Borrower can browse the inventory of their friend
Trigger	Borrower chooses the Inventory option when viewing a friend's profile
Precondition	Owner is a friend of Borrower, Owner's inventory exists, and Owner has some items set to be publicly visible
Postcondition	On success, the owner's inventory information is displayed
Basic Flow	1. System displays Owner’s inventory of items that are publicly shared.
Exceptions	1. If no items are publicly shared or the owner does not have any items in their inventory   1.1 System displays no items
Constraints	Borrower can only see friend(owner)'s items that are marked as public visibility
Includes	BrowseInventoryByCategory, BrowseInventoryByTextQuery
Related Artifacts	03.01.01, 03.02.01

16
Use Case Name	BrowseInventoryByCategory
Participating Actors	Borrower
Goal	Borrower views a friend inventory by category
Trigger	Borrower is viewing an inventory and chooses to search by category
Precondition	Owner is a friend of Borrower, Owner's inventory exists, and Owner shares some of their items
Postcondition	On success, the friend inventory information is displayed by category
Basic Flow	System prompts Borrower to choose a category from a list. Borrower chooses a category. System displays a list of items in that category.
Exceptions	3. If the owner has no items that are publicly shared in that category   3.1 System displays an error message and returns to the inventory page
Constraints	Borrower can only see friend(owner)'s item marked as public
Related Artifacts	03.01.02, 03.02.01

17
Use Case Name	BrowseInventoryByTextQuery
Participating Actors	Borrower
Goal	Borrower views a friend inventory after entering a textual query
Trigger	Borrower is viewing an inventory and chooses to search by name
Precondition	Owner is a friend of Borrower, Owner's inventory exists, Owner shares some of their items, and Borrower knows part of the item name they want to search for
Postcondition	On success, Borrower will view items in a friend inventory that matches the textual query
Basic Flow	System prompts Borrower to enter a textual query. Borrower submits a textual query. System displays a list of items that matches the query.
Exceptions	2. If the borrower does not enter any text   2.1 System displays an error message and returns to the inventory page   3. If the owner has no items that are publicly shared and matches the textual query   3.1 System displays an error message and returns to the inventory page
Constraints	Borrower can only see friend(owner)'s item marked as public
Related Artifacts	03.01.03, 03.02.01

Top

---

Trade with Friends

18
Use Case Name	OfferTradeWithFriends
Participating Actors	Borrower (primary), Owner
Goal	Borrower offers a trade with an owner, and the trade consists of an item from the owner’s inventory and 0 or more items from the borrower’s inventory
Trigger	Borrower chooses the Trade option on an item in the owner’s inventory
Precondition	The item to be traded exists in Owner’s inventory
Postcondition	A trade request is sent to the owner
Basic Flow	System prompts the borrower to choose 0 or more items from the borrower’s inventory. Borrower selects the item(s) in their inventory that they want to trade. System sends a trade request to Owner.
Exceptions
Related Artifacts	04.01.01

19
Use Case Name	GetTradeNotifications
Participating Actors	Owner
Goal	Owner receives the trade request notification
Trigger	Borrower sends a trade request to Owner and Owner chooses to view their Offered Trades
Precondition	A trade request exists
Postcondition	The trade request is displayed to the owner
Basic Flow	System presents the new trade request information to Owner.
Exceptions
Includes
Related Artifacts	04.02.01

20
Use Case Name	AcceptTrade
Participating Actors	Owner
Goal	Owner accepts the trade
Trigger	Owner receives the trade notification and chooses the trade from the list of Offered Trades.
Precondition	The trade exists
Postcondition	The trade is accepted
Basic Flow	System prompts the owner to accept, decline, or counter the trade. Owner accepts the trade. System creates a transaction.
Exceptions
Includes	EmailTradeInfo
Related Artifacts	04.03.01

21
Use Case Name	DeclineTrade
Participating Actors	Owner
Goal	Owner declines trade
Trigger	Owner receives the trade notification and chooses the trade from the list of Offered Trades
Precondition	The trade exists
Postcondition	The trade is declined
Basic Flow	System prompts the owner to accept, decline, or counter the trade. Owner declines the trade. System removes the transaction from the owner's notification list.
Exceptions
Includes
Related Artifacts	04.03.01

22
Use Case Name	OfferCounterTrade
Participating Actors	Owner
Goal	Owner offers a counter trade initialized with the items of the suggested trade
Trigger	Owner chooses to decline a trade
Precondition	The trade exists
Postcondition	The counter trade request is sent to Borrower
Basic Flow	System prompts the owner to make a counter trade. Owner chooses to offer a counter trade. System displays items from initial trade and prompts the owner to choose 0 or more items from the owner's inventory. Owner selects the item(s) in their inventory that they want to trade. System sends a counter trade to the borrower. Borrower receives the counter trade notification.
Exceptions
Related Artifacts	04.04.01

23
Use Case Name	EditTrade
Participating Actors	Owner or borrower
Goal	Owner or Borrower edits the trade information
Trigger	Owner or Borrower chooses to edit a trade from a list of trades
Precondition	The trade exists
Postcondition	The trade information updates
Basic Flow	System displays the trade information. Owner or Borrower chooses which trade will be edited. System prompts Owner or Borrower to enter the new information. Owner enters and submits the new information. System makes a change to the trade information.
Exceptions	4. If Owner or Borrower does not enter new information   4.1. System does not make any changes to the trade   4.2. System returns to step 1
Includes
Related Artifacts	04.05.01

24
Use Case Name	DeleteTrade
Participating Actors	Borrower
Goal	Borrower deletes the trade
Trigger	Borrower is making a trade and chooses to cancel it
Precondition	The trade exists
Postcondition	On success, the list of trades are updated
Basic Flow	System prompts the borrower to confirm the deletion. Borrower chooses to confirm. System deletes the trade.
Exceptions
Includes
Related Artifacts	04.06.01

25
Use Case Name	EmailTradeInfo
Participating Actors	Owner (primary), borrower
Goal	Owner and borrower get emails of trade information
Trigger	Owner chooses to accept trade
Precondition	The trade exists and Owner chooses to accept the trade
Postcondition	On success, Owner and Borrower get emails of trade information
Basic Flow	System prompts owner to comment on how to continue the trade. Owner submits comment. System sends email to of trade details to Owner and Borrower.
Exceptions
Includes
Related Artifacts	04.07.01

26
Use Case Name	BrowsePastTrades
Participating Actors	Owner or Borrower
Goal	Owner or Borrower’s past trades are displayed
Trigger	Owner or Borrower chooses to view their past trades
Precondition	Owner or Borrower has past trades
Postcondition	On success, Owner or Borrower’s past trades are displayed
Basic Flow	System shows the Owner or Borrower's past trades.
Exceptions	1. If the owner or borrower has no past trades   1.1. System displays an error message and returns to main history
Includes
Related Artifacts	04.08.01, 04.09.01

27
Use Case Name	BrowseCurrentTrades
Participating Actors	Owner or Borrower
Goal	Owner or Borrower’s current trades are displayed
Trigger	Owner or Borrower chooses to view their current trades
Precondition	Owner or Borrower currently has trades pending or offered
Postcondition	On success, Owner or Borrower’s current trades are displayed
Basic Flow	System shows the Owner or Borrower's current trades.
Exceptions	1. If the owner or borrower has no current trades   1.1. System displays an error message and returns to main history
Includes
Related Artifacts	04.08.01, 04.09.01

28
Use Case Name	BrowseMySentTrades
Participating Actors	Owner or Borrower
Goal	Owner or Borrower’s trades that they offered are displayed
Trigger	Owner or Borrower chooses to view their pending trades
Precondition	Owner or Borrower has trades they have offered
Postcondition	On success, Owner or Borrower’s trades that they offered are displayed
Basic Flow	System shows trades that the Owner or Borrower have offered.
Exceptions	1. If the owner or borrower has no trades that they have offered   1.1. System displays an error message and returns to main trades
Includes
Related Artifacts	04.08.01, 04.09.01

29
Use Case Name	BrowseTradesOfferedToMe
Participating Actors	Owner or Borrower
Goal	Owner or Borrower’s trades that are offered to them are displayed
Trigger	Owner or Borrower chooses to view the trades offered to them
Precondition	Owner or Borrower has trades that were offered to them
Postcondition	On success, Owner or Borrower’s trades that are offered to them are displayed
Basic Flow	System shows the trades offered to the owner or borrower.
Exceptions	1. If the owner or borrower has no trades offered to them   1.1. System displays an error message and returns to main trades
Includes	BrowseCurrentTrade, BrowsePastTrade
Related Artifacts	04.08.01, 04.09.01

30
Use Case Name	SetTradeToComplete
Participating Actors	Owner
Goal	Owner sets the trade to the completed status
Trigger	Owner viewing the trade details and chooses to set the trade to complete
Precondition	The trade exists and the owner and borrower have completed the trade
Postcondition	On success, the trade is set to complete
Basic Flow	System displays the trade information to the owner. Owner sets the trade status to complete. System sets the trade to complete and adds it to the owner's Completed Trades history.
Exceptions
Related Artifacts	04.10.01

31
Use Case Name	BrowseCompleteTrades
Participating Actors	Owner or Borrower
Goal	Owner or Borrower’s trades that were completed are displayed
Trigger	Owner or Borrower can choose to view their completed trades
Precondition	Owner or Borrower has completed trades
Postcondition	On success, Owner or Borrower's completed trades are displayed
Basic Flow	System displays the owner or borrower's completed trades.
Exceptions	1. If the owner or borrower has no completed trades   1.1. System displays an error message and returns to the main history
Includes	BrowsePastTrade
Related Artifacts	04.12.01

Top

---

Photographs of Items

32
Use Case Name	AttachItemPhotograph
Participating Actors	Owner
Goal	Owner attaches a photograph to an item
Trigger	Owner chooses to modify or add an item
Precondition	Owner has a gallery and item photos on it
Postcondition	On success, the item's photograph is attached to the item
Basic Flow	System prompts owner to attach a photograph. Owner selects photograph from their gallery. System attaches the photograph to the item description.
Exceptions
Constraints	Image file must be under 65536 bytes in size
Related Artifacts	06.01.01, 06.04.01

33
Use Case Name	ViewItemPhotograph
Participating Actors	Owner
Goal	Owner views the image attached to an item
Trigger	Owner chooses an item to view
Precondition	Item has photographs attached
Postcondition	On success, the photograph of the item is displayed
Basic Flow	System displays the item's information and its photograph.
Exceptions
Extends	DeleteItemPhotograph
Related Artifacts	06.02.01

34
Use Case Name	DeleteItemPhotograph
Participating Actors	Owner
Goal	Owner deletes any attached photograph on an item
Trigger	Owner chooses to modify or add an item
Precondition	Item has photographs attached
Postcondition	On success, item photographs are removed from the item details
Basic Flow	System displays item information and its photograph. Owner selects the photograph. System prompts Owner whether or not they want to delete the photograph. Owner agrees to delete the photograph. System removes the photo from the item.
Exceptions
Related Artifacts	06.03.01

35
Use Case Name	EnablePhotographDownload
Participating Actors	User
Goal	User is able to see item photographs
Trigger	User chooses the Setting option
Precondition	Item has photos
Postcondition	On success, item photographs will be displayed
Basic Flow	System displays the user’s settings. User enables photograph download. System shows item photographs when the user browses an inventory.
Exceptions
Related Artifacts	06.05.01, 10.01.01

36
Use Case Name	DisablePhotographDownload
Participating Actors	User
Goal	User becomes unable to see item photographs
Trigger	User chooses the Setting option
Precondition	Item has photos
Postcondition	On success, item photographs will not be displayed
Basic Flow	System displays the user’s settings. User disables photograph download. System does not show item photographs when the user browses an inventory.
Exceptions
Related Artifacts	06.05.01, 10.01.01

Top

---

Offline Behaviour

37
Use Case Name	MakeInventoryItemsOffline
Participating Actors	Owner
Goal	Owner creates inventory items while offline, and pushes application and expenses information online once they get connectivity
Trigger	Owner chooses to add a new item to their inventory
Precondition	Owner has a new item to create, but does not have connectivity on their phone
Postcondition	On success, item is added automatically once Owner gets connectivity
Basic Flow	System prompts the owner with item detail prompts. Owner enters the information and submits it to the system. System saves the information and adds it to the owner’s inventory once the owner is reconnected.
Exceptions
Includes	AddItemToInventory
Related Artifacts	09.01.01

38
Use Case Name	MakeTradeOffline
Participating Actors	Borrower
Goal	Borrower requests a trade offline and the system sends the request online once the borrower gets connected
Trigger	Borrower chooses to make a trade while they are not connected
Precondition	Borrower would like to make a trade request with a friend, borrower knows what item they would like from their friend, and the borrower is not connected
Postcondition	On success, the trade request is made once the borrower is online
Basic Flow	System prompts the borrower for information regarding the trade request. Borrower enters the information. System saves the information and sends the trade request when the borrower is online.
Exceptions	2. If the owner removes the item while the borrower is offline   2.1 System displays an error message to the borrower   2.2 System removes the trade from the borrow's pending trades
Includes	OfferTradeWithFriends, DeleteTrade
Related Artifacts	09.02.01

39
Use Case Name	BrowseFriendInventoryOffline
Participating Actors	Borrower
Goal	Owner is able to view friend inventories offline that have been previously viewed while online
Trigger	Owner chooses to view a friend inventory
Precondition	Owner has viewed the inventory before and the system has the inventory cached in its memory
Postcondition	On success, the owner sees their friend’s inventory list
Basic Flow	System displays the saved friend inventory.
Exceptions
Related Artifacts	09.03.01

Top

---

Configuration

40
Use Case Name	EditProfile
Participating Actors	User
Goal	User changes their profile information
Trigger	User chooses the option to edit their profile
Precondition	User has an account and knows the information they want to change
Postcondition	On success, the user’s profile information is changed
Basic Flow	System displays the user's current profile information. User modifies and submits the new information. System changes the user's profile.
Exceptions	3. If the user does not enter new information   3.1. System does not make any changes to the information   3.2. System returns to display the user's profile
Extends	ViewPersonalProfile
Related Artifacts	10.02.01

Top

---

Top Traders

41
Use Case Name	ViewTopTraders
Participating Actors	User
Goal	User views the top traders on their friend list
Trigger	User chooses to view the top traders in their friend list
Precondition	User has friends and the user's friends have made trades
Postcondition	On success, the user's top traders are displayed
Basic Flow	System displays top traders on the user's friend list.
Exceptions	1. If the user has no friends on their friend list   1.1. System displays and error message and returns to the user's friend list
Related Artifacts	12.01.01

Top

---

Item Cloning

42
Use Case Name	CloneItem
Participating Actors	Owner
Goal	Owner clones another user's item into the owner's inventory
Trigger	Owner chooses to clone an item while viewing another user's item
Precondition	Owner owns the item and User has the item set to be viewed publicly
Postcondition	On success, the owner has the cloned item in their inventory
Basic Flow	System creates a copy of the item and adds it to the owner's inventory.
Exceptions
Related Artifacts	13.01.01

Top

---