Coding Challenge

Installation

• Clone this repo https://github.com/neutze/mobile-ios-app-cfw.git
• Navigate to the folder and subfolder cfw
• Open cfw.xcworkspace and run the project on a device or simulator (optimized for iPhone XR)

Documentation

Problem Statement

Currently, there is no visibility for ranking and scores of participants from CrossFit Werk. In order to encourage motivation / competition, it is important to surface the Open's score to all participants.

Assumptions for the Challenge

Participants scores are recorded by CFW however, there is no medium to surface this information.

Hypothesis

I believe that providing a score chart of participants will result in increase completion rate and higher scores because I think that it will increase motivation and competitive spirit.

How to measure success

• [Primary metric] Overall completion of participants who signed up for the challenge
• [Secondary metric] Increase in average score of the class

Solution

Show list of participants with the most important information that will validate the hypothesis (name, score, rank).

Acceptance Criteria

When application is opened, the download starts

• [On success] Display list of participants with rank and score
• [On error] Offer possibility to retry the download

Local storage is out of scope for the MVP

Technical Solution

Technology: iOS

Language: Swift

Testing Frameworks: XCode Test Navigator

Backend: mockable.io

Setup for the Challenge

• GitHub repository and project
• .gitignore
• README
• LICENSE
• Codacy
• mockable.io

Technical Design & Whiteboarding

API Endpoint

{
 "athletes" : [
    {
        "id" : 51,
        "name": "Johannes Neutze",
        "score": 232,
    },
    {
        "id" : 43,
        "name": "Stefan Rothlehner",
        "score": 201,
    },
    {
        "id" : 1,
        "name": "Henning Heinrich",
        "score": 9,
    },
    {
        "id" : 5,
        "name": "Inga Tiedmers",
        "score": 48,
    },
    {
        "id" : 2,
        "name": "Hannes Klein",
        "score": 12,
    }
    ]
}

Wireframes

List

Error

Architecture

Model

View Entity

Challenges faced during Project

iOS blocking http URLs

Since the provided mockable.io URL was only http and not https, iOS was blocking the connection to the endpoint. In order to fix this problem, I googled the error and found several solutions on stackoverflow. They all suggested to edit NSAppTransportSecurity in the info.plist. Even though there were a lot of similar solutions, none of the them worked in this case. In the end I fixed it by just changing the http URL to https and it worked without problems.

Working without Dependency Injection and Mock

In real projects, dependency injection and mock are fundamentals parts of development. Setting it up for a challenge requires initial effort that is covered by the advantages. Thus in a real project, this should be the first thing to be set up.

Race condition between pull to refresh and dialog

When receiving the result from downloading data and it is an error, a dialog is shown. This blocks the animation of pull to refresh to complete and thus stays in the loading state. In order to prevent this from happening, a delay for the dialog is added so the animation can finish first.

Time invested

~16 hours over three days

Next steps

The next steps of development would be

Development

• More tests using mock as well as instrumented tests
• Dependency Injection
• RxSwift
• Dependency Management using CocoaPods or Carthage
• Codacy and/or linting for code quality
• CI system for testing and deployment

Monitoring

• Firebase Crashlytics for stability tracking
• Firebase Performance for UI and network performance observation
• Firebase RemoteConfig for A/B testing

UX

• Information architecture
• Response to user actions (Loading indicators, different states, error handling, UI refactoring)
• Layout adjustments to serve different device types

Features

• AppIcon and nicer setup
• Athlete Images, workout details and result submission
• Local persistance