prnvptl / PoliticalPreparedness

Android - Political Elections & Representatives - MVVM (repository pattern) + ViewModel + LiveData + Data Binding + Room Database + Koin (dependency injection)

Political Preparedness

PolitcalPreparedness is an example application built to demonstrate core Android Development skills recommended by Google.

This app demonstrates the following views and techniques:

MVVM (repository pattern) + ViewModel + LiveData + Data Binding + Room Database + Koin (dependency injection)

• Retrofit to make api calls to an HTTP web service.
• Moshi which handles the deserialization of the returned JSON to Kotlin data objects.
• Glide to load and cache images by URL.
• Room for local database storage.
• Koin a pragmatic lightweight dependency injection framework for Kotlin
• Motion Layout to create animations and motion

It leverages the following components from the Jetpack library:

• ViewModel
• LiveData
• Data Binding with binding adapters
• Navigation with the SafeArgs plugin for parameter passing between fragments

Setting up the Repository

To get started with this project, simply pull the repository and import the project into Android Studio. From there, deploy the project to an emulator or device.

• NOTE: In order for this project to pull data, you will need to add your API Key to the project as a value in the CivicsHttpClient. You can generate an API Key from the Google Developers Console

Android UI/UX

• Build a navigable interface consisting of multiple screens of functionality and data:
  • Application includes at least three screens with distinct features using either the Android Navigation Controller or Explicit Intents.
  • The Navigation Controller is used for Fragment-based navigation and intents are utilized for Activity-based navigation.
  • An application bundle is built to store data passed between Fragments and Activities.
• Construct interfaces that adhere to Android standards and display appropriately on screens of different size and resolution.
  • Application UI effectively utilizes ConstraintLayout to arrange UI elements effectively and efficiently across application features, avoiding nesting layouts and maintaining a flat UI structure where possible.
  • Data collections are displayed effectively, taking advantage of visual hierarchy and arrangement to display data in an easily consumable format.
  • Resources are stored appropriately using the internal res directory to store data in appropriate locations including string values, drawables, colors, dimensions, and more.
  • Data collections should be loaded into the application using ViewHolder pattern and appropriate View, such as RecyclerView.
• Animate UI components to better utilize screen real estate and create engaging content.
  • Application contains at least 1 feature utilizing MotionLayout to adapt UI elements to a given function. This could include animating control elements onto and off screen, displaying and hiding a form, or animation of complex UI transitions.
  • MotionLayout behaviors are defined in a MotionScene using one or more Transition nodes and ConstraintSet blocks.
  • Constraints are defined within the scenes and house all layout params for the animation.

Local and Network data

• Connect to and consume data from a remote data source such as a RESTful API.
  • The Application connects to at least 1 external data source using Retrofit or other appropriate library/component and retrieves data for use within the application.
  • Data retrieved from the remote source is held in local models with appropriate data types that are readily handled and manipulated within the application source. Helper libraries such as Moshi may be used to assist with this requirement.
  • The application performs work and handles network requests on the appropriate threads to avoid stalling the UI.
• Load network resources, such as Bitmap Images, dynamically and on-demand.
  • The Application loads remote resources asynchronously using an appropriate library such as Glide or other library/component when needed.
  • Images display placeholder images while being loaded and handle failed network requests gracefully.
  • All requests are performed asynchronously and handled on the appropriate threads..
• Store data locally on the device for use between application sessions and/or offline use.
  • The application utilizes storage mechanisms that best fit the data stored to store data locally on the device. Example: SharedPreferences for user settings or an internal database for data persistence for application data. Libraries such as Room may be utilized to achieve this functionality.
  • Data stored is accessible across user sessions.
  • Data storage operations are performed on the appropriate threads as to not stall the UI thread.
  • Data is structured with appropriate data types and scope as required by application functionality.

Android system and hardware integration

• Architect application functionality using MVVM.
  • Application separates responsibilities amongst classes and structures using the MVVM Pattern:
    • Fragments/Activities control the Views
    • Models houses the data structures,
    • ViewModel controls business logic.
  • Application adheres to architecture best practices, such as the observer pattern, to prevent leaking components, such as Activity Contexts, and efficiently utilize system resources.
• Implement logic to handle and respond to hardware and system events that impact the Android Lifecycle.
  • Beyond MVVM, the application handles system events, such as orientation changes, application switching, notifications, and similar events gracefully including, but not limited to:
    • Storing and restoring state and information
    • Properly handling lifecycle events in regards to behavior and functionality: Implement bundles to restore and save data
    • Handling interaction to and from the application via Intents
    • Handling Android Permissions.
• Utilize system hardware to provide the user with advanced functionality and features.
  • Application utilizes at least 1 hardware component to provide meaningful functionality to the application as a whole. Suggestion options include:
    • Camera
    • Location
    • Accelerometer
    • Microphone
    • Gesture Capture
    • Notifications
  • Permissions to access hardware features are requested at the time of use for the feature.
  • Behaviors are accessed only after permissions are granted.

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