volcanoscar / mvvm_hacker_news

Android MVVM experiment project using the official Data Binding library

MVVM using Data Binding

I wanted to experiment creating an MVVM structured project using the official Data Binding library, so I stripped back an old project of mine and replaced relevant codebase with an MVVM approach. This is still experimental, so I'd love to hear any suggestion / improvements to the approach!

Currently writing a Medium article which should explain more... but for now:

Posts

Post cards displayed on the Post Screen (left, above) are built using the following classes:

Post - The post object

PostAdapter - The RecyclerView adapter used to set the view model

PostViewModel - The view model used to manage the display of the posts

item_post - The XML layout file which displays the post card

Comments

Comments displayed on the Comment Screen (right, above) are built using the following classes:

Comment - The comment object

CommentAdapter - The RecyclerView adapter used to set the corresponding view model. Comments work a bit differently from posts as this adapter uses logic to choose to use one of two view models based on the comment type

CommentViewModel - The view model used for standard comments on a post

CommentsHeaderViewModel - The view model used as a header for the post text with an ASK post

item_comment - The XML layout file which displays a standard comment

item_comments_header - The XML layout file used to display the header for an ASK post

Requirements

• Android SDK.
• Android 5.1 (API 22) .
• Android SDK Tools
• Android SDK Build tools 23.0.0.0
• Android Support Repository
• Android Support library

Building

To build, install and run a debug version, run this from the root of the project:

./gradlew installRunDebug

Testing

To run unit tests on your machine using [Robolectric] (http://robolectric.org/):

./gradlew testDebugUnitTest

To run automated tests on connected devices:

./gradlew connectedAndroidTest