MVC
Reactive Programming paradigms and android.arch.lifecycle.ViewModel allow for the following changes to MVC on Android:
- UI elements listen to a ViewModel and ONLY update themselves when something changes.
- Controllers listen for UI interactions and update the ViewModel accordingly.
- Controllers hold a reference to a ViewModel rather than a View
- Controllers only ever respond to ui interactions, a UI can not ask the controller to do something.
Emit change
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--------v-------- ---------------- ----------------
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| (Model) | Listen | (View) | | (Controller) |
| ViewModel *--------| Activity | | |
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----------------- -------*-------- ----------------
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Listen for UI interactions
Unit testing
The behaviour of the ViewModel can be easily tested, please see com.memtrip.mvmp.presenter.app.cake.CakeControllerTests.java