Fixes part of #59: Build app module views + view models with Bazel

[miaboloix]

Explanation

Fixes part of #59: Build app module view models with Bazel [BLOCKED: #1568]

In order to build app module in Bazel, parts of the module must be built before others in order to avoid circular dependencies and in order for data-binding to work.

In this PR, I am building the module's view models and views - which require certain listeners, resources, and annotation files (built in their own libraries). You will notice that I am building a resources library that excludes all layout resource files. This is necessary because layout files depend on view models, views, and binding adapters while binding adapters depend on view models.

See the graph below:

This is a visual representation of the libraries app module will have and how they will depend on eachother. The libraries in green are libraries implemented in this PR. The libraries in grey are implemented in PRs to follow.

Here is a quick summary of each library's function:

• listeners: Builds any listener files needed for views or view models
• annotations: Builds any scope annotation or helper files needed for the views or view models
• resources: Builds non-layout resource files
• views: Builds view files
• view models: Builds view model files
• databinding_adapters: Builds the custom binding adapter files under org/oppia/app/databinding/
• recyclerview_adapters: Builds the custom binding adapter files under org/oppia/app/recyclerview/
• databinding_resources: Builds layout files
• app: The complete app module library

NOTES:

1. Gradle does not build with this implementation yet but there are plans to write a custom macro to fix this issue.
2. If you have not set up Bazel for data-binding in Oppia Android, please follow the instructions laid out in this document.

To build views, run

~/bazel-databinding-new/bazel-bin/src/bazel build //:views --android_databinding_use_v3_4_args --experimental_android_databinding_v2 --override_repository=android_tools=/tmp/android_tools --java_header_compilation=false

To build view_models, run

~/bazel-databinding-new/bazel-bin/src/bazel build //:view_models --android_databinding_use_v3_4_args --experimental_android_databinding_v2 --override_repository=android_tools=/tmp/android_tools --java_header_compilation=false

Checklist

• The PR title starts with "Fix #bugnum: ", followed by a short, clear summary of the changes. (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
• The PR explanation includes the words "Fixes #bugnum: ..." (or "Fixes part of #bugnum" if the PR only partially fixes an issue).
• The PR follows the style guide.
• The PR does not contain any unnecessary auto-generated code from Android Studio.
• The PR is made from a branch that's not called "develop".
• The PR is made from a branch that is up-to-date with "develop".
• The PR's branch is based on "develop" and not on any other branch.
• The PR is assigned to an appropriate reviewer in both the Assignees and the Reviewers sections.

[BenHenning]

Thanks @miaboloix! This looks pretty close to done. Just had a few more comments.

[BenHenning]

Thanks @miaboloix! Overall LGTM, but the questions piece needs to be finished.

[BenHenning]

Also @miaboloix is this still blocked on #1568 per the title?

[miaboloix]

Also @miaboloix is this still blocked on #1568 per the title?

#1568 was merged, so it is unblocked now! I will rename it.

[BenHenning]

Thanks @miaboloix, LGTM!

[anandwana001]

@miaboloix Are we intentionally removing the vcs.xml file?
commit - 7a20fe1

[miaboloix]

@miaboloix Are we intentionally removing the vcs.xml file?
commit - 7a20fe1

No - this is a mistake. I meant to remove the file from the change list but I must have deleted it instead. Can I just revert this commit?