Add On Demand Resources Support

[kapitoshka438]

Short description 📝

On-demand resources are app contents that are hosted on the App Store and are separate from the related app bundle that you download.
The resources can be of any type supported by bundles except for executable code. Supported on-demand resource types are described in Apple Developer Documentation.
Developers identify on-demand resources during development by assigning them one or more tags. A tag is a string identifier they create.

It's important for us to understand how are tags defined in generated pbxproj.

Tags assigned to resource files or folders are defined in targets PBXBuildFile section:

/* Begin PBXBuildFile section */
  ...
  6CD9B9A8A7B99902ADF2733A /* on-demand-data.txt in Resources */ = {isa = PBXBuildFile; fileRef = C76E1D013C995B4365F328A4 /* on-demand-data.txt */; settings = {ASSET_TAGS = (datafile, ); }; };
  ...
/* End PBXBuildFile section */

Tags assigned to assets in Asset Catalogs are not presented in pbxproj and defined in their Contents.json:

{
  ...
  "properties" : {
    "on-demand-resource-tags" : [
      "image"
    ]
  }
}

All tags assigned to any type of on-demand resources are listed in PBXProject section in alphabet order:

/* Begin PBXProject section */
		F6B39DFD5CF1C50192B21AD0 /* Project object */ = {
			isa = PBXProject;
			attributes = {
				BuildIndependentTargetsInParallel = YES;
				KnownAssetTags = (
					"ar-resource-group",
					"cube-texture",
					data,
				);
  ...
/* End PBXProject section */

On targets level, each tag is assigned to one of the categories below:

• Initial install tags (alphabet order)
• Prefetch tag order (order-sensitive)
• Dowloaded only on demand (alphabet order)

Initial install tags and Prefetched order tags are defined in the targets XCBuildConfiguration section:

814E5CB981F34CFCEFE45501 /* Release */ = {
			isa = XCBuildConfiguration;
			buildSettings = {
				...
				ON_DEMAND_RESOURCES_INITIAL_INSTALL_TAGS = "data\\ file json";
				ON_DEMAND_RESOURCES_PREFETCH_ORDER = "image-stack image tag\\ with\\ space";
				...

The last category is default, not described in pbxproj and represents all tags from KnownAssetTags excluding tags from the first two categories.

This pull request add support for on-demand resources.

• During project generation, we parse tags in all Contents.json in Asset Catalogs to generate KnownAssetTags (defining tags for file resources was already implemented).
• Target init has got additional parameters to define Initial Install Tags and Prefetch Order Tags

How to test the changes locally 🧐

This PR adds new fixture: ios_app_with_on_demand_resources, with acceptance, generation, edit and lint tests.

Contributor checklist ✅

• The code has been linted using run mise run lint:fix
• The change is tested via unit testing or acceptance testing, or both
• The title of the PR is formulated in a way that is usable as a changelog entry
• In case the PR introduces changes that affect users, the documentation has been updated

Reviewer checklist ✅

• The code architecture and patterns are consistent with the rest of the codebase
• Reviewer has checked that, if needed, the PR includes the label changelog:added, changelog:fixed, or changelog:changed, and the title is usable as a changelog entry

[kwridan]

Thank you @kapitoshka438 for the detailed investigation into this!

[kwridan]

thanks @kapitoshka438

[kwridan]

Thank you for all the updates @kapitoshka438

[kwridan]

@all-contributors add @kapitoshka438 for code

[allcontributors]

@kwridan

I've put up a pull request to add @kapitoshka438! 🎉

[pepicrft]

Some minor things. Thanks a lot for putting the work here.

[pepicrft]

@kapitoshka438 would you mind adding a README.md where you document the fixture that you added? After adding it the README will automatically surface in the documentation website and it'll be useful for Tuist users to see some examples.

[fortmarek]

Amazing work 👏