iOS: No longer able to load local Sprite resources

[picciano]

I am setting a custom style in my app, as follows:

NSString *jsonFile = [[NSBundle mainBundle] pathForResource:@"tallygo-v7" ofType:@"json"];
NSURL *styleURL = [NSURL URLWithString:[NSString stringWithFormat:@"asset://%@", jsonFile]];
[self.mapView setStyleURL:styleURL];

However, the sprite sheet (in the app bundle) is no longer loading. This URL was working in previous versions by inserting the URL into the raw JSON at runtime, but is now no longer found:

asset:///Users/picciano1/Library/Developer/CoreSimulator/Devices/7A8973A8-E8B6-4D23-85BE-25B92FBC0067/data/Containers/Bundle/Application/4ECBD40F-A759-4279-AC15-C5D1C20B4316/TallyGo.app/tallygo

The files are located at the root level of the main bundle. I have tried various paths without success:

asset://tallygo
asset:///tallygo
tallygo

I have even tried hard-coding the absolute path above into the style JSON.

Is there any way to do this now?

[1ec5]

The asset: URL scheme looks inside MapboxGL.bundle due to #1012. To point inside your app’s main bundle, you should be able to pass in a relative or absolute path to it. Does that work for you?

[picciano]

I have tried that and it no longer seems to be working. Note that I am referring to the Sprite assets, not the style JSON. The style is loading, however, the Sprite assets are not.

[1ec5]

You’re right, none of this is working correctly right now. As far as the GL backend is concerned, there can only be HTTP(S) URLs backed by HTTPRequestImpl and asset: URLs backed by AssetRequestImpl. (mapbox: URLs are normalized to HTTP in mbgl::util::mapbox::normalizeURL().) Passing in a file: URL trips an assertion in HTTPRequestImpl::handleResult(), but of course we shouldn’t be in there anyways.

Passing in an asset: URL doesn’t work either because AssetRequestImpl assumes mbgl::platform::assetRoot() to be its root. #1012 changed that root from the app bundle to MapboxGL.bundle, which is where we put various things like the compass image.

[1ec5]

@picciano To answer your specific situation, where did you put your sprite JSON and how did you name it? If the style JSON has style set to asset://tallygo, Sprite expects the sprite JSON to exist at MapboxGL.bundle/tallygo.json or MapboxGL.bundle/[email protected], with the sprite sheet in the same place (.png instead of .json).

[1ec5]

(As a temporary workaround, you can also dig yourself out of MapboxGL.bundle with a bunch of ../’s, but obviously we need a way to specify relative local paths.)

[picciano]

I put the style JSON and sprite files at the root level of the main application bundle.
tallygo-v7.json
tallygo.json
tallygo.png
[email protected]
[email protected]

I just tried asset://../tallygo and that worked. Good workaround. Is this captured somewhere else? Or should we leave this issue open until a real fix is in place?

[1ec5]

Let’s leave this issue open.

[incanus]

This has a workaround and is not critical for b2.

[incanus]

I am seeing style assets at the app bundle root working fine as asset://foo.json currently.

[incanus]

Ah, we do have differing code paths based on the Mapbox SDK integration method. What I mentioned above only works in the Mapbox GL.app test app, but when, say, you use Swift and CocoaPods, Xcode assembles the Foo.app and Mapbox.framework build products dynamically and the paths are different.

[friedbunny]

The ../ path traversal workaround no longer works. Workaround for the workaround is to use HTTP(S) URLs.

[picciano]

This is no longer an issue for us since we can now use client-side images for annotations. Much better than custom sprite sheets!

[1ec5]

This is no longer an issue for us since we can now use client-side images for annotations.

This is definitely the way to go nowadays if you want custom images.