Absolute file URL is treated as mapbox: style URL

[ManuelRiegler]

Hi guys,
I try to use custom raster tiles in my project but I always get the following error:
"loading style failed: HTTP status code 401"

My MGLMapView is embed in an .xib file with just the default settings and I set the styleURL within the code (using local styles):

NSString *path = [[NSBundle mainBundle] pathForResource:@"alpstein_raster" ofType:@"json"]; styleURL = [NSURL URLWithString:path]; self.mapView.styleURL = styleURL;

My alpstein_raster json looks like:

{
  "version": 8,
  "name": "Alpstein",
  "sources": {
    "Alpstein-Summer": {
      "type": "raster",
      "tiles": [
        "http://xxx/AlpsteinSummer/{z}/{x}/{y}.png",
        "http://xxx/AlpsteinSummer/{z}/{x}/{y}.png",
        "http://xxx/AlpsteinSummer/{z}/{x}/{y}.png",
        "http://xxx/AlpsteinSummer/{z}/{x}/{y}.png"
      ],
      "tileSize": 256
      "maxzoom": 17
    }
  },

  "layers": [{
    "id": "Alpstein",
    "type": "raster",
    "source": "Alpstein-Summer",
    "paint": {
      "raster-fade-duration": 100
    }
  }]
}

I don´t set an AccessTokes since I don´t use MapBox Tilessources.
Any idea what I am doing wrong?
Tx for help,
Askin

[ManuelRiegler]

When I upload my JSON file to a webserver it works:
NSString *urlstr = @"http://www.someurl.com/alpstein_raster.json";
styleURL = [NSURL URLWithString:urlstr];

[1ec5]

MGLMapView is seeing an absolute file URL and treating it as a mapbox: URL. The workaround is to use a relative URL. Relative URLs are calculated relative to the main bundle:

[NSURL URLWithString:@"alpstein_raster"]

[RomainQuidet]

confirmed, it's working on local file with [NSURL URLWithString:@"asset://myfilename.json"]

[RomainQuidet]

@1ec5 Don't you think it would be useful to also expose the setStyleJSON api ? Users could need to load dynamically constructed json strings (versus files).

[ManuelRiegler]

tx guys -> [NSURL URLWithString:@"asset://alpstein_raster.json"]; works

[1ec5]

Hm, it shouldn’t be necessary to use the asset: protocol – that’s an implementation detail. A relative URL like myfilename.json is expected to work. Reopening because we should get absolute file URLs to work too. It’s just a matter of calculating the common base between an absolute file path and the path to the main bundle.

Don't you think it would be useful to also expose the setStyleJSON api ?

This API was exposed way back when, until we removed it in #1184 to reduce MGLMapView’s complexity. Moreover, passing a JSON file as a string was unwieldy for manipulating more than the most simple of styles, since you had to serialize back and forth (see cutting-room-floor/mapbox-gl-cocoa#31). There are plans to introduce a proper, object-oriented style API (#837), which would address this and other use cases.