Style: External graphic in project folder fails for SLD

[tsauerwein]

I have a point symbolizer with an external graphic, which is inside the project folder:

"layers": [
    {
      "type": "geojson",
      "geoJson": "file://resources/geojson.json",
      "style": {
        "version": "2",
        "graphicWidth": 32,
        "graphicHeight": 32,
        "*": {
          "symbolizers": [
            {
              "externalGraphic": "file://resources/marker-24.svg",
              "type": "point"
            }
          ]
        }
      }
    },

When I try to render, the style is not applied and I see the following in the logs:

16:33:16.744 [ForkJoinPool-1-worker-1] DEBUG o.m.p.h.ConfigFileResolvingHttpRequestFactory - Executing http request: file:/home/tsauerwein/projects/mapfish-printV3/examples/%7B%22graphicWidth%22:32,%22*%22:%7B%22symbolizers%22:%5B%7B%22externalGraphic%22:%22file:/resources/marker-24.svg%22,%22type%22:%22point%22%7D%5D%7D,%22graphicHeight%22:32,%22version%22:%222%22%7D
16:33:16.786 [ForkJoinPool-1-worker-1] DEBUG o.m.print.map.style.StyleParser - Loaded style from: 

 '{"graphicWidth":32,"*":{"symbolizers":[{"externalGraphic":"file://resources/marker-24.svg","type":"point"}]},"graphicHeight":32,"version":"2"}': 

<?xml version="1.0" encoding="UTF-8"?><sld:StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:sld="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:gml="http://www.opengis.net/gml" version="1.0.0"><sld:UserLayer><sld:LayerFeatureConstraints><sld:FeatureTypeConstraint/></sld:LayerFeatureConstraints><sld:UserStyle><sld:Name>Default Styler</sld:Name><sld:FeatureTypeStyle><sld:Name>name</sld:Name><sld:Rule><sld:MinScaleDenominator>4.9E-324</sld:MinScaleDenominator><sld:MaxScaleDenominator>1.7976931348623157E308</sld:MaxScaleDenominator><sld:PointSymbolizer><sld:Graphic><sld:ExternalGraphic><sld:OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="file://resources/marker-24.svg"/><sld:Format>image/svg</sld:Format></sld:ExternalGraphic><sld:Size>32.0</sld:Size></sld:Graphic></sld:PointSymbolizer></sld:Rule></sld:FeatureTypeStyle></sld:UserStyle></sld:UserLayer></sld:StyledLayerDescriptor>

The URL for the HTTP request to fetch the file is completely wrong.

(Using an absolute URL works fine.)

[tsauerwein]

For the JSON style definition the file path has to be given without the file://:

{
  "version": "2",
  "*": {
    "symbolizers": [
      {
        "externalGraphic": "marker.png",
        "graphicWidth": 32,
        "graphicOpacity" : 1.0,
        "graphicFormat" : "image/png",
        "type": "point"
      }
    ]
  }
}

But when the style is given as SLD it does not work neither with file:// nor without. The problem is that the ConfigFileResolvingHttpRequestFactory is not used from GeoTools to request the graphic. A possible solution would be to create a StyleVisitor which visits ExternalGraphic (similar to the OpacitySettingStyleVisitor) and replaces relative paths with absolute paths (while checking that the given file is inside the config folder).