<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p><font face="Helvetica, Arial, sans-serif">Hi all,</font></p>
<p>I extended the class ol.source.VectorTile in order to load
VectorTiles in different formats (GeoJSON and MVT) from a local
GWC cache. While upgrading from OpenLayers v3.20 to OpenLayers
v4.x it seems that for MVT the scope in the "tileUrlFunction" gets
lost. It seems to be "window". For GeoJSON-based VectorTiles
everything is still running fine.</p>
<p>Below you find the crutial parts of my class:</p>
<p><tt>ol.inherits(ol.source.GWCVT, ol.source.VectorTile);</tt><tt><br>
</tt><tt><br>
</tt><tt>ol.source.GWCVT.prototype.tileUrlFunction =</tt><tt><br>
</tt><tt> function(tileCoord, pixelRatio, projection) {</tt></p>
<p><tt>// here 'this' becomes 'window' in the second call<br>
</tt></p>
<p><tt>// assembling the URL</tt><tt><br>
</tt><tt>// ...</tt><tt><br>
</tt></p>
<p><tt>}</tt></p>
<p><tt>ol.source.GWCVT.prototype.setTileUrlFunction =
function(tileUrlFunction) {</tt><tt><br>
</tt><tt><br>
</tt><tt>
ol.source.VectorTile.prototype.setTileUrlFunction.call(this,
tileUrlFunction);</tt><tt><br>
</tt><tt>};</tt></p>
<p>Thanks for any hint!</p>
Cheers<br>
Chris
</body>
</html>