Add format-level layerOptions configuration property to WMC parser, to support

the configuration of user-preferred layer options in order to allow 
configurability of options like buffer, ratio, etc. r=ahocevar (Closes #1411).


git-svn-id: http://svn.openlayers.org/trunk/openlayers@6534 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

examples/wmc.html

@@ -19,7 +19,7 @@
         OpenLayers.IMAGE_RELOAD_ATTEMPTS = 2;
         OpenLayers.Util.onImageLoadErrorColor = "transparent";
         
-        var format = new OpenLayers.Format.WMC();
+        var format = new OpenLayers.Format.WMC({'layerOptions': {buffer: 0}});
         var doc, context, map;
         
         function init() {
@@ -137,7 +137,10 @@
         <button onclick="readWMC(true);">read and merge</button>
         <textarea id="wmc">paste WMC doc here</textarea>
 	<div id="docs">
-            This is an example of parsing WMC documents.
+            This is an example of parsing WMC documents. <br />
+            The format class has a layerOptions property, which can be used
+            to control the default options of the layer when it is created
+            by the parser.
 	</div>
   </body>
 </html>

lib/OpenLayers/Format/WMC.js

@@ -26,6 +26,14 @@ OpenLayers.Format.WMC = OpenLayers.Class({
      * {String} Specify a version string if one is known.
      */
     version: null,
+
+    /**
+     * Property: layerOptions
+     * {Object} Default options for layers created by the parser. These
+     *     options are overridden by the options which are read from the 
+     *     capabilities document.
+     */
+    layerOptions: null, 
     
     /**
      * Property: parser

lib/OpenLayers/Format/WMC/v1.js

@@ -193,11 +193,15 @@ OpenLayers.Format.WMC.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
      * {<OpenLayers.Layer.WMS>} A WMS layer.
      */
     getLayerFromInfo: function(layerInfo) {
+        var options = layerInfo.options;
+        if (this.layerOptions) {
+            OpenLayers.Util.applyDefaults(options, this.layerOptions);
+        }
         var layer = new OpenLayers.Layer.WMS(
             layerInfo.title,
             layerInfo.href,
             layerInfo.params,
-            layerInfo.options
+            options
         );
         return layer;
     },