Ticket #1622: mapguideHttpTile.patch

MapGuide.js

@@ -33 +33 @@
-    singleTile: false,
-    
-    /**
+     * APIProperty: useHttpTile
+     * {Boolean} use a tile cache exposed directly via a webserver rather than the 
+     *    via mapguide server. This does require extra configuration on the Mapguide Server,
+     *    and will only work when singleTile is false. The url for the layer must be set to the
+     *    webserver path rather than the Mapguide mapagent.   
+     *    See http://trac.osgeo.org/mapguide/wiki/CodeSamples/Tiles/ServingTilesViaHttp 
+     **/
+    useHttpTile: false,
+    
+    /**
-     * Constant: TILE_PARAMS
-     * {Object} Hashtable of default parameter key/value pairs for tiled layer
-     */
-    TILE_PARAMS: {
-         operation: 'GETTILEIMAGE',
-
+
+
+
+
-    },
-
-    /**
@@ -219 +232 @@
-          var rowidx = Math.floor((this.maxExtent.top-bounds.top)/currentRes);
-          rowidx = Math.round(rowidx/this.tileSize.h);
-
+          if (this.useHttpTile){
+              url = this.getImageFilePath(
+                       {
+                           tilecol: colidx,
+                           tilerow: rowidx,
+                           scaleindex: this.resolutions.length - this.map.zoom - 1
+                        });
+          
+          } else {
-          url = this.getFullRequestString(
-                       {
-                           tilecol: colidx,
@@ -226 +248 @@
-                           scaleindex: this.resolutions.length - this.map.zoom - 1
-                        });
-         }
+         }
-        
-        return url;
-    },
-
-    /**
-
-
-
-
+
+
-     *
-     * Parameters:
-     * altUrl - {String} Alternative base URL to use.
-     *
-     * Returns:
-layer's url appropriately encoded for MapGuid
+url for the tile imag
-     */
+    getImageFilePath:function(newParams, altUrl) {
+    
+    
+        // use layer's url unless altUrl passed in
+        var url = (altUrl == null) ? this.url : altUrl;
+        
+        // if url is not a string, it should be an array of strings, 
+        //  in which case we will randomly select one of them in order
+        //  to evenly distribute requests to different urls.
+        if (typeof url == "object") {
+            url = url[Math.floor(Math.random()*url.length)];
+        }   
+        // requestString always starts with url
+        var requestString = url;        
+
+        // create a new params hashtable with all the layer params and the 
+        // new params together. then convert to string
+        var allParams = OpenLayers.Util.extend({}, this.params);
+        allParams = OpenLayers.Util.extend(allParams, newParams);
+        // ignore parameters that are already in the url search string
+        var urlParams = OpenLayers.Util.upperCaseObject(
+                            OpenLayers.Util.getArgs(url));
+        for(var key in allParams) {
+            if(key.toUpperCase() in urlParams) {
+                delete allParams[key];
+            }
+        }
+        var paramsString = OpenLayers.Util.getParameterString(allParams);
+        
+        /* MapGuide needs '+' seperating things like bounds/height/width.
+           Since typically this is URL encoded, we use a slight hack: we
+           depend on the list-like functionality of getParameterString to
+           leave ',' only in the case of list items (since otherwise it is
+           encoded) then do a regular expression replace on the , characters
+           to '+' */
+        paramsString = paramsString.replace(/,/g, "+");
+
+        var tileRowGroup = ""
+        var tileColGroup = "";
+        
+        if (newParams.tilerow < 0)
+            tileRowGroup =  '-';
+            
+        if (newParams.tilerow == 0 )    
+            tileRowGroup += 0;
+        else
+            tileRowGroup += Math.floor(newParams.tilerow/this.TILE_PARAMS.tileRowsPerFolder) * this.TILE_PARAMS.tileRowsPerFolder ;
+            
+        if (newParams.tilecol < 0)
+            tileColGroup =  '-';
+        
+        if (newParams.tilecol == 0)
+            tileColGroup += 0;
+        else                
+            tileColGroup += Math.floor(newParams.tilecol/this.TILE_PARAMS.tileColumnsPerFolder) * this.TILE_PARAMS.tileColumnsPerFolder;                    
+        
+        var tilePath = '/S' + newParams.scaleindex
+                        + '/' + this.params.basemaplayergroupname
+                        + '/R' + tileRowGroup
+                        + '/C' + tileColGroup
+                        + '/' + (newParams.tilerow % this.TILE_PARAMS.tileRowsPerFolder) 
+                        + '_' + (newParams.tilecol % this.TILE_PARAMS.tileColumnsPerFolder) 
+                        + '.' + this.TILE_PARAMS.format;
+                        // +'?r='+newParams.tilerow+'&c='+newParams.tilecol;
+        
+        requestString +=tilePath;
+        
+        return requestString;
+    },
+    
-    getFullRequestString:function(newParams, altUrl) {
-        // use layer's url unless altUrl passed in
-        var url = (altUrl == null) ? this.url : altUrl;