WMSGetFeatureInfo control: add support for mutiple WMS services, r=ahocevar (closes #2091)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9874 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/WMSGetFeatureInfo.js

@@ -31,6 +31,14 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
      */
     hover: false,
 
+    /**
+     * APIProperty: drillDown
+     * {Boolean} Drill down over all WMS layers in the map. When
+     *     using drillDown mode, hover is not possible, and an infoFormat that
+     *     returns parseable features is required. Default is false.
+     */
+    drillDown: false,
+
     /**
      * APIProperty: maxFeatures
      * {Integer} Maximum number of features to return from a WMS query. This
@@ -139,7 +147,10 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
      *      response (String), a *features* property with an array of the
      *      parsed features, an *xy* property with the position of the mouse
      *      click or hover event that triggered the request, and a *request*
-     *      property with the request itself.
+     *      property with the request itself. If drillDown is set to true and
+     *      multiple requests were issued to collect feature info from all
+     *      layers, *text* and *request* will only contain the response body
+     *      and request object of the last request.
      */
     EVENT_TYPES: ["beforegetfeatureinfo", "getfeatureinfo"],
 
@@ -167,6 +178,10 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
             );
         }
         
+        if(this.drillDown === true) {
+            this.hover = false;
+        }
+
         if(this.hover) {
             this.handler = new OpenLayers.Handler.Hover(
                    this, {
@@ -256,9 +271,8 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
      */
     findLayers: function() {
 
-        var layers = [];
-        
         var candidates = this.layers || this.map.layers;
+        var layers = [];
         var layer, url;
         for(var i=0, len=candidates.length; i<len; ++i) {
             layer = candidates[i];
@@ -267,15 +281,14 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
                 url = layer.url instanceof Array ? layer.url[0] : layer.url;
                 // if the control was not configured with a url, set it
                 // to the first layer url
-                if(!this.url) {
+                if(this.drillDown === false && !this.url) {
                     this.url = url;
                 }
-                if(this.urlMatches(url)) {
+                if(this.drillDown === true || this.urlMatches(url)) {
                     layers.push(layer);
                 }
             }
         }
-
         return layers;
     },
     
@@ -305,44 +318,24 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
     },
 
     /**
-     * Method: request
+     * Method: buildWMSOptions
-     * Sends a GetFeatureInfo request to the WMS
+     * Build an object with the relevant WMS options for the GetFeatureInfo request
      *
      * Parameters:
-     * clickPosition - {<OpenLayers.Pixel>} The position on the map where the
+     * url - {String} The url to be used for sending the request
-     *     mouse event occurred.
+     * layers - {Array(<OpenLayers.Layer.WMS)} An array of layers
-     * options - {Object} additional options for this method.
+     * clickPosition - {<OpenLayers.Pixel>} The position on the map where the mouse
-     * 
+     *     event occurred.
-     * Valid options:
+     * format - {String} The format from the corresponding GetMap request
-     * - *hover* {Boolean} true if we do the request for the hover handler
      */
-    request: function(clickPosition, options) {
+    buildWMSOptions: function(url, layers, clickPosition, format) {
-        options = options || {};
+        var layerNames = [], styleNames = [];
-        var layerNames = [];
-        var styleNames = [];
-
-        var layers = this.findLayers();
-        if(layers.length > 0) {
-
         for (var i = 0, len = layers.length; i < len; i++) { 
             layerNames = layerNames.concat(layers[i].params.LAYERS);
-                // in the event of a WMS layer bundling multiple layers but not
+            styleNames = styleNames.concat(this.getStyleNames(layers[i]));
-                // specifying styles,we need the same number of commas to specify
-                // the default style for each of the layers.  We can't just leave it
-                // blank as we may be including other layers that do specify styles.
-                if (layers[i].params.STYLES) {
-                    styleNames = styleNames.concat(layers[i].params.STYLES);
-                } else {
-                    if (layers[i].params.LAYERS instanceof Array) {
-                        styleNames = styleNames.concat(new Array(layers[i].params.LAYERS.length));
-                    } else { // Assume it's a String
-                        styleNames = styleNames.concat(layers[i].params.LAYERS.replace(/[^,]/g, ""));
         }
-                }
+        return {
-            }
+            url: url,
-    
-            var wmsOptions = {
-                url: this.url,
             params: OpenLayers.Util.applyDefaults({
                 service: "WMS",
                 version: "1.1.0",
@@ -357,7 +350,7 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
                 y: clickPosition.y,
                 height: this.map.getSize().h,
                 width: this.map.getSize().w,
-                    format: layers[0].params.FORMAT,
+                format: format,
                 info_format: this.infoFormat
             }, this.vendorParams),
             callback: function(request) {
@@ -365,16 +358,113 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
             },
             scope: this
         };
+    },
 
+    /**
+     * Method: getStyleNames
+     * Gets the STYLES parameter for the layer. Make sure the STYLES parameter
+     * matches the LAYERS parameter
+     * 
+     * Parameters:
+     * layer - {<OpenLayers.Layer.WMS>}
+     *
+     * Returns:
+     * {Array(String)} The STYLES parameter
+     */
+    getStyleNames: function(layer) {
+        // in the event of a WMS layer bundling multiple layers but not
+        // specifying styles,we need the same number of commas to specify
+        // the default style for each of the layers.  We can't just leave it
+        // blank as we may be including other layers that do specify styles.
+        var styleNames;
+        if (layer.params.STYLES) {
+            styleNames = layer.params.STYLES;
+        } else {
+            if (layer.params.LAYERS instanceof Array) {
+                styleNames = new Array(layer.params.LAYERS.length);
+            } else { // Assume it's a String
+                styleNames = layer.params.LAYERS.replace(/[^,]/g, "");
+            }
+        }
+        return styleNames;
+    },
+
+    /**
+     * Method: request
+     * Sends a GetFeatureInfo request to the WMS
+     * 
+     * Parameters:
+     * clickPosition - {<OpenLayers.Pixel>} The position on the map where the
+     *     mouse event occurred.
+     * options - {Object} additional options for this method.
+     * 
+     * Valid options:
+     * - *hover* {Boolean} true if we do the request for the hover handler
+     */
+    request: function(clickPosition, options) {
+        var layers = this.findLayers();
+        if(layers.length == 0) {
+            // Reset the cursor.
+            OpenLayers.Element.removeClass(this.map.viewPortDiv, "olCursorWait");
+            return;
+        }
+        
+        options = options || {};
+        if(this.drillDown === false) {
+            var wmsOptions = this.buildWMSOptions(this.url, layers,
+                clickPosition, layers[0].params.FORMAT); 
             var response = OpenLayers.Request.GET(wmsOptions);
     
             if (options.hover === true) {
                 this.hoverRequest = response.priv;
             }
         } else {
+            this._requestCount = 0;
+            this._numRequests = 0;
+            this.features = [];
+            // group according to service url to combine requests
+            var services = {}, url;
+            for(var i=0, len=layers.length; i<len; i++) {
+                var layer = layers[i];
+                var service, found = false;
+                url = layer.url instanceof Array ? layer.url[0] : layer.url;
+                if(url in services) {
+                    services[url].push(layer);
+                } else {
+                    this._numRequests++;
+                    services[url] = [layer]
+                }
+            }
+            var layers;
+            for (var url in services) {
+                layers = services[url];
+                var wmsOptions = this.buildWMSOptions(url, layers, 
+                    clickPosition, layers[0].params.FORMAT);
+                OpenLayers.Request.GET(wmsOptions); 
+            }
+        }
+    },
+
+    /**
+     * Method: triggerGetFeatureInfo
+     * Trigger the getfeatureinfo event when all is done
+     *
+     * Parameters:
+     * request - {XMLHttpRequest} The request object
+     * xy - {<OpenLayers.Pixel>} The position on the map where the
+     *     mouse event occurred.
+     * features - {Array(<OpenLayers.Feature.Vector>)}
+     */
+    triggerGetFeatureInfo: function(request, xy, features) {
+        this.events.triggerEvent("getfeatureinfo", {
+            text: request.responseText,
+            features: features,
+            request: request,
+            xy: xy
+        });
+
         // Reset the cursor.
         OpenLayers.Element.removeClass(this.map.viewPortDiv, "olCursorWait");
-        }
     },
     
     /**
@@ -393,16 +483,18 @@ OpenLayers.Control.WMSGetFeatureInfo = OpenLayers.Class(OpenLayers.Control, {
             doc = request.responseText;
         }
         var features = this.format.read(doc);
-
+        if (this.drillDown === false) {
-        this.events.triggerEvent("getfeatureinfo", {
+            this.triggerGetFeatureInfo(request, xy, features);
-            text: request.responseText,
+        } else {
-            features: features,
+            this._requestCount++;
-            request: request,
+            this._features = (this._features || []).concat(features);
-            xy: xy
+            if (this._requestCount === this._numRequests) {
-        });
+                this.triggerGetFeatureInfo(request, xy, this._features.concat()); 
-        
+                delete this._features;
-        // Reset the cursor.
+                delete this._requestCount;
-        OpenLayers.Element.removeClass(this.map.viewPortDiv, "olCursorWait");
+                delete this._numRequests;
+            }
+        }
     },
    
     /** 

tests/Control/WMSGetFeatureInfo.html

@@ -307,6 +307,51 @@
 
     }
 
+    function test_drillDown(t) {
+        t.plan(4);
+        var map = new OpenLayers.Map("map", {
+            getExtent: function() {return(new OpenLayers.Bounds(-180,-90,180,90));}
+            }
+        );
+
+        var a = new OpenLayers.Layer.WMS("dummy","http://localhost/wms", {
+            layers: "a"
+        });
+
+        var b = new OpenLayers.Layer.WMS("dummy","http://localhost/wms", {
+            layers: "c"
+        });
+
+        var c = new OpenLayers.Layer.WMS("dummy","http://myhost/wms", {
+            layers: "x"
+        });
+
+        map.addLayers([a, b, c]);
+
+        var click = new OpenLayers.Control.WMSGetFeatureInfo({
+            drillDown: true
+        });
+
+        map.addControl(click);
+
+        var count = 0;
+        var _request = OpenLayers.Request.GET;
+        OpenLayers.Request.GET = function(options) {
+            count++;
+            if (count == 1) {
+                t.eq(options.params["query_layers"].join(","), "a,c", "Layers should be grouped by service url");
+                t.eq(options.url, "http://localhost/wms", "Correct url used for first request");
+            } else if (count == 2) {
+                t.eq(options.url, "http://myhost/wms", "Correct url used for second request");
+            }
+        };
+        click.activate();
+        click.getInfoForClick({xy: {x: 50, y: 50}});
+        OpenLayers.Request.GET = _request;
+        t.eq(count, 2, "We expect 2 requests to go off");
+        map.destroy();
+    }
+
     </script>
 </head>
 <body>