[Commits] r168 - sandbox/opengeo/drake/trunk/core/lib/GeoExt/data

[commits at geoext.org]

Author: sbenthall
Date: 2009-02-13 23:54:58 +0100 (Fri, 13 Feb 2009)
New Revision: 168

Added:
   sandbox/opengeo/drake/trunk/core/lib/GeoExt/data/FeatureStore.js
Log:
FeatureStore with layer factory first hacky draft


Added: sandbox/opengeo/drake/trunk/core/lib/GeoExt/data/FeatureStore.js
===================================================================
--- sandbox/opengeo/drake/trunk/core/lib/GeoExt/data/FeatureStore.js	                        (rev 0)
+++ sandbox/opengeo/drake/trunk/core/lib/GeoExt/data/FeatureStore.js	2009-02-13 22:54:58 UTC (rev 168)
@@ -0,0 +1,115 @@
+Ext.namespace("GeoExt.data");
+
+GeoExt.data.FeatureStore = function(c) {
+    GeoExt.data.FeatureStore.superclass.constructor.call(
+        this,
+        Ext.apply(c, {
+            proxy: c.proxy || (!c.data ?
+                new Ext.data.HttpProxy({url: c.url, disableCaching: false, method: "GET"}) :
+                undefined
+            ),
+            reader: new GeoExt.data.FeatureReader(
+                c, c.fields || []
+            )
+        })
+    );
+};
+Ext.extend(GeoExt.data.FeatureStore, Ext.data.Store, {
+
+    //the constructor used by the createLayer method
+    layerConstructor : OpenLayers.Layer.Vector,
+
+    //a factory for creating a vector layer from this store
+    createLayer : function(name, layerConfig, options){
+
+        var layerConstructor = (options && options.layerConstructor) || this.layerConstructor;
+
+        var layer = new layerConstructor(name, layerConfig);
+
+        layer.store = this;
+
+        //should probably be in constructor
+        this.featureStoreMediator = new GeoExt.data.FeatureStoreMediator({
+            store: this
+        });
+
+        this.bindLayer(layer);
+
+        
+
+    }
+
+    /**
+     * API Method: bindStore
+     * In the parlance of Ext, this function takes a store, removes listeners
+     * on the store that it already has (if any), then ads the appropriate
+     * listeners to the new store while replacing the old with the new.
+     */
+     bindLayer : function(layer, initial){
+         if(layer.store && !initial){
+             this.un("load", this.layerHandlers.onLoad, layer);
+             this.un("loadexception", this.layerHandlers.onLoadException, layer);
+             this.un("add", this.layerHandlers.onAdd, layer);
+             this.un("remove", this.layerHandlers.onRemove, layer);
+         }
+
+         this.store.on("load", this.layerHandlers.onLoad, layer);
+         this.store.on("loadexception", this.layerHandlers.onLoadException, layer);
+         this.store.on("add", this.layerHandlers.onAdd, layer);
+         this.store.on("remove", this.layerHandlers.onRemove, layer);
+
+         var updateStore = function(){
+             this.update(layer);
+         }
+
+         layer.events.on({
+             featuresadded: updateStore,
+ 	     featuresremoved: updateStore,
+ 	     featuremodified: updateStore,
+ 	     scope: this
+         });
+
+    },
+
+    //contains handlers to be called in scope of created OpenLayers layer
+    layerHandlers : {
+        onLoad: function(store, options) {
+            this.removeFeatures(this.features);
+            store.each(function(record) {
+                this.addFeatures(this.getFeatureFromRecord(record));
+            }, this)
+        },
+    
+        onLoadException: function() {
+            // To be overridden by subclasses.
+        },
+    
+        onAdd: function(store, records, index) {
+            for (var index = 0; index < records.length; index++) {
+                this.addFeatures(this.getFeatureFromRecord(records[index]));
+            }  
+        },
+    
+        onRemove: function(store, record, index) {
+            this.removeFeatures(this.getFeatureFromRecord(record));
+        },
+    
+        getFeatureFromRecord: function(record) {
+            return record.data.feature;
+        }
+    },
+
+    /**
+     * Method: update
+     *      Called when features are added, removed or modified. This
+     *      function empties the store, loops over the features in
+     *      the layer, and for each feature calls the user-defined
+     *      filter function, if the return value of the filter function
+     *      evaluates to true the feature is added to the store.
+     */
+    update: function(layer) {
+        this.featureStoreMediator.addFeatures(
+            layer.features,
+            {append: false, filter: this.filter});
+    }
+});