Upgrade to ExtJS 4.0.0 - Released 04/26/2011

[extjs.git] / src / util / Sorter.js

diff --git a/src/util/Sorter.js b/src/util/Sorter.js
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+/**
+ * @class Ext.util.Sorter
+ * @extends Object
+ * Represents a single sorter that can be applied to a Store
+ */
+Ext.define('Ext.util.Sorter', {
+
+    /**
+     * @cfg {String} property The property to sort by. Required unless {@link #sorter} is provided
+     */
+    
+    /**
+     * @cfg {Function} sorterFn A specific sorter function to execute. Can be passed instead of {@link #property}
+     */
+    
+    /**
+     * @cfg {String} root Optional root property. This is mostly useful when sorting a Store, in which case we set the
+     * root to 'data' to make the filter pull the {@link #property} out of the data object of each item
+     */
+    
+    /**
+     * @cfg {Function} transform A function that will be run on each value before
+     * it is compared in the sorter. The function will receive a single argument,
+     * the value.
+     */
+    
+    /**
+     * @cfg {String} direction The direction to sort by. Defaults to ASC
+     */
+    direction: "ASC",
+    
+    constructor: function(config) {
+        var me = this;
+        
+        Ext.apply(me, config);
+        
+        //<debug>
+        if (me.property == undefined && me.sorterFn == undefined) {
+            Ext.Error.raise("A Sorter requires either a property or a sorter function");
+        }
+        //</debug>
+        
+        me.updateSortFunction();
+    },
+    
+    /**
+     * @private
+     * Creates and returns a function which sorts an array by the given property and direction
+     * @return {Function} A function which sorts by the property/direction combination provided
+     */
+    createSortFunction: function(sorterFn) {
+        var me        = this,
+            property  = me.property,
+            direction = me.direction || "ASC",
+            modifier  = direction.toUpperCase() == "DESC" ? -1 : 1;
+        
+        //create a comparison function. Takes 2 objects, returns 1 if object 1 is greater,
+        //-1 if object 2 is greater or 0 if they are equal
+        return function(o1, o2) {
+            return modifier * sorterFn.call(me, o1, o2);
+        };
+    },
+    
+    /**
+     * @private
+     * Basic default sorter function that just compares the defined property of each object
+     */
+    defaultSorterFn: function(o1, o2) {
+        var me = this,
+            transform = me.transform,
+            v1 = me.getRoot(o1)[me.property],
+            v2 = me.getRoot(o2)[me.property];
+            
+        if (transform) {
+            v1 = transform(v1);
+            v2 = transform(v2);
+        }
+
+        return v1 > v2 ? 1 : (v1 < v2 ? -1 : 0);
+    },
+    
+    /**
+     * @private
+     * Returns the root property of the given item, based on the configured {@link #root} property
+     * @param {Object} item The item
+     * @return {Object} The root property of the object
+     */
+    getRoot: function(item) {
+        return this.root == undefined ? item : item[this.root];
+    },
+    
+    // @TODO: Add docs for these three methods
+    setDirection: function(direction) {
+        var me = this;
+        me.direction = direction;
+        me.updateSortFunction();
+    },
+    
+    toggle: function() {
+        var me = this;
+        me.direction = Ext.String.toggle(me.direction, "ASC", "DESC");
+        me.updateSortFunction();
+    },
+    
+    updateSortFunction: function() {
+        var me = this;
+        me.sort = me.createSortFunction(me.sorterFn || me.defaultSorterFn);
+    }
+});
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