Upgrade to ExtJS 3.0.0 - Released 07/06/2009
[extjs.git] / src / state / Provider.js
diff --git a/src/state/Provider.js b/src/state/Provider.js
new file mode 100644 (file)
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+/*!
+ * Ext JS Library 3.0.0
+ * Copyright(c) 2006-2009 Ext JS, LLC
+ * licensing@extjs.com
+ * http://www.extjs.com/license
+ */
+/**
+ * @class Ext.state.Provider
+ * Abstract base class for state provider implementations. This class provides methods
+ * for encoding and decoding <b>typed</b> variables including dates and defines the
+ * Provider interface.
+ */
+Ext.state.Provider = function(){
+    /**
+     * @event statechange
+     * Fires when a state change occurs.
+     * @param {Provider} this This state provider
+     * @param {String} key The state key which was changed
+     * @param {String} value The encoded value for the state
+     */
+    this.addEvents("statechange");
+    this.state = {};
+    Ext.state.Provider.superclass.constructor.call(this);
+};
+Ext.extend(Ext.state.Provider, Ext.util.Observable, {
+    /**
+     * Returns the current value for a key
+     * @param {String} name The key name
+     * @param {Mixed} defaultValue A default value to return if the key's value is not found
+     * @return {Mixed} The state data
+     */
+    get : function(name, defaultValue){
+        return typeof this.state[name] == "undefined" ?
+            defaultValue : this.state[name];
+    },
+
+    /**
+     * Clears a value from the state
+     * @param {String} name The key name
+     */
+    clear : function(name){
+        delete this.state[name];
+        this.fireEvent("statechange", this, name, null);
+    },
+
+    /**
+     * Sets the value for a key
+     * @param {String} name The key name
+     * @param {Mixed} value The value to set
+     */
+    set : function(name, value){
+        this.state[name] = value;
+        this.fireEvent("statechange", this, name, value);
+    },
+
+    /**
+     * Decodes a string previously encoded with {@link #encodeValue}.
+     * @param {String} value The value to decode
+     * @return {Mixed} The decoded value
+     */
+    decodeValue : function(cookie){
+        var re = /^(a|n|d|b|s|o)\:(.*)$/;
+        var matches = re.exec(unescape(cookie));
+        if(!matches || !matches[1]) return; // non state cookie
+        var type = matches[1];
+        var v = matches[2];
+        switch(type){
+            case "n":
+                return parseFloat(v);
+            case "d":
+                return new Date(Date.parse(v));
+            case "b":
+                return (v == "1");
+            case "a":
+                var all = [];
+                var values = v.split("^");
+                for(var i = 0, len = values.length; i < len; i++){
+                    all.push(this.decodeValue(values[i]));
+                }
+                return all;
+           case "o":
+                var all = {};
+                var values = v.split("^");
+                for(var i = 0, len = values.length; i < len; i++){
+                    var kv = values[i].split("=");
+                    all[kv[0]] = this.decodeValue(kv[1]);
+                }
+                return all;
+           default:
+                return v;
+        }
+    },
+
+    /**
+     * Encodes a value including type information.  Decode with {@link #decodeValue}.
+     * @param {Mixed} value The value to encode
+     * @return {String} The encoded value
+     */
+    encodeValue : function(v){
+        var enc;
+        if(typeof v == "number"){
+            enc = "n:" + v;
+        }else if(typeof v == "boolean"){
+            enc = "b:" + (v ? "1" : "0");
+        }else if(Ext.isDate(v)){
+            enc = "d:" + v.toGMTString();
+        }else if(Ext.isArray(v)){
+            var flat = "";
+            for(var i = 0, len = v.length; i < len; i++){
+                flat += this.encodeValue(v[i]);
+                if(i != len-1) flat += "^";
+            }
+            enc = "a:" + flat;
+        }else if(typeof v == "object"){
+            var flat = "";
+            for(var key in v){
+                if(typeof v[key] != "function" && v[key] !== undefined){
+                    flat += key + "=" + this.encodeValue(v[key]) + "^";
+                }
+            }
+            enc = "o:" + flat.substring(0, flat.length-1);
+        }else{
+            enc = "s:" + v;
+        }
+        return escape(enc);
+    }
+});