/**
+ * @class Ext.state.Provider
+ * Abstract base class for state provider implementations. This class provides methods
+ * for encoding and decoding typed 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);
+ }
+});
+