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define("dojo/Stateful", ["./_base/declare", "./_base/lang", "./_base/array", "dojo/when"], function(declare, lang, array, when){
// module:
// dojo/Stateful
return declare("dojo.Stateful", null, {
// summary:
// Base class for objects that provide named properties with optional getter/setter
// control and the ability to watch for property changes
//
// The class also provides the functionality to auto-magically manage getters
// and setters for object attributes/properties.
//
// Getters and Setters should follow the format of _xxxGetter or _xxxSetter where
// the xxx is a name of the attribute to handle. So an attribute of "foo"
// would have a custom getter of _fooGetter and a custom setter of _fooSetter.
//
// example:
// | var obj = new dojo.Stateful();
// | obj.watch("foo", function(){
// | console.log("foo changed to " + this.get("foo"));
// | });
// | obj.set("foo","bar");
// _attrPairNames: Hash
// Used across all instances a hash to cache attribute names and their getter
// and setter names.
_attrPairNames: {},
_getAttrNames: function(name){
// summary:
// Helper function for get() and set().
// Caches attribute name values so we don't do the string ops every time.
// tags:
// private
var apn = this._attrPairNames;
if(apn[name]){ return apn[name]; }
return (apn[name] = {
s: "_" + name + "Setter",
g: "_" + name + "Getter"
});
},
postscript: function(/*Object?*/ params){
// Automatic setting of params during construction
if (params){ this.set(params); }
},
_get: function(name, names){
// summary:
// Private function that does a get based off a hash of names
// names:
// Hash of names of custom attributes
return typeof this[names.g] === "function" ? this[names.g]() : this[name];
},
get: function(/*String*/name){
// summary:
// Get a property on a Stateful instance.
// name:
// The property to get.
// returns:
// The property value on this Stateful instance.
// description:
// Get a named property on a Stateful object. The property may
// potentially be retrieved via a getter method in subclasses. In the base class
// this just retrieves the object's property.
// For example:
// | stateful = new dojo.Stateful({foo: 3});
// | stateful.get("foo") // returns 3
// | stateful.foo // returns 3
return this._get(name, this._getAttrNames(name)); //Any
},
set: function(/*String*/name, /*Object*/value){
// summary:
// Set a property on a Stateful instance
// name:
// The property to set.
// value:
// The value to set in the property.
// returns:
// The function returns this dojo.Stateful instance.
// description:
// Sets named properties on a stateful object and notifies any watchers of
// the property. A programmatic setter may be defined in subclasses.
// For example:
// | stateful = new dojo.Stateful();
// | stateful.watch(function(name, oldValue, value){
// | // this will be called on the set below
// | }
// | stateful.set(foo, 5);
//
// set() may also be called with a hash of name/value pairs, ex:
// | myObj.set({
// | foo: "Howdy",
// | bar: 3
// | })
// This is equivalent to calling set(foo, "Howdy") and set(bar, 3)
// If an object is used, iterate through object
if(typeof name === "object"){
for(var x in name){
if(name.hasOwnProperty(x) && x !="_watchCallbacks"){
this.set(x, name[x]);
}
}
return this;
}
var names = this._getAttrNames(name),
oldValue = this._get(name, names),
setter = this[names.s],
result;
if(typeof setter === "function"){
// use the explicit setter
result = setter.apply(this, Array.prototype.slice.call(arguments, 1));
}else{
// no setter so set attribute directly
this[name] = value;
}
if(this._watchCallbacks){
var self = this;
// If setter returned a promise, wait for it to complete, otherwise call watches immediatly
when(result, function(){
self._watchCallbacks(name, oldValue, value);
});
}
return this; // dojo/Stateful
},
_changeAttrValue: function(name, value){
// summary:
// Internal helper for directly changing an attribute value.
//
// name: String
// The property to set.
// value: Mixed
// The value to set in the property.
//
// description:
// Directly change the value of an attribute on an object, bypassing any
// accessor setter. Also handles the calling of watch and emitting events.
// It is designed to be used by descendent class when there are two values
// of attributes that are linked, but calling .set() is not appropriate.
var oldValue = this.get(name);
this[name] = value;
if(this._watchCallbacks){
this._watchCallbacks(name, oldValue, value);
}
return this; // dojo/Stateful
},
watch: function(/*String?*/name, /*Function*/callback){
// summary:
// Watches a property for changes
// name:
// Indicates the property to watch. This is optional (the callback may be the
// only parameter), and if omitted, all the properties will be watched
// returns:
// An object handle for the watch. The unwatch method of this object
// can be used to discontinue watching this property:
// | var watchHandle = obj.watch("foo", callback);
// | watchHandle.unwatch(); // callback won't be called now
// callback:
// The function to execute when the property changes. This will be called after
// the property has been changed. The callback will be called with the |this|
// set to the instance, the first argument as the name of the property, the
// second argument as the old value and the third argument as the new value.
var callbacks = this._watchCallbacks;
if(!callbacks){
var self = this;
callbacks = this._watchCallbacks = function(name, oldValue, value, ignoreCatchall){
var notify = function(propertyCallbacks){
if(propertyCallbacks){
propertyCallbacks = propertyCallbacks.slice();
for(var i = 0, l = propertyCallbacks.length; i < l; i++){
propertyCallbacks[i].call(self, name, oldValue, value);
}
}
};
notify(callbacks['_' + name]);
if(!ignoreCatchall){
notify(callbacks["*"]); // the catch-all
}
}; // we use a function instead of an object so it will be ignored by JSON conversion
}
if(!callback && typeof name === "function"){
callback = name;
name = "*";
}else{
// prepend with dash to prevent name conflicts with function (like "name" property)
name = '_' + name;
}
var propertyCallbacks = callbacks[name];
if(typeof propertyCallbacks !== "object"){
propertyCallbacks = callbacks[name] = [];
}
propertyCallbacks.push(callback);
// TODO: Remove unwatch in 2.0
var handle = {};
handle.unwatch = handle.remove = function(){
var index = array.indexOf(propertyCallbacks, callback);
if(index > -1){
propertyCallbacks.splice(index, 1);
}
};
return handle; //Object
}
});
});
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