/**
* Provides Attribute configurations.
* @namespace YAHOO.util
* @class Attribute
* @constructor
* @param hash {Object} The intial Attribute.
* @param {YAHOO.util.AttributeProvider} The owner of the Attribute instance.
*/
YAHOO.util.Attribute = function(hash, owner) {
if (owner) {
this.owner = owner;
this.configure(hash, true);
}
};
YAHOO.util.Attribute.prototype = {
/**
* The name of the attribute.
* @property name
* @type String
*/
name: undefined,
/**
* The value of the attribute.
* @property value
* @type String
*/
value: null,
/**
* The owner of the attribute.
* @property owner
* @type YAHOO.util.AttributeProvider
*/
owner: null,
/**
* Whether or not the attribute is read only.
* @property readOnly
* @type Boolean
*/
readOnly: false,
/**
* Whether or not the attribute can only be written once.
* @property writeOnce
* @type Boolean
*/
writeOnce: false,
/**
* The attribute's initial configuration.
* @private
* @property _initialConfig
* @type Object
*/
_initialConfig: null,
/**
* Whether or not the attribute's value has been set.
* @private
* @property _written
* @type Boolean
*/
_written: false,
/**
* The method to use when setting the attribute's value.
* The method recieves the new value as the only argument.
* @property method
* @type Function
*/
method: null,
/**
* The validator to use when setting the attribute's value.
* @property validator
* @type Function
* @return Boolean
*/
validator: null,
/**
* Retrieves the current value of the attribute.
* @method getValue
* @return {any} The current value of the attribute.
*/
getValue: function() {
return this.value;
},
/**
* Sets the value of the attribute and fires beforeChange and change events.
* @method setValue
* @param {Any} value The value to apply to the attribute.
* @param {Boolean} silent If true the change events will not be fired.
* @return {Boolean} Whether or not the value was set.
*/
setValue: function(value, silent) {
var beforeRetVal;
var owner = this.owner;
var name = this.name;
var event = {
type: name,
prevValue: this.getValue(),
newValue: value
};
if (this.readOnly || ( this.writeOnce && this._written) ) {
return false; // write not allowed
}
if (this.validator && !this.validator.call(owner, value) ) {
return false; // invalid value
}
if (!silent) {
beforeRetVal = owner.fireBeforeChangeEvent(event);
if (beforeRetVal === false) {
YAHOO.log('setValue ' + name +
'cancelled by beforeChange event', 'info', 'Attribute');
return false;
}
}
if (this.method) {
this.method.call(owner, value);
}
this.value = value;
this._written = true;
event.type = name;
if (!silent) {
this.owner.fireChangeEvent(event);
}
return true;
},
/**
* Allows for configuring the Attribute's properties.
* @method configure
* @param {Object} map A key-value map of Attribute properties.
* @param {Boolean} init Whether or not this should become the initial config.
*/
configure: function(map, init) {
map = map || {};
this._written = false; // reset writeOnce
this._initialConfig = this._initialConfig || {};
for (var key in map) {
if ( key && map.hasOwnProperty(key) ) {
this[key] = map[key];
if (init) {
this._initialConfig[key] = map[key];
}
}
}
},
/**
* Resets the value to the initial config value.
* @method resetValue
* @return {Boolean} Whether or not the value was set.
*/
resetValue: function() {
return this.setValue(this._initialConfig.value);
},
/**
* Resets the attribute config to the initial config state.
* @method resetConfig
*/
resetConfig: function() {
this.configure(this._initialConfig);
},
/**
* Resets the value to the current value.
* Useful when values may have gotten out of sync with actual properties.
* @method refresh
* @return {Boolean} Whether or not the value was set.
*/
refresh: function(silent) {
this.setValue(this.value, silent);
}
};