mediawiki-extensions-Visual.../modules/ve/ve.Factory.js
Trevor Parscal 6c3878be9e Added multiple name registration to ve.Factory
Also changed from using "type" to "name" to make it less specific and added a test to make sure it's working.

Change-Id: I150a7ab1a57b3df85b459dbc411c2eaefe08b5bb
2012-10-12 17:43:04 -07:00

101 lines
2.8 KiB
JavaScript

/**
* VisualEditor Factory class.
*
* @copyright 2011-2012 VisualEditor Team and others; see AUTHORS.txt
* @license The MIT License (MIT); see LICENSE.txt
*/
/**
* Generic object factory.
*
* @class
* @abstract
* @constructor
* @extends {ve.EventEmitter}
*/
ve.Factory = function VeFactory() {
// Parent constructor
ve.EventEmitter.call( this );
// Properties
this.registry = [];
};
/* Inheritance */
ve.inheritClass( ve.Factory, ve.EventEmitter );
/* Methods */
/**
* Register a constructor with the factory.
*
* Arguments will be passed through directly to the constructor.
* @see {ve.Factory.prototype.create}
*
* @method
* @param {String|String[]} name Symbolic name or list of symbolic names
* @param {Function} constructor Constructor to use when creating object
* @throws 'Constructor must be a function, cannot be a string'
*/
ve.Factory.prototype.register = function ( name, constructor ) {
var i, len;
if ( typeof constructor !== 'function' ) {
throw new Error( 'Constructor must be a function, cannot be a ' + typeof constructor );
}
if ( ve.isArray( name ) ) {
for ( i = 0, len = name.length; i < len; i++ ) {
this.register( name[i], constructor );
}
} else if ( typeof name === 'string' ) {
this.registry[name] = constructor;
this.emit( 'register', name, constructor );
} else {
throw new Error( 'Name must be a string or array of strings, cannot be a ' + typeof name );
}
};
/**
* Create an object based on a name.
*
* Name is used to look up the constructor to use, while all additional arguments are passed to the
* constructor directly, so leaving one out will pass an undefined to the constructor.
*
* @method
* @param {string} name Object name.
* @param {mixed} [...] Arguments to pass to the constructor.
* @returns {Object} The new object.
* @throws 'Unknown object name'
*/
ve.Factory.prototype.create = function ( name ) {
var args, obj,
constructor = this.registry[name];
if ( constructor === undefined ) {
throw new Error( 'Unknown object name: ' + name );
}
// Convert arguments to array and shift the first argument (name) off
args = Array.prototype.slice.call( arguments, 1 );
// We can't use the "new" operator with .apply directly because apply needs a
// context. So instead just do what "new" does: create an object that inherits from
// the constructor's prototype (which also makes it an "instanceof" the constructor),
// then invoke the constructor with the object as context, and return it (ignoring
// the constructor's return value).
obj = ve.createObject( constructor.prototype );
constructor.apply( obj, args );
return obj;
};
/**
* Gets a constructor for a given name.
*
* @method
* @param {String} name Object name
* @returns {Function|undefined} Constructor for name
*/
ve.Factory.prototype.lookup = function ( name ) {
return this.registry[name];
};