Refactored constructor creation logic for new classes into its own method and placed both functions (and their shared var) into a closure to remove the 'extending' var from the module's scope
parent
095683ba42
commit
f632b93d64
131
lib/class.js
131
lib/class.js
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@ -81,77 +81,102 @@ function Class() {};
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/**
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* Set to TRUE when class is being extended to allow the instantiation of
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* abstract classes (for use in prototypes)
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* Creates extend function
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*
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* @var {boolean}
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* The 'extending' parameter is used to override the functionality of abstract
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* class constructors, allowing them to be instantiated for use in a subclass's
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* prototype.
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*
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* @param {boolean} extending whether a class is currently being extended
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*
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* @return {Function} extend function
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*/
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var extending = false;
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/**
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* Mimics class inheritance
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*
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* This method will mimic inheritance by setting up the prototype with the
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* provided base class (or, by default, Class) and copying the additional
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* properties atop of it.
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*
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* The class to inherit from (the first argument) is optional. If omitted, the
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* first argument will be considered to be the properties list.
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*
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* @return {Object} extended class
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*/
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function extend()
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var extend = ( function( extending )
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{
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// ensure we'll be permitted to instantiate abstract classes for the base
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extending = true;
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extending = false;
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var args = Array.prototype.slice.call( arguments ),
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props = args.pop() || {},
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base = args.pop() || Class,
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prototype = new base();
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/**
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* Mimics class inheritance
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*
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* This method will mimic inheritance by setting up the prototype with the
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* provided base class (or, by default, Class) and copying the additional
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* properties atop of it.
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*
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* The class to inherit from (the first argument) is optional. If omitted, the
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* first argument will be considered to be the properties list.
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*
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* @return {Object} extended class
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*/
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return function extend()
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{
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// ensure we'll be permitted to instantiate abstract classes for the base
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extending = true;
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// copy the given properties into the new prototype
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var result_data = {
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abstractMethods: ( base.abstractMethods || [] ).slice()
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};
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prop_copy( props, prototype, result_data );
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var args = Array.prototype.slice.call( arguments ),
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props = args.pop() || {},
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base = args.pop() || Class,
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prototype = new base();
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// reference to the parent prototype (for more experienced users)
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prototype.parent = base.prototype;
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// copy the given properties into the new prototype
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var result_data = {
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abstractMethods: ( base.abstractMethods || [] ).slice()
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};
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prop_copy( props, prototype, result_data );
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var new_class = ( result_data.abstractMethods.length === 0 )
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? (
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// concrete class
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function()
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// reference to the parent prototype (for more experienced users)
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prototype.parent = base.prototype;
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// set up the new class
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var new_class = create_ctor( result_data, extending );
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setup_props( new_class, result_data );
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new_class.prototype = prototype;
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new_class.constructor = new_class;
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// we're done with the extension process
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extending = false;
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return new_class;
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}
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/**
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* Creates the constructor for a new class
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*
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* This constructor will call the __constructor method for concrete classes
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* and throw an exception for abstract classes (to prevent instantiation).
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*
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* @param {Object} result_data data from property copy operation
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*
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* @return {Function} constructor
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*/
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function create_ctor( result_data )
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{
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// concrete class
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if ( result_data.abstractMethods.length === 0 )
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{
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return function()
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{
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if ( this.__construct instanceof Function )
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{
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// call the constructor
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this.__construct.apply( this, arguments );
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}
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}
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)
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: (
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// do not allow abstract classes to be instantiated
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function ()
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};
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}
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// abstract class
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else
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{
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return function ()
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{
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if ( !extending )
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{
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throw new Error( "Abstract classes cannot be instantiated" );
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}
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}
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);
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// set up the new class
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setup_props( new_class, result_data );
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new_class.prototype = prototype;
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new_class.constructor = new_class;
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// we're done with the extension process
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extending = false;
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return new_class;
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}
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};
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}
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}
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} )();
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/**
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