/* * Copyright (C) 2013 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #import #if JSC_OBJC_API_ENABLED /*! @protocol @abstract JSExport provides a declarative way to export Objective-C objects and classes -- including properties, instance methods, class methods, and initializers -- to JavaScript. @discussion When an Objective-C object is exported to JavaScript, a JavaScript wrapper object is created. In JavaScript, inheritance works via a chain of prototype objects. For each Objective-C class in each JSContext, an object appropriate for use as a prototype will be provided. For the class NSObject the prototype will be the Object prototype. For all other Objective-C classes a prototype will be created. The prototype for a given Objective-C class will have its internal [Prototype] property set to point to the prototype created for the Objective-C class's superclass. As such the prototype chain for a JavaScript wrapper object will reflect the wrapped Objective-C type's inheritance hierarchy. JavaScriptCore also produces a constructor for each Objective-C class. The constructor has a property named 'prototype' that references the prototype, and the prototype has a property named 'constructor' that references the constructor. By default JavaScriptCore does not export any methods or properties from an Objective-C class to JavaScript; however methods and properties may be exported explicitly using JSExport. For each protocol that a class conforms to, if the protocol incorporates the protocol JSExport, JavaScriptCore exports the methods and properties in that protocol to JavaScript For each exported instance method JavaScriptCore will assign a corresponding JavaScript function to the prototype. For each exported Objective-C property JavaScriptCore will assign a corresponding JavaScript accessor to the prototype. For each exported class method JavaScriptCore will assign a corresponding JavaScript function to the constructor. For example:

@textblock
    @protocol MyClassJavaScriptMethods 
    - (void)foo;
    @end

    @interface MyClass : NSObject 
    - (void)foo;
    - (void)bar;
    @end
@/textblock

Data properties that are created on the prototype or constructor objects have the attributes: writable:true, enumerable:false, configurable:true. Accessor properties have the attributes: enumerable:false and configurable:true. If an instance of MyClass is converted to a JavaScript value, the resulting wrapper object will (via its prototype) export the method foo to JavaScript, since the class conforms to the MyClassJavaScriptMethods protocol, and this protocol incorporates JSExport. bar will not be exported. JSExport supports properties, arguments, and return values of the following types: Primitive numbers: signed values up to 32-bits convert using JSValue's valueWithInt32/toInt32. Unsigned values up to 32-bits convert using JSValue's valueWithUInt32/toUInt32. All other numeric values convert using JSValue's valueWithDouble/toDouble. BOOL: values convert using JSValue's valueWithBool/toBool. id: values convert using JSValue's valueWithObject/toObject. Objective-C instance pointers: Pointers convert using JSValue's valueWithObjectOfClass/toObject. C structs: C structs for CGPoint, NSRange, CGRect, and CGSize convert using JSValue's appropriate methods. Other C structs are not supported. Blocks: Blocks convert using JSValue's valueWithObject/toObject. All objects that conform to JSExport convert to JavaScript wrapper objects, even if they subclass classes that would otherwise behave differently. For example, if a subclass of NSString conforms to JSExport, it converts to JavaScript as a wrapper object rather than a JavaScript string. */ @protocol JSExport @end /*! @define @abstract Rename a selector when it's exported to JavaScript. @discussion When a selector that takes one or more arguments is converted to a JavaScript property name, by default a property name will be generated by performing the following conversion: - All colons are removed from the selector - Any lowercase letter that had followed a colon will be capitalized. Under the default conversion a selector doFoo:withBar: will be exported as doFooWithBar. The default conversion may be overridden using the JSExportAs macro, for example to export a method doFoo:withBar: as doFoo:

@textblock
    @protocol MyClassJavaScriptMethods 
    JSExportAs(doFoo,
    - (void)doFoo:(id)foo withBar:(id)bar
    );
    @end
@/textblock

Note that the JSExport macro may only be applied to a selector that takes one or more argument. */ #define JSExportAs(PropertyName, Selector) \ @optional Selector __JS_EXPORT_AS__##PropertyName:(id)argument; @required Selector #endif