cocoascript-class

cocoascript-class

Lets you create real ObjC classes in cocoascript so you can implement delegates, subclass builtin types, etc

Installation

In your plugin, assuming you're already using an ES6 build toolchain and either npm or yarn

npm install --save cocoascript-class or yarn add cocoascript-class

Usage

Here is an example class created with this:

const MyClass = new ObjCClass({
  // String values create ivar
  _private: 'initial',
  
  // This is a method on the class.
  test() {
    log("test: " + this._private);
  },
});

// MyClass is now a real ObjC class as far as cocoascript is concerned:
const obj = MyClass.new();

// You can use setters for the ivars
obj._private = "efgh";

// And call methods
[obj test];
obj.test();

Advanced

Calling super

The SuperCall function will let you send a message to your superclass, equivalent to [super myMethod]. However, you need to tell it the types of the arguments to your function.

SuperCall(sel, argumentTypes, returnType);

each argument or return type is just an object with {type: encodedString}, where encodedString is the Objective-C type encoding of that type, for example:

@encode(char*) = "*"
@encode(id) = "@" // any object can use this encoding
@encode(Class) = "#"
@encode(void*) = "^v"
@encode(CGRect) = "{CGRect={CGPoint=dd}{CGSize=dd}}"
@encode(SEL) = ":"

Here, we call [super description] in our class' description method:

import ObjCClass, {SuperCall} from 'cocoascript-class';

const HasDescriptionClass = new ObjCClass({  
  description() {
    // You should cache the result of SuperCall function, don't look it up each time
    if (typeof MyClass._superDesc == 'undefined') {
      const sel = NSStringFromSelector('description');
      MyClass._superDesc = SuperCall(sel, [], {type:"@"});
    }
    const superDesc = MyClass._superDesc.call(this);
    return NSString.stringWithString(`${superDesc} { _private=${this._private} }`);
  }
});

// MyClass is now a real ObjC class as far as cocoascript is concerned:
const obj = HasDescriptionClass.new();
log(obj); // calls description to become a string