NodObjC
The Node.js ⇆ Objective-C bridge
NodObjC exposes the Objective-C runtime to Node.js in a high-level, easy
to use fashion. It uses the BridgeSupport files to dynamically generate an
API from an Objective-C "Framework", and uses the node ffi module to dynamically interact
with the Objective-C runtime.
Essentially, NodObjC is similar in nature to the other popular Objective-C
scripting bridges:
So you can write entire Cocoa or iOS GUI applications entirely in Node.js
JavaScript! Applications are interpreted at runtime through the V8 engine,
rather than (pre)compiled to a (binary) machine exectuable. This has the advantage of being
able to tweak code without having to recompile; excellent for rapid prototyping
and development (or for those GUI applications where absolute speed is not a
requirement, i.e. most). So what are you waiting for? Get to coding!
Installation
Install using npm, of course!
$ npm install nodobjc
Or add it to the "dependencies" section of your package.json file.
Hello World
var $ = require('nodobjc')
// First you import the "Foundation" framework
$.framework('Foundation')
// Setup the recommended NSAutoreleasePool instance
var pool = $.NSAutoreleasePool('alloc')('init')
// NSStrings and JavaScript Strings are distinct objects, you must create an
// NSString from a JS String when an Objective-C class method requires one.
var string = $.NSString('stringWithUTF8String', 'Hello Objective-C World!')
// Print out the contents (toString() ends up calling [string description])
console.log(string)
// → Prints "Hello Objective-C World!"
pool('drain')
Be sure to check out the full API docs.
Introduction
This module offers a bi-directional bridge between Node.js and the Objective-C
runtime. What does that mean exactly? Well due to the design of the Objective-C
runtime, it is possible to port the entire API to other languages. There are
quite a few bridges for Obj-C so one for node was a necessity.
So with this module, you get access to all of the Objective-C APIs, but you
invoke them through JavaScript. Obj-C has a concept of "message passing" to
invoke methods on objects. The way that you pass messages around is probably a
little bit different than the kind of JavaScript you're used to:
// In JavaScript, you invoke a function on an object like:
obj.func(arg)
Compared to:
// In NodObjC, you send a message to an object like:
obj('func', arg)
In Objective-C, the names of methods are part of the arguments that you pass
along:
[array insertObject: obj
atIndex: 5]
The equivalent of the above message invocation in NodObjC syntax would be:
array('insertObject', obj,
'atIndex', 5)
So the even numbered arguments are the parts of the method name that will be
invoked, and the odd numbered arguments are the Obj-C arguments themselves. In
the above example, the insertObject:atIndex: function will be invoked.
In NodObjC, not only is the Objective-C runtime exposed, but so are the
corresponding C functions that usually go along with these APIs (thanks to
BridgeSupport). So for example, we can make an NSRect by calling the
NSMakeRect() C function:
$.NSMakeRect(5, 10, 8, 30)
// -> NSRect struct
There's a plethora of other Objective-C resources and tutorials out there.
You should definitely have Apple's official Mac or iOS API
docs handy at all times.
Support / Getting Involved
If you're looking for support for developing with/for NodObjC you might want
to join the mailing list, and check out the #nodobjc channel
in the Freenode IRC server.
Additional topics of discussion can be found on the Wiki page.