wax: A C repository from windgo

Wax is being maintained by Alibaba

Thanks to @probablycorey for creating such a greate project. Wax is the best bridge between Lua and Objective-C, we will be maintaining it here. We have fixed a lot of issues such as 64-bit support and thread-safety. We have also added many features such as converting Lua functions to OC blocks, calling OC blocks in Lua, getting/setting private ivars, built-in commonly used C functions, and even Lua code debugging.

Wax

Wax is a framework that lets you write native iPhone apps in Lua. It bridges Objective-C and Lua using the Objective-C runtime. With Wax, anything you can do in Objective-C is automatically available in Lua! What are you waiting for, give it a shot!

Why write iPhone apps in Lua?

I love writing iPhone apps, but would rather write them in a dynamic language than in Objective-C. Here are some reasons why many people prefer Lua + Wax over Objective-C...

Automatic Garbage Collection! Gone are the days of alloc, retain, and release.
Less Code! No more header files, no more static types, array and dictionary literals! Lua enables you to get more power out of less lines of code.
Access to every Cocoa, UITouch, Foundation, etc.. framework, if it's written in Objective-C, Wax exposes it to Lua automatically. All the frameworks you love are all available to you!
Super easy HTTP requests. Interacting with a REST webservice has never been eaiser
Lua has closures, also known as blocks! Anyone who has used these before knows how powerful they can be.
Lua has a build in Regex-like pattern matching library.

Examples

For some simple Wax apps, check out the examples folder.

How would I create a UIView and color it red?

-- forget about using alloc! Memory is automatically managed by Wax
view = UIView:initWithFrame(CGRect(0, 0, 320, 100))

-- use a colon when sending a message to an Objective-C Object
-- all methods available to a UIView object can be accessed this way
view:setBackgroundColor(UIColor:redColor())

What about methods with multiple arguments?

-- Just add underscores to the method name, then write the arguments like
-- you would in a regular C function
UIApplication:sharedApplication():setStatusBarHidden_animated(true, false)

How do I send an array/string/dictionary

-- Wax automatically converts array/string/dictionary objects to NSArray,
-- NSString and NSDictionary objects (and vice-versa)
images = {"myFace.png", "yourFace.png", "theirFace.png"}
imageView = UIImageView:initWithFrame(CGRect(0, 0, 320, 460))
imageView:setAnimationImages(images)

What if I want to create a custom UIViewController?

-- Created in "MyController.lua"
--
-- Creates an Objective-C class called MyController with UIViewController
-- as the parent. This is a real Objective-C object, you could even
-- reference it from Objective-C code if you wanted to.
waxClass{"MyController", UIViewController}

function init()
  -- to call a method on super, simply use self.super
  self.super:initWithNibName_bundle("MyControllerView.xib", nil)
  return self
end

function viewDidLoad()
  -- Do all your other stuff here
end

You said HTTP calls were easy, I don't believe you...

url = "http://search.twitter.com/trends/current.json"

-- Makes an asyncronous call, the callback function is called when a
-- response is received
wax.http.request{url, callback = function(body, response)
  -- request is just a NSHTTPURLResponse
  puts(response:statusCode())

  -- Since the content-type is json, Wax automatically parses it and places
  -- it into a Lua table
  puts(body)
end}

Since Wax converts NSString, NSArray, NSDictionary and NSNumber to native Lua values, you have to force objects back to Objective-C sometimes. Here is an example.

local testString = "Hello lua!"
local bigFont = UIFont:boldSystemFontOfSize(30)
local size = toobjc(testString):sizeWithFont(bigFont)
puts(size)

How do I convert Lua functions to Objective-C blocks? see more detail.

UIView:animateWithDuration_animations_completion(1, 
    toblock(
        function()
            label:setCenter(CGPoint(300, 300))
        end
    ),
    toblock(
             function(finished)
                print('lua animations completion ' .. tostring(finished))
            end
    ,{"void", "BOOL"})
)

---OC method is -(void)testReturnIdWithFirstIdBlock:(id(^)(id aFirstId, BOOL aBOOL, int aInt, NSInteger aInteger, float aFloat, CGFloat aCGFloat, id aId))block
self:testReturnIdWithFirstIdBlock(
toblock(
    function(aFirstId, aBOOL, aInt, aInteger, aFloat, aCGFloat, aId)
        print("aFirstId=" .. tostring(aFirstId))
        -- assert(aFirstId == self, "aFirstInt不等")
        assertResult(self, aBOOL, aInt, aInteger, aFloat, aCGFloat, aId)
        print("LUA TEST SUCCESS: testReturnIdWithFirstIdBlock")
        return aFirstId
    end
    , {"id","id", "BOOL", "int", "NSInteger", "float", "CGFloat", "id"})
)

What about calling Objective-C blocks?

--OC block type is id (^)(NSInteger, id, BOOL, CGFloat)
local res = luaCallBlock(block, 123456, aObject, true, 123.456);

--or you can call like this:
local res = luaCallBlockWithParamsTypeArray(block, {"id","NSInteger", "id", "BOOL", "CGFloat"},  123456, aObject, true, 123.456);

What if my instance variables are privately implemented?

print(self:view():getIvarInt("_countOfMotionEffectsInSubtree"))

self:setIvar_withObject("_title", "abcdefg")
print(self:getIvarObject("_title"))

self:setIvar_withObject("_infoDict", {k11="v11", k22="v22"})
print(toobjc(self:getIvarObject("_infoDict")))

You want to call some C functions?

luaSetWaxConfig({openBindOCFunction=true})--bind built-in C function

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), 
        toblock(
            function( )
                print(string.format("dispatch_async"));
            end)
    );

UIGraphicsBeginImageContext(CGSize(200,400));
UIApplication:sharedApplication():keyWindow():layer():renderInContext(UIGraphicsGetCurrentContext());
local aImage =UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

local imageData =UIImagePNGRepresentation(aImage);
print("imageData.length=", imageData.length);
local image = aImage;
local data = UIImageJPEGRepresentation(image, 0.8);
print("data.length=", data:length());

Lua code debug

Any way to debug my Lua code?
Ofcourse, you can use the powerfull ZeroBraneStudio to debug. see more detail.

Watch OS

Can Wax run on watch OS? Thanks to the cross platform characteristics of Lua, Wax can run on watch OS certainly. see tools/WaxWatchFramework and examples/WaxWatchExample

Use with cocoapods

see demo in examples/InstallationExample/InstallWithCocoaPods .

add pod 'wax', :git=>'https://github.com/alibaba/wax.git', :tag=>'1.1.0' to your podfile. (tag in your needs)
then you can run lua code.

wax_start(nil, nil);
wax_runLuaString("print('hello wax')");

Setup & Tutorials

Setting up Wax

How does Wax work?

Simple Twitter client in Wax

Which API's are included?

They all are! I can't stress this enough, anything that is written in Objective-C (even external frameworks) will work automatically in Wax! UIAcceleration works like UIAcceleration, MapKit works like MapKit, GameKit works like GameKit, Snozberries taste like Snozberries!

Created By

Corey Johnson (probablycorey at gmail dot com)

Feature Requests? Bugs? - Issue tracking and release planning.
Mailing List
Quick questions or issues? Send an email to @Zhengwei Yin (Junzhan)
Communicate in gitter: https://gitter.im/alibaba/wax
Communicate in QQ group: 196306834

Contribute

@Zhengwei Yin (Junzhan)
Fork it, change it, commit it, push it, send pull request; instant glory!

windgo/wax