JSPatch

JSPatch

 

 



JSPatch bridge Objective-C and JavaScript using the Objective-C runtime. You can call any Objective-C class and method in JavaScript by just including a small engine. That makes the APP obtain the power of script language: add modules or replacing Objective-C
codes to fix bugs dynamically.

JSPatch is still in development, welcome to improve the project together.

Example

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[JPEngine startEngine];
NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"demo" ofType:@"js"];
NSString *script = [NSString stringWithContentsOfFile:sourcePath encoding:NSUTF8StringEncoding error:nil];
[JPEngine evaluateScript:script];

self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
[self.window addSubview:[self genView]];
[self.window makeKeyAndVisible];

return YES;
}

- (UIView *)genView
{
return [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 320)];
}

@end

// demo.js
require('UIView, UIColor, UILabel')
defineClass('AppDelegate', {
// replace the -genView method
genView: function() {
var view = self.ORIGgenView();
view.setBackgroundColor(UIColor.greenColor())
var label = UILabel.alloc().initWithFrame(view.frame());
label.setText("JSPatch");
label.setTextAlignment(1);
view.addSubview(label);
return view;
}
});

Installation

CocoaPods

CocoaPods is a dependency manager for Objective-C, which automates and simplifies the process of using 3rd-party libraries
like JSPatch in your projects. See the "Getting Started" guide for more information.

# Your Podfile
platform :ios, '7.0'
pod 'JSPatch', '~> 0.0.1'

Manually

Copy 

JSEngine.m

 

JSEngine.h

 

JSPatch.js

 in 

JSPatch/

 to
your project.

Usage

Objective-C

#import "JPEngine.h"

call 

[JPEngine startEngine]

exec JavasScript by 

[JPEngine evaluateScript:@""]

[JPEngine startEngine];

// exec js directly
[JPEngine evaluateScript:@"\
var alertView = require('UIAlertView').alloc().init();\
alertView.setTitle('Alert');\
alertView.setMessage('AlertView from js'); \
alertView.addButtonWithTitle('OK');\
alertView.show(); \
"];

// exec js file from network
[NSURLConnection sendAsynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://cnbang.net/test.js"]] queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
NSString *script = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
[JPEngine evaluateScript:script];
}];

// exec local js file
NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"sample" ofType:@"js"];
NSString *script = [NSString stringWithContentsOfFile:sourcePath encoding:NSUTF8StringEncoding error:nil];
[JPEngine evaluateScript:script];

JavaScript

1.
require

Call 

require('className')

 before using the Objective-C class. You can use 

,

 to
separate multiple class to import them at one time.

require('UIView, UIColor')
var view = UIView.alloc().init()
var red = UIColor.redColor()
var ctrl = require('UIViewController').alloc().init()

2.
Invoking method

require('UIView, UIColor, UISlider, NSIndexPath')

// Invoke class method
var redColor = UIColor.redColor();

// Invoke instance method
var view = UIView.alloc().init();
view.setNeedsLayout();

// set proerty
view.setBackgroundColor(redColor);

// get property
var bgColor = view.backgroundColor();

// multi-params method (use underline to separate)
// OC：NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:1];
var indexPath = NSIndexPath.indexPathForRow_inSection(0, 1);

// method name contains underline (use double undeline to represent)
// OC: [JPObject _privateMethod];
JPObject.__privateMethod()

3.
defineClass

You can define a new Objective-C class in JavaScript:

defineClass("JPViewController: UIViewController", {
//instance method definitions
viewDidLoad: function() {
//use self.super to call super method
self.super.viewDidLoad()

//do something here
},

viewDidAppear: function(animated) {

}
}, {
//class method definitions
description: function() {
return "I'm JPViewController"
}
})

Or you can redefine an exists class and override methods.

// OC
@implementation JPTableViewController
...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *content = self.dataSource[[indexPath row]];  //may cause out of bound
JPViewController *ctrl = [[JPViewController alloc] initWithContent:content];
[self.navigationController pushViewController:ctrl];
}
- (NSArray *)dataSource
{
return @[@"JSPatch", @"is"];
}
- (void)customMethod
{
NSLog(@"callCustom method")
}
@end

// JS
defineClass("JPTableViewController", {
// instance method definitions
tableView_didSelectRowAtIndexPath: function(tableView, indexPath) {
var row = indexPath.row()
if (self.dataSource().length > row) {  //fix the out of bound bug here
var content = self.dataSource()[row];
var ctrl = JPViewController.alloc().initWithContent(content);
self.navigationController().pushViewController(ctrl);
}
},

dataSource: function() {
// get the original method by adding prefix 'ORIG'
var data = self.ORIGdataSource();
return data.push('Good!');
}
}, {})

4.
CGRect / CGPoint / CGSize / NSRange

Use hashes:

// OC
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
CGFloat x = view.frame.origin.x;

// JS
var view = UIView.alloc().initWithFrame({x:20, y:20, width:100, height:100});
var x = view.bounds.x;

5.
block

You should indicate each type of params when passing block from js to objc.

// OC
@implementation JPObject
+ (void)request:(void(^)(NSString *content, BOOL success))callback
{
callback(@"I'm content", YES);
}
@end

// JS
require('JPObject').request(block("NSString *, BOOL", function(ctn, succ) {
if (succ) log(ctn)  //output: I'm content
}));

Just call directly when the block passing from objc to js:

// OC
@implementation JPObject
typedef void (^JSBlock)(NSDictionary *dict);
+ (JSBlock)genBlock
{
NSString *ctn = @"JSPatch";
JSBlock block = ^(NSDictionary *dict) {
NSLog(@"I'm %@, version: %@", ctn, dict[@"v"])
};
return block;
}
@end

// JS
var blk = require('JPObject').genBlock();
blk({v: "0.0.1"});  //output: I'm JSPatch, version: 0.0.1

6.
dispatch

Using 

dispatch_after()

 

dispatch_async_main()

 

dispatch_sync_main()

dispatch_async_global_queue()

 to
call GCD.

// OC
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// do something
});

dispatch_async(dispatch_get_main_queue(), ^{
// do something
});

// JS
dispatch_after(function(1.0, function(){
// do something
}))
dispatch_async_main(function(){
// do something
})