weex-code-analysis

Weex工作原理

二、知识准备 - Native <-> JavaScript Bridge

0. JSContext下标语法

JSContext[] Subscript语法

JSContext.mm源码 : JSContext Subscript Support

JSContext[@"nativeLog"] = ^(){};
//等价于
[JSContext globalObject][@"nativeLog"] = ^(){};

1. JS调用OC函数

1.1 ObjectiveC暴露函数给JavaScript

#import <JavaScriptCore/JavaScriptCore.h>

JSContext *jsContext = [[JSContext alloc] init];
// ObjectiveC Inject Block as JS Function
jsContext[@"nativeLog"] = ^() {
    NSMutableString *string = [NSMutableString string];
    [string appendString:@"jsLog: "];
    NSArray *args = [JSContext currentArguments];
    [args enumerateObjectsUsingBlock:^(JSValue *jsVal, NSUInteger idx, BOOL *stop) {
        [string appendFormat:@"%@ ", jsVal ];
    }];
    NSLog(@"%@", string);
};

1.2 JavaScript调用ObjectiveC函数

nativeLog("Hello from JS")
等价于
global.nativeLog("Hello from JS")

2. OC调用JS函数

2.1 JavaScript暴露函数给ObjectiveC

// JavaScript set global methods
global['callJS'] = (...args) => {
  receiveTasks(...args);
};

2.1 ObjectiveC调用JavaScript函数

#import <JavaScriptCore/JavaScriptCore.h>

JSContext *jsContext = [[JSContext alloc] init];
[[jsContext globalObject] invokeMethod:@"callJS" withArguments:@[execIns, tasks]];

OC和JS对象传递

OC和JS对象关系

参考文档：深入浅出 JavaScriptCore