JavaScriptCore框架使用——JSExport及内存管理

@protocol PersonProtocol <JSExport>

@property (nonatomic, strong) NSDictionary *urls;
- (NSString *)fullName;

@end

- (void)jsTest8 {
    JSContext *context = [[JSContext alloc] init];
    context.exceptionHandler = ^(JSContext *con, JSValue *exception) {
        NSLog(@"JSValue exception: %@", exception);
        con.exception = exception;
    };
    
    context[@"log"] = ^() {
        NSArray *args = [JSContext currentArguments];
        for (id obj in args) {
            NSLog(@"js log: %@", obj);
        }
    };
    
    Person *person = [[Person alloc] init];
    context[@"p"] = person;
    person.firstName = @"Tony";
    person.lastName = @"Han";
    person.urls = @{@"site": @"http://www.ibloodline.com"};
    
    // ok to get fullName
    [context evaluateScript:@"log(p.fullName());"];
    // cannot access firstName
    [context evaluateScript:@"log(p.firstName);"];
    // ok to access dictionary as object
    [context evaluateScript:@"log('site:', p.urls.site, 'blog:', p.urls.blog);"];
    // ok to change urls property
    [context evaluateScript:@"p.urls = {blog:'http://blog.ibloodline.com'}"];
    [context evaluateScript:@"log('-------')"];
    [context evaluateScript:@"log('site:', p.urls.site, 'blog:', p.urls.blog);"];
    
    // affect on Objective-C side as well
    NSLog(@"%@", person.urls);
}

@protocol MultiArgs <JSExport>
- (void)doFoo:(id)foo withBar:(id)bar;
@end

@protocol LongArgs <JSExport>
 
JSExportAs(testArgumentTypes,
           - (NSString *)testArgumentTypesWithInt:(int)i double:(double)d 
                    boolean:(BOOL)b string:(NSString *)s number:(NSNumber *)n 
                    array:(NSArray *)a dictionary:(NSDictionary *)o
           );
 
@end

@protocol JSUITextFieldExport <JSExport>
 
@property(nonatomic,copy) NSString *text;
 
@end

- (void)viewDidLoad {
    [super viewDidLoad];
    
    class_addProtocol([UITextField class], @protocol(JSUITextFieldExport));
}

- (IBAction)buttonClicked {
    JSContext *context = [[JSContext alloc] init];
    context[@"log"] = ^() {
        NSLog(@"---Begin Log---");
        NSArray *args = [JSContext currentArguments];
        for (JSValue *jsVal in args) {
            NSLog(@"%@", jsVal);
        }
        NSLog(@"---End Log---");
    };
    
    context[@"textField"] = self.textField;
    NSString *script = @"var text = textField.text;";
    [context evaluateScript:script];
    
    [context evaluateScript:@"log(text)"];
    
    NSString *script2 = @"var num = parseInt(textField.text, 10);"
    "++num;"
    "textField.text = num;";
    [context evaluateScript:script2];
}

@interface JSManagedValue : NSObject
 
// Convenience method for creating JSManagedValues from JSValues.
+ (JSManagedValue *)managedValueWithValue:(JSValue *)value;
 
// Create a JSManagedValue.
- (id)initWithValue:(JSValue *)value;
 
// Get the JSValue to which this JSManagedValue refers. If the JavaScript value has been collected,
// this method returns nil.
- (JSValue *)value;
 
@end

@interface JSVirtualMachine : NSObject
 
// Create a new JSVirtualMachine.
- (id)init;
 
// addManagedReference:withOwner and removeManagedReference:withOwner allow 
// clients of JSVirtualMachine to make the JavaScript runtime aware of 
// arbitrary external Objective-C object graphs. The runtime can then use 
// this information to retain any JavaScript values that are referenced 
// from somewhere in said object graph.
// 
// For correct behavior clients must make their external object graphs 
// reachable from within the JavaScript runtime. If an Objective-C object is 
// reachable from within the JavaScript runtime, all managed references 
// transitively reachable from it as recorded with 
// addManagedReference:withOwner: will be scanned by the garbage collector.
// 
- (void)addManagedReference:(id)object withOwner:(id)owner;
- (void)removeManagedReference:(id)object withOwner:(id)owner;
 
@end