JSVirtualMachine
JavaScript代码是在创建JSVirtualMachine类的虚拟机下执行,不能在两个不同JSVirtualMachine类之间进行数据传输,每个JSVirtualMachine类实例有自己的堆和垃圾回收器.JSContext
一个JSContext对象代表一个JavaScript代码执行环境,是一个全局对象,它在web开发中等同于一个window对象,同一个JSVirtualMachine类下不同的JSContext之间可以自由传值。-
JSValue
是一个主要的数据类型,能够代表任何可能的JavaScript的值,一个JSValue的实例绑定到它所在的JSContext对象中。
jscore01.png -
JSExport
一种协议提供了声明式的方法去向JavaScript代码导出Objective-C的实例类及其实例方法,类方法和属性
第一步请求JavaScript网络数据解析并转换为Objective-C中对象模型数组:jscore02.gif
//懒加载JSContext
-(JSContext *)context{
if (_context == nil) {
_context = [[JSContext alloc] init];
NSString *commonJSPath=[[NSBundle mainBundle] pathForResource:@"common" ofType:@"js"];
NSString *additionsJSPath=[[NSBundle mainBundle] pathForResource:@"additions" ofType:@"js"];
NSString *commomStr=[NSString stringWithContentsOfFile:commonJSPath encoding:NSUTF8StringEncoding error:nil];
NSString *additionsStr=[NSString stringWithContentsOfFile:additionsJSPath encoding:NSUTF8StringEncoding error:nil];
//将OC中的Movie类对象和JavaScript中的Movie对象桥接在一起
[_context setObject:[Movie self] forKeyedSubscript:@"Movie"];
//执行js代码
[_context evaluateScript:commomStr];
[_context evaluateScript:additionsStr];
}
return _context;
}
-(void)loadMoviesWith:(double)limit moviesBlock:(void(^)(NSArray *movies))moviesBlock
{
AFHTTPSessionManager *mgr=[AFHTTPSessionManager manager];
NSURLSessionDataTask *dataTask=[mgr GET:MovieURL parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
NSString *jsonString=[self switchObjectToJSON:responseObject];
//解析JSON数据并传出Movie模型数组
moviesBlock([self parseResponseObject:jsonString limit:limit]);
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
NSLog(@"MovieViewData Load Error %@",error);
}];
[dataTask resume];
}
//解析JSON数据
-(NSArray *)parseResponseObject:(NSString *)response limit:(double)limit{
//1
JSValue *parseFunction=[self.context objectForKeyedSubscript:@"parseJson"];
NSArray *parsed=[[parseFunction callWithArguments:@[response]] toArray];
//2
JSValue *filterFunction=[self.context objectForKeyedSubscript:@"filterByLimit"];
NSArray *filtered=[filterFunction callWithArguments:@[parsed,@(limit)]].toArray;
//3
return [self switchDictionaryArrayToModelArrayWith:filtered];
}
第二步自定义cell中数据设置:
-(void)setMovie:(Movie *)movie
{
_movie=movie;
_nameLabel.text=movie.title;
_priceLabel.text=movie.price;
[_imageView sd_setImageWithURL:[NSURL URLWithString:movie.imageUrl]];
}
第三部在控制器调用并加载数据:
-(NSArray *)movies
{
if (_movies == nil) {
_movies=[[NSArray alloc] init];
}
return _movies;
}
#pragma mark -- UITextFieldDelegate
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
//调用此方法 触发textFieldDidEndEditing:方法调用
[textField resignFirstResponder];
return YES;
}
-(void)textFieldDidEndEditing:(UITextField *)textField
{
double number=[textField.text doubleValue];
MovieViewData *mvData= [[MovieViewData alloc] init];
[mvData loadMoviesWith:number moviesBlock:^(NSArray *movies) {
self.movies=movies;
[self.collectionView reloadData];
}];
}
#pragma mark -- UICollectionViewDataSource
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return self.movies.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MovieViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:MovieViewCellID forIndexPath:indexPath];
cell.movie=self.movies[indexPath.row];
return cell;
}
jscore03.png
