在完成这个想法之后,我想到了更多。
当应用程序安装时,我将包中的默认数据文件复制到Documents文件夹。当应用程序运行didFinishLaunchingWithOptions
我叫下面的方法:
- (void)writeJsonToFile
{
//applications Documents dirctory path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//live json data url
NSString *stringURL = @"http://path-to-live-file.json";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
//attempt to download live data
if (urlData)
{
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"data.json"];
[urlData writeToFile:filePath atomically:YES];
}
//copy data from initial package into the applications Documents folder
else
{
//file to write to
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"data.json"];
//file to copy from
NSString *json = [ [NSBundle mainBundle] pathForResource:@"data" ofType:@"json" inDirectory:@"html/data" ];
NSData *jsonData = [NSData dataWithContentsOfFile:json options:kNilOptions error:nil];
//write file to device
[jsonData writeToFile:filePath atomically:YES];
}
}
然后在整个当我需要引用数据的应用程序,我用的是保存的文件。
//application Documents dirctory path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSError *jsonError = nil;
NSString *jsonFilePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"data.json"];
NSData *jsonData = [NSData dataWithContentsOfFile:jsonFilePath options:kNilOptions error:&jsonError ];
要引用JSON文件在我的JS代码,我增加了一个URL参数“SRC”,并通过文件路径到应用程序文件夹。
request.open('GET', src, false);