在iOS中检索和写入文件

Question

I looked at many SO question where the user wanted to access a document in his app directory. I am new to all of this and just want some clarification on the matter. I am building an open-source content blocker for iOS 9.

You can see the file tree. I wonder if it is possible to access the file called blockerList.json which is in the folder Adblock Content Blocker . My goal was to write the json file based on what the user want to build. I need to be able to modify the content of this file. Is this possible or should I stop trying and leave it like that?

Thanks for any help.

Answer 1

Note : You have readonly permission for application's bundle file.

1. Firstly copy file in NSDocumentDirectory with backup attribute. Use refrerence copy file to document directory iphone and for How do I prevent files from being backed up to iCloud and iTunes?
2. Check references ImportingJSONFile and Y6JSONFileManager-iOS to read and write changes in JSON File.

Answer 2

The app bundle is readonly as @dan said. So you have to copy the file from bundle into the Document directory then you able to modify the file at anytime.

Copy file into document like this:

class func copyFile(fileName: String) {
    let destPath: String = getPathInDocument(fileName)
    var fromPath = NSBundle.mainBundle().pathForResource("blockerList", ofType: "json")!

    var fileManager = NSFileManager.defaultManager()
    if !fileManager.fileExistsAtPath(destPath) {
        fileManager.copyItemAtPath(fromPath, toPath: destPath, error: nil)
    } else {
        println("The file allready exists at path:\(destPath)")
    }

}

class func getPathInDocument(fileName: String) -> String {
    return NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)[0].stringByAppendingPathComponent(fileName)
}

Hope this will help you!