我想将JSON数据传递给与Web视图相关的javascript函数。 但是我无法从Javascript函数中获取响应数据

Question

When printing 'b' value, I am getting empty. Means the data I have sent was wrong.

Am I doing anything wrong?

Here is my code :

Swift 4.0

let inputPayload: Dictionary = ["wellname": ["answer": "firstName"]]

if JSONSerialization.isValidJSONObject(inputPayload) {
  do {
    let rawData =
      try JSONSerialization.data(withJSONObject: inputPayload, options: [])

    let b = webView.stringByEvaluatingJavaScript(from: "downloadComplete(\(rawData))") !
      print(b)
  } catch {

  }
}

This is my Javascript function

function downloadComplete(a) {
  return a.wellname.answer
}

Answer 1

Objective-c

- (void)runJavaScriptCallback:(NSString *) jsonString {
    NSString *exec_template = @"downloadComplete(\'%@\');";
    NSString *exec = [NSString stringWithFormat:exec_template, jsonString];

    [webView evaluateJavaScript:exec completionHandler:nil];
}

Swift 4

func runJavaScriptCallback(jsonString: String) {
    webView.evaluateJavaScript("downloadComplete(\(jsonString))") { result, error in
        guard error == nil else {
            print(error)
            return
        }
    }
}

Javascript

var downloadComplete = (bridgeMsg) => {
  // escape newline character from iOS sdp
  bridgeMsg = bridgeMsg.replace(/\r?\n|\r/g, '\\r\\n');

  const msg = JSON.parse(bridgeMsg);
  // do whatever you want with the parsed json object
};