CODEWITHSUNDEEP
javajavascriptandroidhtmlwebview
YosiFZ
YosiFZ

Reputation: 7900

Run JavaScript method and return parameter

I want to run JavaScript function on my android app,this is how i create the webview:

m_FullJSWebView = new WebView(m_VideoView.getContext());
m_FullJSWebView.loadData(htmltmp, "text/html", "UTF-8");
m_FullJSWebView.getSettings().setJavaScriptEnabled(true);
m_FullJSWebView.addJavascriptInterface(new JavaScriptInterface(m_VideoView.getContext()), "MyAndroid");
m_FullJSWebView.loadUrl("javascript:getValue()");

This is the html:

<html>
  <head>
    <script type="text/javascript">
    function getValue(){
       //return value to Android 
       var val= 50;
       MyAndroid.receiveValueFromJs(val);
    }
    </script>
    <title></title>
  </head>
  <body >
    <form name="ipForm" id="ipForm">
      UserName : <input type="text" name="userName">
      <button type="button" onclick="getValue();">Submit</button>
    </form>
  </body>
</html>

And this is the JavascriptInterface:

public class JavaScriptInterface {
        Context mContext;
        JavaScriptInterface(Context c) {
            mContext = c;
        }
        //add other interface methods to be called from JavaScript

        public void receiveValueFromJs(String str) {
            //do something useful with str
              Toast.makeText(mContext, "Received Value from JS: " + str,Toast.LENGTH_SHORT).show();
        }
}

After i run it on my device the receiveValueFromJs function won't called.Any idea what is the problem?

Upvotes: 3

Views: 204

Answers (1)

njzk2
njzk2

Reputation: 39406

From the doc:

Note that injected objects will not appear in JavaScript until the page is next (re)loaded.

Which means that you must change your methods order like that:

m_FullJSWebView = new WebView(m_VideoView.getContext());
m_FullJSWebView.addJavascriptInterface(new JavaScriptInterface(m_VideoView.getContext()), "MyAndroid");
m_FullJSWebView.loadData(htmltmp, "text/html", "UTF-8");
m_FullJSWebView.getSettings().setJavaScriptEnabled(true);
m_FullJSWebView.loadUrl("javascript:getValue()");

edit (2nd issue)

the name parameter in the addJavascriptInterface is name of the java object in the javascript. it is the object on which to call the methods from the javascript.

Therefore, your call should be:

m_FullJSWebView.loadUrl("javascript:MyAndroid.getValue()");

Upvotes: 1

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