Android: return String using javascript on webview

Question

My goal is to set a String equals to a text inside an HTML page loaded into my webview. This is the HTML code:

<!DOCTYPE html>
<html>
<body>
<span class="txtTitle" style="color:#f93f3f; font-size:17px;">Hello World</span>
</body>
</html>

What I would like to know is to pass the "Hello World" in a String.

What I have already done is this:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    WebView view = (WebView) findViewById(R.id.webView);
    WebSettings asd = view.getSettings();
    String url = "http://example.net";
   asd.setJavaScriptEnabled(true);
   view.loadUrl(url);
    view.setWebViewClient(new WebViewClient() {
        public void onPageFinished(WebView view, String url) {
        String text;    
        text = view.loadUrl("javascript:document.getElementsByClassName('txtTitle')[0].innerHTML");
        }
    });
    }

But of course it gives me an error saying that the loadValue() can't be a String. Any Advice??

Manish · Accepted Answer · 2015-05-08 23:29:09Z

1

You can bind javascript to android code in order to return a string.

Read more: http://developer.android.com/guide/webapps/webview.html#BindingJavaScript

Here's a simple example to accomplish your goals.

public class MainActivity extends Activity {

WebView view;
JSInterface api;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    view = (WebView) findViewById(R.id.webView);
    api = new JSInterface();
    WebSettings asd = view.getSettings();

    asd.setJavaScriptEnabled(true);
    view.addJavascriptInterface(api, "api");

    String url = "file:///android_asset/index.html";
    view.loadUrl(url);
    view.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }

        public void onPageFinished(WebView view, String url) {
            view.loadUrl("javascript:api.getString(document.getElementsByClassName('txtTitle')[0].innerHTML)");
        }
    });
}

private class JSInterface {

    @JavascriptInterface
    public void getString(String str) {
        Log.d("STRING", str);
    }

}
}

answered May 8, 2015 at 23:29

Manish

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1 Comment

Alessio Trecani Over a year ago

Thanks very very much for the answer man. Just last question If I would try to print the String that I got what should I do.. Which is the variable i got from this code

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