使用Javascript在Webview（Android）中填写表单而没有输入类型的元素ID（文本和密码）？

Question

I have opened the login page of a website(Cyberoam-college) in webview of my app. now I want to make it so that user won't have to type the username and password again and again, rather they can select it from a list or somewhere else and the app would automatically fill the username, password and click login for them. I've read that to do this I need to implement javascript in my webview.

The Problem is, both username and password fields don't have id in their html tags, just the name attribute-

<input type="text" name="username">
<input type="password" name="password">

The Login Button has ID, so it can be used-

<input type="submit" name="btnSubmit" value="Login" id="logincaption">

Now I somehow need to use strings stored in variables in MainActivity.java to fill first the username textField, then the password field and finally click the login button when user clicks the element in the list storing list of usernames and passwords.

Please tell me how to implement this in Android!

Answer 1

Thirst of all make sure that isn't iframe. I believe there was no reason to add a webView for login purposes if you can build native login. Anyway if you need to select inputs you can use:

  function login(){
        document.querySelector("input[name=username]").value  = "username";
        document.querySelector("input[name= password]").value  = "password";
        document.forms[0].submit();
 }

To pass values from Java code to JS you have to write a bridge and trigger JS function You can read how to build bridge here: http://blog.cuelogic.co.in/simple-android-java-javascript-bridge/

Answer 2

First, use the following statement

@SuppressLint("SetJavaScriptEnabled")

then, you could:

mWebView = (WebView) findViewById(R.id.webview); 
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebChromeClient(new WebChromeClient());
mWebView.setWebViewClient(new WebViewClient(){
    @Override
    public void onPageFinished(WebView view, String url) {

        String javascript="javascript: document.getElementById('someid').innerHTML='Hello World!';";
        view.loadUrl(javascript);
    }
});
mWebView.loadUrl(URL);

You can insert Java interfaces using this method to control the asynchronously via Java methods.