Question

a lot of Android developer implement their own webview.
Although a lot of questions related to this topic are discussed on stackoverflow, here is probably a cause of this lack of clarity.

To open links within your WebView, android developer define their own webview.

• According to http://developer.android.com/guide/webapps/webview.html returning false in shouldOverrideUrlLoading should be used, to open the url in the current Webview.
  (“current” means presumably created or used lately?)

• According to http://developer.android.com/resources/tutorials/views/hello-webview.html and various blogs:

  public boolean shouldOverrideUrlLoading(WebView view, String url) {
     view.loadUrl(url);
     return true;
  }
  

  true must me returned.

Is there a mistake in one of the developer sites? It there difference between API level?
What is the cleanest and best use of shouldOverrideUrlLoading?

An answer would help our team and a lot of other developers working with android webviews.Thanks.

Answer 1

In case you decide to implement WebViewClient:

webView.setWebViewClient(new WebViewClient()
{
  @Override
  public boolean shouldOverrideUrlLoading(WebView view, String url)
  {
    // My own condition to decide if I should skip URL loading
    boolean avoidURLLoading = ...

    if (avoidURLLoading)
    {
      // Ask the WebView to avoid loading the URL,
      // I want to manage this case on my own.
      return true;
    }
    else
    {
      // Let the WebView load the URL 
      return false;
    }
  };
});

If you don’t implement WebViewClient, every time you’ll ask the WebView to load an URL with the loadUrl method, it will ask the Activity Manager to find a proper app to load the URL (typically a web browser installed in the device).

The default implementation of shouldOverrideUrlLoading in WebViewClient is

public boolean shouldOverrideUrlLoading(WebView view, String url)
{
  return false;
}

So if you just write something like this

webView.setWebViewClient(new WebViewClient());

the URL will load inside your own WebView and not in an external web browser.

You’ll typically return true in shouldOverrideUrlLoading when you want to modify the URL and then load the new one with another loadUrl call or when you just want to avoid loading the URL and handle the request in a different way.

The behavior in your example

public boolean shouldOverrideUrlLoading(WebView view, String url)
{
  view.loadUrl(url);
  return true;
}

is equivalent to

public boolean shouldOverrideUrlLoading(WebView view, String url)
{
  return false;
}

because you’re telling the WebView to avoid handling the URL loading (return true), but you’re also making another request with view.loadUrl(url) so in fact you end up loading the URL.