webkit – Displaying Android asset files in a WebView?-ThrowExceptions

Exception or error:

I have seen various discussions on the problem of serving WebView pages from assets, none of which seemed definitive.

I want to be able to use a webview to display html (and included css) files stored in the project assets.

I have found that wv.loadUrl(“file:///android_asset/html_no_copy/demo_welcome.html”) displays that file okay, but links in demo_welcome.html, either local (no url prefixing the file name) or absolute – the same form as fed to loadUrl – don’t work. They get a “Web page not available” error displayed on the view.

WebView wv = (WebView)this.findViewById(R.id.splashWebView);
wv.loadUrl("file:///android_asset/html_no_copy/test.html"); // Works

or

wv.loadUrl("file:///android_asset/html_no_copy/demo_welcome.html"); // Works

But neither of the following links in demo_welcome.html work:

<a href="test.html">CLICK HERE</a><p>
<a href="file:///android_asset/html_no_copy/test.html">OR HERE</a>

I know I can get around this by writing a content provider, but that seems extreme.

I want this to work from SDK 1.6 (4) on up.

Does anyone know if this can be done with just HTML, or does one need to kluge up some code to load the data?

How to solve:

Well, I found something that seems to work (on 1.6 and 2.2), in spite of a warning that it would recurse.

I also discovered that a css style-sheet link inside the first and second page both work without the following intercept. Odd and it makes me a bit nervous. Thoughts?

Here’s the code:

WebView wv = (WebView)this.findViewById(R.id.splashWebView);
wv.setWebViewClient(new WebViewClient() {  
  @Override  
  public boolean shouldOverrideUrlLoading(WebView view, String url)  
  {  
    view.loadUrl(url);
    return true;
  }  
}); 
wv.loadUrl("file:///android_asset/html_no_copy/demo_welcome.html");

Here’s the file contents:

demo_welcome.html:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Demo Html</title>
    <link rel="stylesheet" type="text/css" href="demo.css" />
  </head>
  <body>
    <H1>Testing One Two Three</H1>
    <a href="test.html">CLICK HERE</a><p>
    <a href="file:///android_asset/html_no_copy/test.html">OR HERE</a>
  </body>
</html>

test.html:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <link rel="stylesheet" type="text/css" href="test.css" />
    <title>Insert title here</title>
  </head>
  <body>
    <H1>TEST.HTML</H1>
  </body>
</html>

###

instead of loadUrl, try using the loadDataWithBaseURL method:

wv.loadDataWithBaseURL("fake://not/needed", html, mimeType, encoding, "");

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