Android - how to intercept a form POST in android WebViewClient on API level 4
I have a WebViewClient
attached to my WebView
like so:
webView.setWebViewClient(new MyWebViewClient());
Here is my implementation of MyWebViewClient
:
private class MyWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
webView.loadUrl(url);
return true;
}
}
I give the WebView
a URL to load via loadUrl()
. If I have a link (a href...
) in the page, my shouldOverrideUrlLoading
method is called and I can intercept the link click.
However, if I have a form whose method is POST
, the shouldOverrideUrlLoading
method is not called.
I noticed a similar issue here: http://code.google.com/p/android/issues/detail?id=9122 which seems to suggest overriding postUrl
in my WebView
. However, this API is only available starting from API level 5.
What can I do if I'm on API level 4? Is there any other way to intercept form posts?
Do you really need to use a POST? If you want to handle formdata locally, why not have a piece of javascript handle your form and interface with "native" java code using addJavascriptInterface. E.g.
WebView engine = (WebView) findViewById(R.id.web_engine);
engine.getSettings().setJavaScriptEnabled(true);
engine.addJavascriptInterface(new MyBridge(this), "bridge");
engine.loadUrl(...)
Your bridge can be any class basically and you should be able to access its methods directly from javascript. E.g.
public class MyBridge {
public MyBridge(Context context) {
// ...
}
public String doIt(String a, String b) {
JSONArray result = new JSONArray();
result.put("Hello " + a);
result.put("Hello " + b);
return result.toString();
}
Your html / javascript could look like:
<script type="text/javascript">
$("#button").click(function() {
var a = $("#a").val();
var b = $("#b").val();
var result=JSON.parse(bridge.doIt(a, b));
// ...
}
</script>
<input id="a"><input id="b"><button id="button">click</button>
This is known issue, that shouldOverrideUrlLoading
don't catch POST. See http://code.google.com/p/android/issues/detail?id=9122 for details.
Use GET! I personally tried using POST, because I expected some limitation of GET parameters (i.e. length of URL), but I just successfully passed 32000 bytes through GET locally without any problems.