Browser version detect using GWT?

Question

Is there GWT api that will tell me which browser version it detected?

I've found a flaw with IE7's regex handling and need to code around some tricky String.matches() expressions.

Answer 1

You can detect the browser type using the code below.

public static native String getUserAgent() /*-{
return navigator.userAgent.toLowerCase();
}-*/;

Then you can call that function and look at the type of the browser. For example the code below decides whether it is internet explorer or not.

if(getUserAgent().contains("msie"))
{
///////// Write your code for ie
}

This page has the User Agent for just about every browser known to man.

Answer 2

You could use GWT deferred binding using replacement and create two implementations of your class in which you use regex.

For example let's assume your class is named Parser and it contains code for all web browsers except for IE7. Then you can extend Parser and create ParserIE7 class for IE7. Then in your GWT module config file you can add:

<replace-with class="Parser">
  <when-type-is class="Parser"/>
</replace-with>

<replace-with class="ParserIE7">
  <when-type-is class="Parser" />
  <when-property-is name="user.agent" value="ie7"/>
</replace-with>

Then by calling

Parser parser = GWT.create(Parser.class);

you should have a proper (web browser dependent) implementation of Parser in parser variable.

You can find more details here.