Shrink wurfl mobile database

WURFL is nice mobile database. The j2mepolish database is good too. Anyway I was trying to use wurfl.xml file(you can download it from wurfl homepage) while releasing my j2me application. But as the wurfl.xml file is too big(4.3M), I have removed some unused attributes and tags from it. And still I am able to use the parsers (I tested only the perl parser :-P ). Finally the size is reduced to (1.4M) .

My primary goal is to resize some of my background images appropriate to the the screen resolution for a specific mobile. So I filtered the resolution_width and resolution_height information.

Here is the small xslt code used to shrink the wurfl.xml .

<?xml version="1.0" ?>

<!--

This file part of MiniIM.

Copyright (C) 2007  Kamanashis Roy

MiniIM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

MiniIM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with MiniIM.  If not, see <http://www.gnu.org/licenses/>.

-->


<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

<xsl:output method="xml" indent="yes"/> 

<!-- select the device tag -->
<xsl:template match="/wurfl">

       <wurfl>
  <xsl:copy-of select="version"/>
  <devices>
   <xsl:apply-templates select="devices/device"/>

  </devices>
 </wurfl>
</xsl:template>

<!-- process devices -->
<xsl:template match="device">

        <device fall_back="{@fall_back}" id="{@id}" user_agent="{@user_agent}">
  <!-- keep only display group -->

           <xsl:apply-templates select="group[@id='display']"/>
        </device>
</xsl:template>

<xsl:template match="group">

 <!-- render non empty group -->
 <xsl:if test="count(capability[@name='resolution_width'])=1">
   <group id="{@id}">

    <xsl:apply-templates select="capability[@name='resolution_width']"/>
    <xsl:apply-templates select="capability[@name='resolution_height']"/>
   </group>

 </xsl:if>
</xsl:template>

<xsl:template match="capability">
 <capability name="{@name}" value="{@value}"/>

</xsl:template>

</xsl:stylesheet>

Now let us do the transform, I have used xsltproc for the transform here, you may want to get xsltproc binary for your os or get source here. And you can apply transform like this,

shell> xsltproc your_shrinker.xslt wurfl.xml > wurfl_shrinked.xml

You can do some appropriate modifications to this code to keep some other attributes too. I prefer to write separate xsl code for each application. Note there are other alternatives, like database
usage available in wurfl site. So please read those docs before trying this :) .

Finally I used the cool perl module form imagemagick to resize my images :) .

Enjoy !