GXT 4 permutations, setting specific build properties.

Explorer.gwt.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit 2.7.0//EN"
  "http://gwtproject.org/doctype/2.7.0/gwt-module.dtd">
<module rename-to='explorer'>
  <inherits name='com.google.gwt.activity.Activity' />
  <inherits name='com.google.gwt.place.Place' />
  <inherits name="com.google.gwt.inject.Inject" />

  <inherits name='com.sencha.gxt.examples.resources.Resources' />
  <inherits name='com.sencha.gxt.chart.Chart' />
  
  <!-- Testing -->
  <inherits name="com.google.gwt.user.Debug"/>
  <inherits name="org.senchalabs.gwt.gwtdriver.gxt.TestableGXT" />

  <!-- https://docs.sencha.com/gxt/4.x/guides/concepts/Logging.html -->
  <set-property name="gwt.logging.logLevel" value="SEVERE" />
  <set-property name="gwt.logging.enabled" value="TRUE" />
  <set-property name="gxt.logging.enabled" value="false" />

  <!-- Include all base GXT themes and set the app to check for url params to activate a different one -->
  <inherits name="com.sencha.gxt.theme.blue.Blue" />
  <inherits name="com.sencha.gxt.theme.gray.Gray" />
  <inherits name="com.sencha.gxt.theme.neptune.Theme" />
  <inherits name="com.sencha.gxt.theme.triton.Theme" />
  <set-property name="gxt.theme" value="blue,gray,neptune,triton" />
  <property-provider name="gxt.theme"><![CDATA[
    if (window.location.pathname.indexOf('blue') != -1 || window.location.search.indexOf('blue') != -1) {
      return "blue";
    }
    if (window.location.pathname.indexOf('gray') != -1 || window.location.search.indexOf('gray') != -1) {
      return "gray";
    }
    if (window.location.pathname.indexOf('neptune') != -1 || window.location.search.indexOf('neptune') != -1) {
      return "neptune";
    }
    return "triton";
  ]]></property-provider>

  <set-property name="gxt.css3.enabled" value="false">
    <any>
      <when-property-is name="gxt.theme" value="blue" />
      <when-property-is name="gxt.theme" value="gray" />
    </any>
  </set-property>

  <set-configuration-property name="CssResource.enableGss" value="true" />
  <set-configuration-property name="CssResource.style" value="pretty" />

  <replace-with class='com.sencha.gxt.explorer.client.chart.BlueThemedChartAppearance'>
    <when-type-is class='com.sencha.gxt.explorer.client.chart.ThemedChartExample.ThemedChartAppearance'/>
    <when-property-is name="gxt.theme" value="blue" />
  </replace-with>
  <replace-with class='com.sencha.gxt.explorer.client.chart.GrayThemedChartAppearance'>
    <when-type-is class='com.sencha.gxt.explorer.client.chart.ThemedChartExample.ThemedChartAppearance'/>
    <when-property-is name="gxt.theme" value="gray" />
  </replace-with>
  <replace-with class='com.sencha.gxt.explorer.client.chart.NeptuneThemedChartAppearance'>
    <when-type-is class='com.sencha.gxt.explorer.client.chart.ThemedChartExample.ThemedChartAppearance'/>
    <when-property-is name="gxt.theme" value="neptune" />
  </replace-with>
  <replace-with class='com.sencha.gxt.explorer.client.chart.TritonThemedChartAppearance'>
    <when-type-is class='com.sencha.gxt.explorer.client.chart.ThemedChartExample.ThemedChartAppearance'/>
    <when-property-is name="gxt.theme" value="triton" />
  </replace-with>

  <!-- Specify the paths for translatable code -->
  <source path='client' />
  <source path='shared' />

  <generate-with class="com.sencha.gxt.explorer.rebind.SampleGenerator">
    <when-type-assignable class="com.sencha.gxt.explorer.client.model.ExampleModel" />
  </generate-with>

  <set-configuration-property name="GXT.state.autoBeanFactory" value="com.sencha.gxt.explorer.client.window.WindowStateExample.ExampleAutoBeanFactory" />

  <entry-point class='com.sencha.gxt.explorer.client.Explorer' />

  <stylesheet src="reset.css"/>

  <!-- collapse properties for fewer permutations -->
  <collapse-property name="gxt.device" values="phone, tablet" />
  <collapse-property name="gxt.theme" values="blue, gray" />
  <collapse-property name="gxt.user.agent" values="air, safari*, chrome*, gecko*, ie11" />
  <collapse-property name="user.agent" values="safari*, gecko*" />
  <collapse-property name="gxt.user.agent" values="ie8, ie9, ie10" />
  <collapse-property name="user.agent" values="ie*" />
  
  <!-- The property below is replaced from maven profile mvn install -Pfast-build -->
  <!--{profile.fast.build}-->
</module>

pom.xml

 <profile>
      <id>fast-build</id>
      <properties>
        <profile.fast.build>
          &lt;set-property name="user.agent" value="safari" /&gt;
          &lt;set-property name="gxt.user.agent" value="chrome" /&gt;
          &lt;set-property name="gxt.device" value="desktop" /&gt;
          &lt;set-property name="gxt.theme" value="triton" /&gt;
        </profile.fast.build>
      </properties>
      <build>
        <resources>
          <resource>
            <directory>src/main/java</directory>
            <filtering>true</filtering>
            <includes>
              <include>**/*.gwt.xml</include>
            </includes>
          </resource>
        </resources>
        
        <plugins>
                <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <version>3.0.2</version>
        <configuration>
          <encoding>UTF-8</encoding>
          <delimiters>&lt;!--{*}--&gt;</delimiters>
        </configuration>
      </plugin>
        </plugins>
      </build>
    </profile>

1. Set the properties in the pom.xml to replace settings in the gwt module descriptor.
2. Add the delimiters to the project module descriptor.
3. Call the profile out on the build mvn clean install -Pfast-build