INT-1392 added groovy docs

src/docbkx/groovy.xml

@@ -0,0 +1,73 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
+"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
+<chapter id="groovy">
+  <title>Groovy support</title>
+	<para>
+	With Spring Integration 2.0 we've added Groovy support allowing you to use Groovy scripting language to provide 
+	integration and business logic  for various integration components similar to the way Spring Expression Language (SpEL) 
+	is use to implement routing, transformation and other integration concerns.
+    
+    For more information about Groovy please refer to Groovy documentation which you can find here: http://groovy.codehaus.org/
+	</para>
+
+  <section id="groovy-config">
+    <title>Groovy configuration</title>
+    <para>
+      Depending on the complexity of your integration requirements Groovy scripts could be provided inline as CDATA in XML 
+      configuration or as a reference to a file containing Groovy script.
+      
+      To enable Groovy support Spring Integration defines <classname>GroovyScriptExecutingMessageProcessor</classname> which will 
+      create a groovy Binding object identifying Message Payload as <code>payload</code> variable and Message Headers as 
+      <code>headers</code> variable. All that is left for you to do is write script that uses these variables.
+      Below are couple of sample configurations:
+      </para>
+      
+      <para>
+      <emphasis>Filter</emphasis>
+      <programlisting language="xml">&lt;filter input-channel="referencedScriptInput"&gt;
+   &lt;groovy:script location="some/path/to/groovy/file/GroovyFilterTests.groovy"/&gt;
+&lt;/filter&gt;
+
+&lt;filter input-channel="inlineScriptInput"&gt;
+   	&lt;groovy:script&gt;&lt;![CDATA[
+     return payload == 'good'
+   ]]&gt;&lt;/groovy:script&gt;
+&lt;/filter&gt;</programlisting>
+You see that script could be included inline or via <code>location</code> attribute using the groovy namespace sport. 
+    </para>
+    
+    <para>
+    Other supported elements are <emphasis>router, service-activator, transformer, splitter</emphasis>
+    </para>
+    
+    <para>
+    Another interesting aspect of using Groovy support is framework's ability to update (reload) scripts 
+    without restarting the Application Context.
+    To accomplish this all you need is specify <code>refresh-check-delay</code> attribute on <emphasis>script</emphasis>
+    element. The reason for this attribute is to make reloading of  the script more efficient. 
+    
+    <programlisting language="xml"><![CDATA[<groovy:script location="..." refresh-check-delay="5000"/>]]></programlisting>
+    
+    In the above example for the next 5 seconds after you update the script you'll still be using the old script and 
+    after 5 seconds the context will be updated with the new script. This is a good example where  'near real time' 
+    is acceptable.
+    
+     <programlisting language="xml"><![CDATA[<groovy:script location="..." refresh-check-delay="0"/>]]></programlisting>
+     
+     In the above example the context will be updated with the new script every time the script is modified. Basically this is the example of the 
+     'real-time' and might not be the most efficient way.
+     
+     <programlisting language="xml"><![CDATA[<groovy:script location="..." refresh-check-delay="-1"/>]]></programlisting>
+     
+    
+    Any negative number value means the script will never be refreshed after initial initialization of application context. 
+    DEFAULT BEHAVIOR
+    
+    <important>Inline defined script can not be reloaded.</important>
+    
+    </para>
+    
+  </section>
+
+</chapter>

src/docbkx/index.xml

@@ -88,6 +88,7 @@
   <xi:include href="./event.xml"/> 
   <xi:include href="./xml.xml"/>
   <xi:include href="./security.xml"/>
+  <xi:include href="./groovy.xml"/>
   <xi:include href="./samples.xml"/>
   <xi:include href="./configuration.xml"/>
   <xi:include href="./resources.xml"/>