[jboss-cvs] JBoss Messaging SVN: r6835 - trunk/docs/user-manual/en/modules.

[jboss-cvs-commits at lists.jboss.org]

Author: timfox
Date: 2009-05-18 06:35:56 -0400 (Mon, 18 May 2009)
New Revision: 6835

Modified:
   trunk/docs/user-manual/en/modules/filter-expressions.xml
Log:
filter expressions

Modified: trunk/docs/user-manual/en/modules/filter-expressions.xml
===================================================================
--- trunk/docs/user-manual/en/modules/filter-expressions.xml	2009-05-18 09:50:55 UTC (rev 6834)
+++ trunk/docs/user-manual/en/modules/filter-expressions.xml	2009-05-18 10:35:56 UTC (rev 6835)
@@ -1,7 +1,55 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <chapter id="filter-expressions">
     <title>Filter Expressions</title>
-    <para></para>
-    
-    
+    <para>JBoss Messaging provides a powerful filter language based on a subset of the SQL 92
+        expression syntax.</para>
+    <para>It is very similar to the syntax used for JMS selectors. For documentation on JMS selector
+        syntax please the JMS javadoc for <ulink
+            url="http://java.sun.com/javaee/5/docs/api/javax/jms/Message.html"
+            >javax.jms.Message</ulink>.</para>
+    <para>Filter expressions are used in several places in JBossMessaging</para>
+    <itemizedlist>
+        <listitem>
+            <para>Predefined Queues. When pre-defining a queue, either in <literal
+                    >jbm-configuration.xml</literal> or <literal>jbm-jms.xml</literal> a filter
+                expression can be defined for a queue. Only messages that match the filter
+                expression will enter the queue.</para>
+        </listitem>
+        <listitem>
+            <para>Core Bridges can be defined with an optional filter expression, only matching
+                messages will be bridged. See the section [LINK]</para>
+        </listitem>
+        <listitem>
+            <para>Diverts can be defined with an optional filter expression, only matching messages
+                will be diverted. See the section [LINK]</para>
+        </listitem>
+        <listitem><para>Filter are also used programmatically when creating consumers, queues and in several places in the management API.</para></listitem>
+    </itemizedlist>
+    <para>There are some differences between JMS selector expressions and JBoss Messaging core
+        filter expressions. Whereas JMS selector expressions operate on a JMS message, JBoss
+        Messaging core filter expressions operate on a core message.</para>
+    <para>The following identifiers can be used in a core filter expressions to refer to attributes
+        of the core message in an expression:</para>
+    <itemizedlist>
+        <listitem>
+            <para><literal>JBMPriority</literal>. To refer to the priority of a message. Message
+                priorities are integers with valid values from <literal>0 - 9</literal>. <literal
+                    >0</literal> is the lowest priority and <literal>9</literal> is the highest.
+                E.g. <literal>JBMPriority = 3 AND animal = 'aardvark'</literal></para>
+        </listitem>
+        <listitem>
+            <para><literal>JBMExpiration</literal>. To refer to the expiration time of a message. The value is a long integer.</para>
+        </listitem>
+        <listitem>
+            <para><literal>JBMDurable</literal>. To refer to whether a message is durable or not. The value is a string with valid values:
+            <literal>DURABLE</literal> or <literal>NON_DURABLE</literal>.</para>
+        </listitem>
+        <listitem>
+            <para><literal>JBMTimestamp</literal>. The timestamp of when the message was created. The value is a long integer.</para>
+        </listitem>
+        <listitem>
+            <para><literal>JBMSize</literal>. The size of a message in bytes. The value is an integer.</para>
+        </listitem>
+    </itemizedlist>
+    <para>Any other identifiers used in core filter expressions will be assumed to be properties of the message.</para>
 </chapter>