From 18b3a3656423581e5f209d20e8b97c7dca5c72b4 Mon Sep 17 00:00:00 2001
From: Mark Fisher <markfisher@vmware.com>
Date: Wed, 26 Nov 2008 01:01:07 +0000
Subject: [PATCH] Added note about ChannelInterceptors' pre/postReceive()
 methods only applying to PollableChannels

---
 spring-integration-reference/src/channel.xml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/spring-integration-reference/src/channel.xml b/spring-integration-reference/src/channel.xml
index 1ec95f25c8..bc2e24928d 100644
--- a/spring-integration-reference/src/channel.xml
+++ b/spring-integration-reference/src/channel.xml
@@ -221,6 +221,16 @@
         return message;
     }
 }]]></programlisting>
+      <note>
+        Keep in mind that <methodname>receive()</methodname> calls are only relevant for
+        <interfacename>PollableChannels</interfacename>. In fact the
+        <interfacename>SubscribableChannel</interfacename> interface does not even define a
+        <methodname>receive()</methodname> method. The reason for this is that when a Message is sent to a
+        <interfacename>SubscribableChannel</interfacename> it will be sent directly to one or more subscribers
+        depending on the type of channel (e.g. a PublishSubscribeChannel sends to all of its subscribers). Therefore,
+        the <methodname>preReceive(..)</methodname> and <methodname>postReceive(..)</methodname> interceptor methods
+        are only invoked when the interceptor is applied to a <interfacename>PollableChannel</interfacename>.
+      </note>
     </para>
   </section>