LP#1631522: add release notes for ->dispatch

Signed-off-by: Galen Charlton <gmc@esilibrary.com>

diff --git a/doc/Dispatch-Mode-for-Subrequests.txt b/doc/Dispatch-Mode-for-Subrequests.txt
new file mode 100644 (file)
index 0000000..6b3a121
--- /dev/null
+++ b/doc/Dispatch-Mode-for-Subrequests.txt
@@ -0,0 +1,12 @@
+Dispatch mode for method_lookup Subrequests
+===========================================
+
+There is a pattern in the wild of using OpenSRF's method_lookup() facility
+to decide between one of several local methods when delegating to pre-existing
+logic.  Often times, we want to simply hand control over to another method,
+but the output of a subrequest's run() is an array of results.  The caller has
+to know if, and how, to restructure the result for the client.
+
+Instead, we can now call dispatch() instead of run() and have OpenSRF session
+control completely passed to the delegate code.  This way, the delegate code
+need not know anything about its caller, and vice versa.