Author: rmannibucau
Date: Mon Oct 31 10:08:41 2011
New Revision: 1195389
URL: http://svn.apache.org/viewvc?rev=1195389&view=rev
Log:
adding a readme for cdi-events
Added:
openejb/trunk/openejb/examples/cdi-events/README.md
Added: openejb/trunk/openejb/examples/cdi-events/README.md
URL:
http://svn.apache.org/viewvc/openejb/trunk/openejb/examples/cdi-events/README.md?rev=1195389&view=auto
==============================================================================
--- openejb/trunk/openejb/examples/cdi-events/README.md (added)
+++ openejb/trunk/openejb/examples/cdi-events/README.md Mon Oct 31 10:08:41 2011
@@ -0,0 +1,32 @@
+# CDI events: loose coupling and extensibility
+
+CDI allows you to extend business code by the Notifier/Observer pattern.
+
+To do it you simply inject a field `Event` in the notifier class. This class
is a template
+and the parameter type is the object type to fire. Then when you want to
notify observers
+you simply call the method fire of the event object passing as a parameter the
event itself
+(your own class!).
+
+On the other side you annotated a method parameter `@Observes` and the
parameter type is the sent type
+by the notifier.
+
+Note: of course you can add qualifiers to be more precise on your events.
+
+# The example
+
+The example is pretty simple: an ejb uses the `@Schedule` annotation to get a
notification each second.
+The each second this EJB will send the current date through CDI events.
+
+This is our "business" code. It is a simple behavior (nothing).
+
+In our test (which is considered as an extension) we created an observer
(`Observer` class)
+which simply store and log each received date.
+
+The test itself (`EventTest`) simply verifies the dates were received.
+
+# Conclusion
+
+CDI let's implement very easily plugins through this event mecanism.
+
+If you go further and look at CDI plugin API you'll realize it is simply the
same kind
+of events. CDI events is really the basis of CDI.
