iluwatar#467 data-bus: README.md: updated for data-bus

Author: kemitix

data-bus/README.md

@@ -7,24 +7,30 @@ permalink: /patterns/data-bus/ # the permalink to the pattern, to keep this unif
 # both categories and tags are Yaml Lists
 # you can either just pick one or write a list with '-'s
 # usable categories and tags are listed here: https://github.com/iluwatar/java-design-patterns/blob/gh-pages/_config.yml
-categories: creational # categories of the pattern
+categories: Architectural # categories of the pattern
 tags: # tags of the pattern
- - best
- - ever
- - awesome
+ - Java
+ - Difficulty-Intermediate
 ---
 
 ## Intent
-Makes your code awesome
 
-![alt text](./etc/best_pattern.png "Best Pattern Ever")
+Allows send of messages/events between components of an application
+without them needing to know about each other. They only need to know
+about the type of the message/event being sent.
+
+![data bus pattern uml diagram](./etc/data-bus.urm.png "Data Bus pattern")
 
 ## Applicability
-Use the Best Pattern Ever pattern when
+Use Data Bus pattern when
 
-* you want to be the best
-* you need to ...
+* you want your components to decide themselves which messages/events they want to receive
+* you want to have many-to-many communication
+* you want your components to know nothing about each other
 
-## Real world examples
+## Related Patterns
+Data Bus is similar to
 
-* [Nowhere](http://no.where.com)
+* Mediator pattern with Data Bus Members deciding for themselves if they want to accept any given message
+* Observer pattern but supporting many-to-many communication
+* Publish/Subscribe pattern with the Data Bus decoupling the publisher and the subscriber