Planning Poker

A lightweight implementation of a Planning Poker (aka Scrum Poker) web application. The browser code uses HTML5 websockets when they are detected else does a graceful fallback to AJAX in legacy browsers. The server is a single jar file which runs on a standard Java JVM. The server logic is written in Scala using the core Akka libraries for concurrency and reactive programming. The networking layer is Netty 4 using the awesome Socko server. The code comes with back build and launch scripts which run on the Redhat Openshift PaaS cloud.

Build Prerequisites

Java Platform (JDK 7+) http://www.oracle.com/technetwork/java/javase/downloads/index.html
SBT http://www.scala-sbt.org/release/docs/Getting-Started/Setup.html#installing-sbt

Building

git clone https://github.com/simbo1905/planning-poker.git planning-poker
cd planning-poker
sbt test

Running

Running from a local build:

sbt run

Create a runnable jar to deploy and start it with

sbt assembly
java -jar ./target/scala-2.10/planning-poker-runnable.jar 127.0.0.1 80

N.B. You would need to sudo the command to run on port 80 on Mac OSX or other secure system (see .openshift/action_hooks/* for RHEL scripts).

You should see the output:

Serving web content out of src/main/resources
Open a few browsers and navigate to http://localhost:80. Start playing!

You can now go to that local url and play.

Press Ctrl+c to kill the process which stops the server.

The process takes two mandatory and two optional arguments:

IP/interface to bind to
Port to serve static content
Websocket alternative port (defaults to static content port)
Graceful websocket polling port (defaults to static content port)

The .openshift/action_hooks/README.md explains the optional parameters.

Creating A Skin

The site is effectively two pages under src/main/resources which are index.html and poker.html. The messages sent and received from the server show up on the browsers javascript console (e.g. firefox / chrome web developers console) as out> and in> entries which mean out from the browser to the server else in from the server to the browser, e.g.

out> {"mType":"Reveal"}
in>  {"cards":[{"player":"417007700350734336","card":13,"mType":"CardDrawn"},{"player":"417007962322767872","card":8,"mType":"CardDrawn"}],"mType":"CardSet"}"

shows that a player had hit the reveal cards button which sent a message of type "Reveal" to the server. The server responded with a message of type "CardSet" which contained two "CardDrawn" entries for two players which had values "8" and "13".

The complete set of messages are defined in the file /planning-poker/src/main/scala/scrumpoker/game/Messages.scala

RoomSize: Sent to all browsers when a player enters the room. Should be used to give a visual indication that more players have joined the room. Also sent to all browsers in response to a reset message.
DrawnSize: Sent to all browsers when a player selects a card. Should be used to indicate how many players in the room have selected a card. A message is also sent to all browsers in response to a reset message to show zero cards drawn.
CardSet: Sent to all browsers when the cards are revealed in response to a Reveal message. Contains the complete state of the game as the list of CardDrawn messages sent by all the players.
CardDrawn: Sent from the browser when a player selects a card.
CardUndrawn: Sent from the browser when a player unselects the card they had selected.
PlayerExit: Sent from the browser to the server when the browser window is closed.
Reveal: Sent from the browser to the server when a player presses the reveal button. Results in a CardSet being sent to all browsers.
Reset: Sent from the browser to the server when a player presses the rest button. Results in a Reset, RoomSize message and DrawnSize zero message being sent to all browsers to cause the game state to be cleared.

License

Apache 2.0 http://apache.org/licenses/LICENSE-2.0.html

TODO

[] Compress the static resources [] Check the alternate websocket port is reachable and fallback to polling if not [] If the room timesout check that all the polling players are shutdown [] Move all logging including websocket activity to the socko logs with writeWebLog()

End.