Developing TicToe HTML5/Implementing Server Entities

Development log of TicToe HTML5

• Why tic tac toe?‎
• Idea and concept
• Core
  • User interface mock
  • Object model
  • Implementing Client Entities
  • Preparing the Server
  • Implementing Server Entities
  • Client-Server communication
  • Implementing the game logic
• Adding Features
  • Login and account creation
  • Hall of fame
  • Avatars and outfits

Now we have a user interface on the client side. Lets have a look at the server. The server is the place where all the interesting logic will happen. But before we can start coding the game rules, we need to implement the entities.

As we are using different programming languages for the client and the server, we have to do this again.

We start with a stub for the Entity class, which we will put into the folder net/sf/arianne/tictoe/server/entity. The prefix is generated by reversing our domain name arianne.sf.net to ensure a unique name space.

Entity class

We define two constructors: A simple one without parameters that is used by our code to create a new Entity. And a second one with an RPObject as parameter. This one is used when Marauroa creates an Entity based on information stored in the database:

<source lang="java"> package net.sf.arianne.tictoe.server.entity;

import marauroa.common.game.Definition.Type; import marauroa.common.game.RPClass; import marauroa.common.game.RPObject;

/**

* the abstract base class of all Entities
*
* @author hendrik
*/

public abstract class Entity extends RPObject {

/** * creates a new Entity. */ public Entity() { // default constructor }

/** * creates a new Entity based on the provided RPObject * * @param object RPObject */ public Entity(RPObject object) { super(object); } } </source>

Now we need to tell Marauroa which attributes our entity class will have. Depending on the flags they will be sent to the client and/or stored to the database. For now, we use the x, y, z coordinates without any special flags:

<source lang="java"> /** * generates the RPClass */ public static void generateRPClass() { RPClass clazz = new RPClass("entity"); clazz.addAttribute("x", Type.INT); clazz.addAttribute("y", Type.INT); clazz.addAttribute("z", Type.INT); } </source>

It is a good design to make the interface of a class explicit. Therefore we define get- and set- method for those attributes:

<source lang="java"> /** /** * gets the x-coordinate * sets the x coordinate * * * @return x-coordinate * @param x x-coordinate */ */ public int getX() { public void setX(int x) { return super.getInt("x"); super.put("x", x); } }

/** /** * gets the y-coordinate * sets the y coordinate * * * @return y-coordinate * @param y y-coordinate */ */ public int getY() { public void setY(int y) { return super.getInt("y"); super.put("y", y); } }

/** /** * gets the z-coordinate * sets the z coordinate * * * @return z-coordinate * @param z z-coordinate */ */ public int getZ() { public void setZ(int z) { return super.getInt("z"); super.put("z", z); } } </source>

These simple methods may seem like a waste of space, but they will make things a lot easier later.

Gameboard class

The game board class is rather simple for now. It is a specialisation of the Entity class both in the Java world as in the Marauroa type definition. It does not define any additional attributes for now.

<source lang="java"> package net.sf.arianne.tictoe.server.entity;

import marauroa.common.game.RPClass; import marauroa.common.game.RPObject;

/**

* a game board
*
* @author hendrik
*/

public class Gameboard extends Entity { /** * creates a new Gameboard. */ public Gameboard() { // default constructor }

/** * creates a new Gameboard based on the provided RPObject * * @param object RPObject */ public Gameboard(RPObject object) { super(object); }

/** * generates the RPClass */ public static void generateRPClass() { RPClass clazz = new RPClass("gameboard"); clazz.isA("entity"); } } </source>

This is the place where we will implement most of the game logic later.

Token class

The token class extends Entity like the Gameboard did. But it adds a tokenType attribute:

<source lang="java"> ... public class Token extends Entity { private static final String ATTR_TOKEN_TYPE = "tokenType";

...

/** * gets the token type. * * @return "x" or "o" */ public String getTokenType() { return super.get(ATTR_TOKEN_TYPE); }

/** * sets the token type. * * @param tokenType type of token ("x", "o") */ public void setTokenType(String tokenType) { super.put(ATTR_TOKEN_TYPE, tokenType); }

/** * generates the RPClass */ public static void generateRPClass() { RPClass clazz = new RPClass("token"); clazz.addAttribute(ATTR_TOKEN_TYPE, Type.STRING); clazz.isA("entity"); } </source>

Note: We have left out the imports and constructors as they follow the pattern of the previous shown classes.

Player class

The last entity class is the one which represents players. For now, they just have a name, but later they will represent the clients and may be extended to full avatars with nice outfits.

<source lang="java"> ... public class Player extends Entity { private static final String ATTR_PLAYER_NAME = "playerName";

... /** * gets the name of the player * * @return name of player */ public String getPlayerName() { return super.get(ATTR_PLAYER_NAME); }

/** * sets the name of the player * * @param playerName */ public void setPlayerName(String playerName) { super.put(ATTR_PLAYER_NAME, playerName); }

/** * generates the RPClass */ public static void generateRPClass() { RPClass clazz = new RPClass("player"); clazz.addAttribute(ATTR_PLAYER_NAME, Type.STRING); clazz.isA("entity"); } } </source>

Again the imports and constructors have been left out.