FROM URL：http://blog.csdn.net/nizhenyang/article/details/26339383

感谢原作者nizhenyang分享这样好的实战案例！

概述

这是一篇通过一个简单的 treasure 捡宝的例子讲述如何使用 Bearcat 来快速, 高效的进行 pomelo game 开发

起步

添加 bearcat

npm install bearcat --save

添加context.json, 并指定 scan 扫描路径, 来自动扫描 POJOs

context.json

{    "name": "bearcat-treasures",    "scan": "app",    "beans": []}

修改app.js, 添加 bearcat 启动代码

app.js

var contextPath = require.resolve('./context.json');bearcat.createApp([contextPath]);bearcat.start(function() {  Configure(); // pomelo configure in app.js  app.set('bearcat', bearcat);  // start app  app.start();});

就是这么简单, bearcat 开发环境就已经搭建完毕, 之后就可以利用 bearcat 所提供的 IoC, AOP, 一致性配置等特性来编写简单, 可维护的 pomelo 应用

途中

handler, remote 交由 bearcat 管理

handler, remote 都以 POJO 的形式编写

由于之前handler, remote在pomelo里面是通过 pomelo-loader 来管理的, 因此需要做一下适配转化

m

通过适配, gateHandler 就交给了 bearcat 来进行管理, 之后 gateHandler 需要什么依赖, 仅仅在 getBean 的 metadata 配置中描述好依赖关系就行了

上面的gateHandler例子中, 就向 bearcat 容器描述了, gateHandler 需要在构造函数中传入一个 app 对象, 在对象属性中需要一个 dispatcher 依赖

domain 对象编写

domain 代表着数据和模型, 包括玩家player, 宝物treasure, 移动move等等

domain 里的数据要被序列化, 需要定义序列化方法, 比如toJSON

entity.js

var EventEmitter = require('events').EventEmitter;var util = require('util');var id = 1;function Entity(opts) {    EventEmitter.call(this);    this.opts = opts || {};    this.entityId = id++;    this.kindId = opts.kindId;    this.kindName = opts.kindName;    this.areaId = opts.areaId || 1;    this.x = 0;    this.y = 0;}util.inherits(Entity, EventEmitter);Entity.prototype._init = function() {    var opts = this.opts;    if (opts.x === undefined || opts.y === undefined) {        this.randPos();    } else {        this.x = opts.x;        this.y = opts.y;    }}Entity.prototype._toJSON = function() {    return {        x: this.x,        y: this.y,        entityId: this.entityId,        kindId: this.kindId,        kindName: this.kindName,        areaId: this.areaId    }}// random positionEntity.prototype.randPos = function() {};module.exports = {    id: "entity",    func: Entity,    abstract: true,    props: [{        name: "dataApiUtil",        ref: "dataApiUtil"    }, {        name: "utils",        ref: "utils"    }]}

entity 是一个抽象的bean, 意味着它只是作为子bean的模版, 并不会被实例化, 它通过对象属性依赖注入了 dataApiUtil 和 util

player.js

var logger = require('pomelo-logger').getLogger('bearcat-treasures', 'Player');var bearcat = require('bearcat');var util = require('util');function Player(opts) {  this.opts = opts;  this.id = opts.id;  this.type = null;  this.name = opts.name;  this.walkSpeed = 240;  this.score = opts.score || 0;  this.target = null;}Player.prototype.init = function() {  this.type = this.consts.EntityType.PLAYER;  var Entity = bearcat.getFunction('entity');  Entity.call(this, this.opts);  this._init();}Player.prototype.addScore = function(score) {  this.score += score;};Player.prototype.toJSON = function() {  var r = this._toJSON();  r['id'] = this.id;  r['type'] = this.type;  r['name'] = this.name;  r['walkSpeed'] = this.walkSpeed;  r['score'] = this.score;  return r;};module.exports = {  id: "player",  func: Player,  scope: "prototype",  parent: "entity",  init: "init",  args: [{    name: "opts",    type: "Object"  }],  props: [{    name: "consts",    ref: "consts"  }]}

player 是 entity 的一个子类, 它通过在metadata配置中的 parent 继承了 entity prototype 里的方法

player 的scope是 prototype 的, 并且需要定义一个 init 方法, 来调用 entity 的构造函数以及 entity 的 init 方法 _init

var Entity = bearcat.getFunction('entity'); Entity.call(this, this.opts); this._init();

这里通过 bearcat.getFunction 来拿到 entity 的构造函数来进行调用

使用 domain

在没有bearcat的情况下, 使用domain需要自己先require进来, 然后再 new domain(), 现在你可以直接通过 getBean 来得到相应 domain 的实例

playerHandler enterScene

PlayerHandler.prototype.enterScene = function(msg, session, next) {  var role = this.dataApiUtil.role().random();  var player = bearcat.getBean('player', {    id: msg.playerId,    name: msg.name,    kindId: role.id  });  player.serverId = session.frontendId;  if (!this.areaService.addEntity(player)) {    logger.error("Add player to area faild! areaId : " + player.areaId);    next(new Error('fail to add user into area'), {      route: msg.route,      code: this.consts.MESSAGE.ERR    });    return;  }  var r = {    code: this.consts.MESSAGE.RES,    data: {      area: this.areaService.getAreaInfo(),      playerId: player.id    }  };  next(null, r);};

var player = bearcat.getBean('player', {    id: msg.playerId,    name: msg.name,    kindId: role.id  });

player 通过 bearcat.getBean 拿到

domain 事件的处理

移动和捡宝是通过 event 事件来处理的, 在一个 tick 时间内, 当移动到宝物的捡宝范围之内, 就会出发 pickItem 事件

Move.prototype.update = function() {  var time = Date.now() - this.time;  var speed = this.entity.walkSpeed;  var moveLength = speed * time / 1000;  var dis = getDis(this.entity.getPos(), this.endPos);  if (dis <= moveLength / 2) {    this.finished = true;    this.entity.setPos(this.endPos.x, this.endPos.y);    return;  } else if (dis < 55 && this.entity.target) {    this.entity.emit('pickItem', {      entityId: this.entity.entityId,      target: this.entity.target    });  }  var curPos = getPos(this.entity.getPos(), this.endPos, moveLength, dis);  this.entity.setPos(curPos.x, curPos.y);  this.time = Date.now();};

触发时间后, 就向channel广播捡宝这个事件

player.on('pickItem', function(args) {    var player = self.getEntity(args.entityId);    var treasure = self.getEntity(args.target);    player.target = null;    if (treasure) {      player.addScore(treasure.score);      self.removeEntity(args.target);      self.getChannel().pushMessage({        route: 'onPickItem',        entityId: args.entityId,        target: args.target,        score: treasure.score      });    }  });

areaService 编写

areaService 里面维护着当前area里面的玩家, 排名, 宝物等数据

它在tick时间内, 向channel广播更新着area里面的最新数据

AreaService.prototype.tick = function() {  //run all the action  this.actionManagerService.update();  this.entityUpdate();  this.rankUpdate();}

entityUpdate 更新着area里面的entity情况

AreaService.prototype.entityUpdate = function() {  if (this.reduced.length > 0) {    this.getChannel().pushMessage({      route: 'removeEntities',      entities: this.reduced    });    this.reduced = [];  }  if (this.added.length > 0) {    var added = this.added;    var r = [];    for (var i = 0; i < added.length; i++) {      r.push(added[i].toJSON());    }    this.getChannel().pushMessage({      route: 'addEntities',      entities: r    });    this.added = [];  }};

总结

在bearcat的统一管理协调下, 去除了烦人的require直接依赖关系, 可以放心大胆的进行编码甚至重构, bearcat 里面的任一组件都被有序的管理维护着, 使用时不再是一个个单一的个体, 而是一个集体

项目代码在 bearcat-treasures