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
