2、策略模式
js
// 第一步
var performanceS = function(){};
performanceS.prototype.calculate = function( salary ){
return salary * 4;
};
var performanceA = function(){};
performanceA.prototype.calculate = function( salary ){
return salary * 3;
};
var performanceB = function(){};
performanceB.prototype.calculate = function( salary ){
return salary * 2;
};
var Bonus = function(){
this.salary = null; // 原始工资
this.strategy = null; // 绩效等级对应的策略对象
};
Bonus.prototype.setSalary = function( salary ){
this.salary = salary; // 设置员工的原始工资
};
Bonus.prototype.setStrategy = function( strategy ){
this.strategy = strategy; // 设置员工绩效等级对应的策略对象
};
Bonus.prototype.getBonus = function(){ // 取得奖金数额
return this.strategy.calculate( this.salary ); // 把计算奖金的操作委托给对应的策略对象
};
// 段代码是基于传统面向对象语言的模仿
// 第二步
// 所有跟计算奖金有关的逻辑不再放在Context中，而是分布在各个策略对象中
var strategies = {
"S": function( salary ){
return salary * 4;
},
"A": function( salary ){
return salary * 3;
},
"B": function( salary ){
return salary * 2;
}
};
var calculateBonus = function( level, salary ){
return strategies[ level ]( salary );
};
console.log( calculateBonus( 'S', 20000 ) ); // 输出：80000
console.log( calculateBonus( 'A', 10000 ) ); // 输出：30000
// 第三步 小球动起来
<body>
<div style="position:absolute; background:blue" id="div">我是div</div>
</body>
var tween = {
linear: function( t, b, c, d ){
return c*t/d + b;
},
easeIn: function( t, b, c, d ){
return c * ( t /= d ) * t + b;
},
strongEaseIn: function(t, b, c, d){
return c * ( t /= d ) * t * t * t * t + b;
},
strongEaseOut: function(t, b, c, d){
return c * ( ( t = t / d -1) * t * t * t * t + 1 ) + b;
},
sineaseIn: function( t, b, c, d ){
return c * ( t /= d) * t * t + b;
},
sineaseOut: function(t, b, c, d){
return c * ( ( t = t / d -1) * t * t + 1 ) + b;
}
};
var Animate = function( dom ){
this.dom = dom; // 进行运动的dom节点
this.startTime = 0; // 动画开始时间
this.startPos = 0; // 动画开始时，dom节点的位置，即dom的初始位置
this.endPos = 0; // 动画结束时，dom节点的位置，即dom的目标位置
this.propertyName = null; // dom节点需要被改变的css属性名
this.easing = null; // 缓动算法
this.duration = null; // 动画持续时间
};
Animate.prototype.start = function( propertyName, endPos, duration, easing ){
this.startTime = +new Date; // 动画启动时间
this.startPos = this.dom.getBoundingClientRect()[ propertyName ]; // dom节点初始位置
this.propertyName = propertyName; // dom节点需要被改变的CSS属性名
this.endPos = endPos; // dom节点目标位置
this.duration = duration; // 动画持续时间
this.easing = tween[ easing ]; // 缓动算法
var self = this;
var timeId = setInterval(function(){ // 启动定时器，开始执行动画
if ( self.step() === false ){ // 如果动画已结束，则清除定时器
clearInterval( timeId );
}
}, 19 );
};
Animate.prototype.step = function(){
var t = +new Date; // 取得当前时间
if ( t >= this.startTime + this.duration ){ // (1)
this.update( this.endPos ); // 更新小球的CSS属性值
return false;
}
var pos = this.easing( t - this.startTime, this.startPos,
this.endPos - this.startPos, this.duration );
// pos为小球当前位置
this.update( pos ); // 更新小球的CSS属性值
};
Animate.prototype.update = function( pos ){
this.dom.style[ this.propertyName ] = pos + 'px';
};
var div = document.getElementById( 'div' );
var animate = new Animate( div );
animate.start( 'left', 500, 1000, 'strongEaseOut' );
// animate.start( 'top', 1500, 500, 'strongEaseIn' );
// 第四步
// <form action="http:// xxx.com/register" id="registerForm" method="post">
// 请输入用户名：<input type="text" name="userName"/ >
// 请输入密码：<input type="text" name="password"/ >
// 请输入手机号码：<input type="text" name="phoneNumber"/ >
// <button>提交</button>
// </form>
/***********************策略对象**************************/
var strategies = {
isNonEmpty: function( value, errorMsg ){
if ( value === '' ){
return errorMsg;
}
},
minLength: function( value, length, errorMsg ){
if ( value.length < length ){
return errorMsg;
}
},
isMobile: function( value, errorMsg ){
if ( !/(^1[3|5|8][0-9]{9}$)/.test( value ) ){
return errorMsg;
}
}
};
/***********************Validator 类**************************/
var Validator = function(){
this.cache = [];
};
Validator.prototype.add = function( dom, rules ){
var self = this;
for ( var i = 0, rule; rule = rules[ i++ ]; ){
(function( rule ){
var strategyAry = rule.strategy.split( ':' );
var errorMsg = rule.errorMsg;
self.cache.push(function(){
var strategy = strategyAry.shift();
strategyAry.unshift( dom.value );
strategyAry.push( errorMsg );
return strategies[ strategy ].apply( dom, strategyAry );
});
})( rule )
}
};
Validator.prototype.start = function(){
for ( var i = 0, validatorFunc; validatorFunc = this.cache[ i++ ]; ){
var errorMsg = validatorFunc();
if ( errorMsg ){
return errorMsg;
}
}
};
/***********************客户调用代码**************************/
var registerForm = document.getElementById( 'registerForm' );
var validataFunc = function(){
var validator = new Validator();
validator.add( registerForm.userName, [{
strategy: 'isNonEmpty',
errorMsg: '用户名不能为空'
}, {
strategy: 'minLength:6',
errorMsg: '用户名长度不能小于10 位'
}]);
validator.add( registerForm.password, [{
strategy: 'minLength:6',
errorMsg: '密码长度不能小于6 位'
}]);
var errorMsg = validator.start();
return errorMsg;
}
registerForm.onsubmit = function(){
var errorMsg = validataFunc();
if ( errorMsg ){
alert ( errorMsg );
return false;
}
};