案例：当select 下拉选择框值变化时，显示其值（不是文本）
常规写法
<h3>JavaScript no MVC</h3>
<div>
<select name="" id="setAnimal">
<option value="cat">cat</option>
<option value="fish">fish</option>
<option value="bird">bird</option>
</select>
<p id="animalAction"></p>
</div>
<script type="text/javascript">
var animal = document.getElementById('setAnimal');
console.dir(animal);
animal.onchange = function() {
var action = null;
switch (this.value) {
case 'cat':
action = 'cat meows';
break;
case 'fish':
action = 'fish swim';
break;
case 'bird':
action = 'bird fly';
break;
default:
action = 'unknow';
}
console.log(action);
document.getElementById('animalAction').innerHTML = action;
};
</script>
MVC 写法
<h3>javascript simple MVC</h3>
<div>
<select name="" id="setAnimal">
<option value="cat">cat</option>
<option value="fish">fish</option>
<option value="bird">bird</option>
</select>
</div>
<p id="animalDo"></p>
<script>
// controller
Animal = {
start : function() {
this.view.start();//从视图触发
},
set : function(animalName) {
this.model.setAnimal(animalName);
//controller 改变 model
}
};
// model
Animal.model = {
animalDictionary : {
car : 'meows',
fish : 'swims',
bird : 'flies'
},
currentAnimal : null,
setAnimal : function(name) {
this.currentAnimal = this.animalDictionary[name] ? name : null;
this.onchange();
},
onchange : function() {
Animal.view.update();
//model传递结果到View(个人觉得这里可以由Controller来专递，最好不要直接操作视图)
},
getAnimalAction : function() {
return this.currentAnimal ? this.currentAnimal + ' ' + this.animalDictionary[this.currentAnimal] : 'unknow';
}
};
// view
Animal.view = {
start : function() {
document.getElementById('setAnimal').onchange = this.onchange;
//视图绑定事件
},
onchange : function() {
Animal.set(document.getElementById('setAnimal').value);
//视图执行操作，调用Controller
},
update : function() {
//视图执行最后的更新响应
console.log(Animal.model.getAnimalAction());
document.getElementById('animalDo').innerHTML = Animal.model.getAnimalAction();
}
};
Animal.start();//入口
</script>