Lov*_*ess 1 javascript polymer
我在普通的Polymer Elements中加载Javascript时遇到问题:
这是在没有聚合物的情况下执行时完美无缺的测试代码:
<body>
<style>
#content {background-color: #f2f2f2;}
#button {padding: 10px 20px;}
</style>
<div id="content">
<h1 id="title">Title</h1>
<p>This example uses the addEventListener() method to attach a click event to the document.</p>
<button id="button">Testbutton</button>
</div>
<script>
function popup2() {
alert("What's up brow?");
console.log("deine mudda");
};
var button = document.getElementById("button");
button.addEventListener("click", popup2, false);
</script>
</script>
</body>
但是我想在Polymer Elements中使用Javascript并尝试以下插入:
NR.1:脚本标签内的Javascript,在模板标签之后:
<polymer-element name="my-element">
<template>
<style>
#content {background-color: #f2f2f2;}
#button {padding: 10px 20px;}
</style>
<div id="content">
<h1 id="title">Title</h1>
<p>This example uses the addEventListener() method to attach a click event to the document.</p>
<button id="button">Testbutton</button>
</div>
</template>
<script>
Polymer('my-element', {
popup: function() {
alert('What the... dude?');
},
var button = document.getElementById("button");
button.addEventListener("click", popup, false);
});
</script>
</polymer-element>
这不起作用.我在firefox中收到错误消息:"SyntaxError:missing:在属性id之后.Chrome改为:"SyntaxError:Unexpected Identifier".
两者都指向"var button = document.getelementById("button")行;
根据Polymer Documentation,javascript应该放在文件的末尾:https: //www.polymer-project.org/docs/start/tutorial/step-1.html
所以在第二次尝试中,我将我的Javascript直接放在模板标签中,如下所示:
<polymer-element name="my-element">
<template>
<style>
#content {background-color: #f2f2f2;}
#button {padding: 10px 20px;}
</style>
<div id="content">
<h1 id="title">Title</h1>
<p>This example uses the addEventListener() method to attach a click event to the document.</p>
<button id="button">Testbutton</button>
</div>
<script>
function popup() {
alert("jajaja");
};
var button = document.getElementById("button");
button.addEventListener("click", popup, false);
</script>
</template>
<script>
Polymer('my-element', {
});
</script>
</polymer-element>
但这次我得到:"未捕获的TypeError:无法读取属性'addEventListener'的null",它将agian指向我写的行:"button.addEventListener("click",popup,false);".
我想这意味着,编译器无法看到按钮ID,因为它在Shadow-Dom中？
请指导我.
<polymer-element name="my-element">
<template>
<style>
#content {background-color: #f2f2f2;}
#button {padding: 10px 20px;}
</style>
<div id="content">
<h1 id="title">Title</h1>
<p>This example uses the addEventListener() method to attach a click event to the document.</p>
<button on-tap="{{popup}}">Testbutton</button>
</div>
</template>
<script>
Polymer('my-element', {
popup: function() {
alert('alert');
}
});
</script>
</polymer-element>
在聚合物元素中,您可以使用on-tap ="{{function}}"属性直接绑定到函数.
编辑:所有代码都没有进入阻止
在js方法中保留eventlisteners
<polymer-element name="my-element">
<template>
<style>
#content {background-color: #f2f2f2;}
#button {padding: 10px 20px;}
</style>
<div id="content">
<h1 id="title">Title</h1>
<p>This example uses the addEventListener() method to attach a click event to the document.</p>
<button id="button">Testbutton</button>
</div>
</template>
<script>
Polymer('my-element', {
ready: function () {
var button = this.$.button;
button.addEventListener("click", function () {
alert('alert');
});
}
});
</script>
</polymer-element>
再次编辑:OP希望将HTML与JS分开
再编辑1次:我认为如果不使用声明性方法,使用匿名函数是最简单的方法.代码编辑