我一直在尝试克隆 polymer 元素——通常是从某种数据创建的元素，因此不能只使用构造函数或 document.createElement 创建模板的新实例。 .
element.cloneNode不能单独工作，因为它不复制影子根 lodash由 Polymer Clone Objects 提议似乎什么也没做(克隆对象为空)cloneEl.shadowRoot.innerHTML = sourceEl.shadowRoot.innerHTML;复制 shadow-root，但似乎失去了绑定(bind) 扩展示例:http://jsbin.com/vitumuwayu/3/edit
有没有
Polymer.cloneNode我一直找不到的功能？
最佳答案
我终于找到了这个问题的答案(至少对于 Polymer 1.0)。
https://stackoverflow.com/a/6620327/1878199显示如何复制属性。
https://stackoverflow.com/a/25187164/1878199描述了如何获取 polymer 元素的属性列表。
那么答案是:
newElement = element.cloneNode(true);
for(var i in element.properties) {
newElement[i] = element[i]
}
完整的图解和工作示例 on jsbin或在下面的片段中。
<!DOCTYPE html>
<html>
<head>
<link rel="import" href="https://cdn.rawgit.com/download/polymer-cdn/1.0.1/lib/polymer/polymer.html">
<meta charset="utf-8">
<title>Polymer Cloning Example</title>
</head>
<dom-module id="custom-element">
<template>
<div style="border: solid">
<input type="text" name="some_string" value="{{boundvalue::input}}">
<p>{{boundvalue}}</p>
</div>
</template>
<script>
Polymer({
is: 'custom-element',
properties: {
boundvalue: {
type: String,
value: 'Enter some text...',
notify: true
}
}
});
</script>
</dom-module>
<body>
<custom-element id="source-element"></custom-element>
<p>
<button onclick="cloneElementWithoutProperties()">1 Clone the above element into the list below</button>
<p></p>
<button onclick="cloneElementWithProperties()">2 Clone the above element into the list below and also copy properties</button>
<p></p>
<h3>Test Description</h3>
<ol>
<li>Modify text above</li>
<li>Click Button 1</li>
<p></p>
<p>Observed: An element is added below, but it is reset to the original text ('Enter some text...')</p>
<li>Click Button 2</li>
<p></p>
<p>Observed: An element is added below, and it keeps the modified text</p>
<p>Also verify that the functionality is still ok: Modify the input in the copy, the text is also updated</p>
</ol>
<h3>List of cloned elements:</h3>
<div id='list-elements'>
</div>
</body>
</html>
<script>
function cloneElementWithProperties() {
list = document.querySelector("#list-elements");
sourceEl = document.querySelector("#source-element")
cloneEl = sourceEl.cloneNode(true);
for (var i in sourceEl.properties) {
cloneEl[i] = sourceEl[i];
}
list.insertBefore(cloneEl, null);
}
function cloneElementWithoutProperties() {
list = document.querySelector("#list-elements");
sourceEl = document.querySelector("#source-element")
cloneEl = sourceEl.cloneNode(true);
list.insertBefore(cloneEl, null);
}
</script>关于polymer - 克隆 polymer 元素的正确方法是什么？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30005682/