在我的测试中，我有3个从主要html文件导入的元素:
<html><head><title>my-app</title>
<script src="bower_components/webcomponentsjs/webcomponents.min.js"></script>
<link rel="import" href="elements/app-globals.html">
<link rel="import" href="/Polymer/my-app/elements/my-categories.html">
<link rel="import" href="/Polymer/my-app/elements/my-items.html">
</head>
<body>
<my-categories></my-categories>
<my-items></my-items>
</body>
</html>
“app-globals.html”为:
<link rel="import" href="../bower_components/polymer/polymer.html">
<polymer-element name="app-globals" attributes="data selectedCategoryId selectedItemId">
<script>
(function() {
var values = {};
Polymer('app-globals', {
ready: function() {
console.log("app-globals -> ready");
this.values = values;
console.dir(this.values);
},
});
})();
</script>
</polymer-element>
'my-categories.html':
<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="/Polymer/my-app/elements/app-globals.html">
<polymer-element name="my-categories">
<template>
<app-globals id="globals"></app-globals>
<div>selectedCategoryId = {{$.globals.values.selectedCategoryId}}</div>
<ul>
<template repeat="{{category in categories}}">
<li class="li-category" data-_id="{{category._id}}" on-tap="{{selectCategory}}">{{category.name}}</li>
</template>
</ul>
</template>
<script>
Polymer('my-categories', {
values: {},
ready: function() {
var HOST = 'xxx.yyy.zzz.www';
var PORT = '8888';
this.categories = <loaded from websocket>;
},
selectCategory: function(event, detail, sender) {
var elt = (event.target.nodeName == 'INPUT')? event.target.parentNode : event.target;
this.values.selectedCategoryId = elt.dataset._id;
this.$.globals.values.selectedCategoryId = elt.dataset._id;
return false;
}
});
</script>
</polymer-element>
在这里，当单击li元素之一时，“selectedCategoryId”被更新。
此值通过全局变量传递到最后一个元素“my-items.html”:
<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="/Polymer/my-app/elements/app-globals.html">
<polymer-element name="my-items">
<template>
<app-globals id="globals"></app-globals>
<style>
</style>
<div >selectedCategoryId = {{$.globals.values.selectedCategoryId}}</div>
<ul>
<template repeat="{{item in items}}"
on-category-tap="{{handleCategoryTap}}">
<li class="li-item" data-_id="{{item._id}}" on-click="{{selectItem}}">{{item.title}}</li>
</template>
</ul>
</template>
<script>
Polymer('my-items', {
values: {},
ready: function() {
var HOST = 'xxx.yyy.zzz.www';
var PORT = '8888';
console.log("'my-items' -> this.$.globals.values:");
console.dir(this.$.globals.values);
for(var prop in this.$.globals.values) {
if(this.$.globals.values.hasOwnProperty(prop)) {
console.log("this.$.globals.values[" + prop + "] = " + this.$.globals.values[prop] + "");
}
}
console.log("'my-items' -> this.$.globals.values.selectedCategoryId = " + this.$.globals.values.selectedCategoryId);
},
handleCategoryTap: function(event) {...,
selectItem: function(event) {...}
return false;
} });
</script>
导致我有些奇怪:
console.dir(this。$。globals.values)给我正确的响应:
目的 {
selectedCategoryId:“547dfb6578be56f6630041a8”
}
但是，选择此属性“selectedCategoryId”会导致:
console.log(“'my-items'-> this。$。globals.values.selectedCategoryId =” + this。$。globals.values.selectedCategoryId);
给我:
'my-items'-> this。$。globals.values.selectedCategoryId = undefined
不确定为什么？
最佳答案
我建议您使用:https://github.com/akc42/akc-meta
我确实使用它来通过本地数据绑定(bind)在整个DOM中共享信息!
如果需要工作示例，请参见我的项目:https://github.com/MeTaNoV/firebase-element-extended
关于polymer - Polymer Globals认为有些奇怪，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27378605/