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In the below example, how do I bind the
obj.namevariable of the<input>field in<test-element2>to<test-element>?
Below is my code. I have two polymer elements. test-element has the data binded to obj.name. test-element2 has an input field which is observed by the function objChanged. Whatever value I change in the input field it changes and prints in test-element2 but the change isn't reflected in test-element. Can any body help get the value reflected to test-element1? I have a solution using this.fire("object-change") for when the text changes but I am looking for a solution without using event listeners.
One more thing is that I need to create an element from the script and it cannot be hardcoded in the HTML DOM.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Demo</title>
<script src="../../bower_components/webcomponentsjs/webcomponents-lite.js"></script>
<link rel="import" href="../../bower_components/polymer/polymer.html"/>
</head>
<body>
<dom-module id="test-element">
<template>
<div>Hello <span>{{obj.name}}</span></div>
</template>
<script>
TestElement = Polymer({
is: "test-element",
properties: {
"obj": {
type: Object,
notify: true
}
},
observers: [
"objChanged(obj.name)"
],
"objChanged": function() {
var that = this;
console.log("First element in 1",that.obj);
}
});
</script>
</dom-module>
<dom-module id="test-element2">
<template>
<input value="{{obj.name::input}}"/>
</template>
<script>
Polymer({
is: "test-element2",
properties: {
"obj": {
type: Object,
notify: true,
value: {
"name": "Charlie"
}
}
},
observers: [
"objChanged(obj.name)"
],
ready: function() {
var element = new TestElement();
element.set("obj", this.obj);
this.appendChild(element);
},
"objChanged": function() {
console.log("changed in test-element2:", this.obj);
}
});
</script>
</dom-module>
<test-element2></test-element2>
</body>
</html>
473
If you include <test-element> in the <template> of test-element2 you can avoid using event listeners or observers. In this way test-element2 handles the data binding between the input and <test-element> for you.
Below is a live working example that maintains the obj property as you have set it up in your elements.
<script src="http://www.polymer-project.org/1.0/samples/components/webcomponentsjs/webcomponents.min.js"></script>
<link rel="import" href="http://www.polymer-project.org/1.0/samples/components/polymer/polymer.html">
<dom-module id="test-element">
<template>
<div>Hello <span>[[obj.name]]</span>
</div>
</template>
<script>
TestElement = Polymer({
is: "test-element",
properties: {
"obj": {
type: Object,
notify: true
}
}
});
</script>
</dom-module>
<dom-module id="test-element2">
<template>
<input value="{{obj.name::input}}" />
<test-element obj="[[obj]]"></test-element>
</template>
<script>
Polymer({
is: "test-element2",
properties: {
"obj": {
type: Object,
notify: true,
value: {
"name": "Charlie"
}
}
}
});
</script>
</dom-module>
<test-element2></test-element2>Currently, imperative data-binding is not supported in Polymer 1.0 outside of <template is="dom-bind">.
I would recommend setting up observers like the example below or adjusting your requirements to include <test-element> in test-element2.
button {
display: block;
}<script src="http://www.polymer-project.org/1.0/samples/components/webcomponentsjs/webcomponents.min.js"></script>
<link rel="import" href="http://www.polymer-project.org/1.0/samples/components/polymer/polymer.html">
<dom-module id="test-element">
<template>
<div>Hello <span>[[obj.name]]</span>
</div>
</template>
<script>
TestElement = Polymer({
is: "test-element",
properties: {
obj: {
type: Object,
notify: true
}
}
});
</script>
</dom-module>
<dom-module id="test-element2">
<template>
<input value="{{obj.name::input}}" />
</template>
<script>
Polymer({
is: "test-element2",
properties: {
obj: {
type: Object,
notify: true,
value: {
"name": "Charlie"
}
}
},
observers: ["objNameChanged(obj.name)"],
objNameChanged: function(newValue) {
Polymer.dom(document).querySelectorAll("test-element").forEach(function(element) {
element.notifyPath("obj.name", newValue);
});
Polymer.dom(this.root).querySelectorAll("test-element").forEach(function(element) {
element.notifyPath("obj.name", newValue);
});
}
});
</script>
</dom-module>
<test-element2></test-element2>
<button>Add test-element to <em>test-element2</em>
</button>
<button>Add test-element to <em>body</em>
</button>
<script>
var testElement2 = document.querySelector("test-element2");
var createTestElement = function(insertPoint) {
var testElement = new TestElement();
testElement.notifyPath("obj.name", testElement2.obj.name);
insertPoint.appendChild(testElement);
};
document.querySelector("button:nth-of-type(2)").addEventListener("click", function() {
createTestElement(Polymer.dom(document).querySelector("body"));
});
document.querySelector("button").addEventListener("click", function() {
createTestElement(Polymer.dom(testElement2.root));
});
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