I am working on this issue for 6 hours now and I seem to be unable to see it.
So here is the snippet from the index.html:
<flat-data-array availableModes="{{modes}}" id="dataArray"></flat-data-array>
<flat-strip-view availableModes="{{modes}}" id="flatViewer"></flat-strip-view>
the dataArray (which works always fine):
<link rel="import" href="../../bower_components/polymer/polymer.html">
<dom-module id="flat-data-array">
<script>
(function() {
'use strict';
Polymer({
is: 'flat-data-array',
properties: {
strips: {
type: Array,
notify: true,
observe: '_stripsChanged'
},
availableModes: {
type: Number,
notify: true,
observe: '_modesChanged'
},
socket: {
type: Object
}
}
,
_stripsChanged: function(newVal, oldVal) {
this.fire('flat-strip-array-changed',{ newValue: newVal, oldValalue: oldVal});
},
_modesChanged: function(newVal, oldVal) {
this.fire('flat-strip-mode-changed',{ newValue: newVal, oldValalue: oldVal});
alert("Changed");
},
ready: function() {
this.socket = io.connect('http://192.168.0.101:3000');
socket.on('flatCommand', function(data) {
console.log(data);
});
this.availableModes=15;
/*[
{
modeID: 65,
letter: "A",
name: "Singler Color"
}
];*/
}
});
})();
</script>
</dom-module>
and now the problem:
<link rel="import" href="../../bower_components/polymer/polymer.html">
<link rel="import" href="../../elements/flat-list/flat-list.html">
<dom-module id="flat-strip-view">
<template>
<style>
:host {
display: block;
}
</style>
<flat-list
strips="{{strips}}"
id="flatList"
>
</flat-list>
</template>
<script>
(function() {
'use strict';
Polymer({
is: 'flat-strip-view',
properties: {
strips: {
type: Array,
notify: true,
observer: '_flatStripChanged'
},
availableModes: {
type: Number,
notify: false,
observer: '_flatModeChanged'
}
}
,
_flatModeChanged: function(newVal, oldVal) {
this.fire('flat-strip-view-mode-changed',{ newValue: newVal, oldValalue: oldVal});
alert("Event");
},
_flatStripChanged(newVal, oldVal) {
this.fire('flat-strip-view-array-changed',{ newValue: newVal, oldValalue: oldVal});
}
});
})();
</script>
</dom-module>
due to the definition in the index.html I'd expect the availableModes to be the same in both elements. But if i type:
documtent.getElementById('dataArray').availableModes
I get 15 (perfectly ok), but when I type
document.getElementById('flatViewer').availableModes it says undefined
Oddly enough, had another definition in the same manner before (infact I only removed it to track down the problem) and that worked and passed the values down to the last element in the cain. I just can't see any difference.
<aiur-data-array strips="{{mystrips}}" availableModes="{{modes}}" id="dataArray"></aiur-data-array>
<aiur-strip-view availableModes="{{modes}}" strips="{{mystrips}}" id="aiurViewer"></aiur-strip-view>
That worked for "strips" in any direction with any element...
Change the attribute availableModes to available-modes.
When mapping attribute names to property names:
Attribute names are converted to lowercase property names. For example, the attribute firstName maps to firstname.
Attribute names with dashes are converted to camelCase property names by capitalizing the character following each dash, then removing the dashes. For example, the attribute first-name maps to firstName.
Souce: https://www.polymer-project.org/1.0/docs/devguide/properties.html#property-name-mapping
So I have this Polymer element with dom-repeat. It binds correctly. However, when the array is modified, it doesn't reflect back to DOM. Nothing changed when I click on the button.
<dom-module id="my-element">
<template>
<template is="dom-repeat" id="allRules" items="{{allRules}}">
<span class="tag" rule-enabled$={{item.enabled}}>{{item.name}}</span>
</template>
<button on-click="click">Click me</button>
</template>
</dom-module>
<script>
Polymer({
is: "my-element",
properties: {
allRules: {
type: Array,
notify: true
}
},
click: function() {
this.allRules[0].name = "three";
},
ready: function() {
this.allRules = [
{
name: "one",
enabled: true
}, {
name: "two",
enabled: false
}
]
},
setBind: function(bind) {
this.bind = bind;
}
});
</script>
Is there a method like notifyArrayUpdated to tell the DOM to update binding data?
When you change a subproperty inside an array, you need to do
this.set('allRules.0.name', 'three');
Check out array binding for details.
Here is a plunker for it.
In Polymer 0.5 the advice on globals was as outlined in this question/answer:
Polymer global variables
However in Polymer 1.0 this doesn't seem to work. Change notifications are not automatically generated on the underlying model, they are generated on the <dom-module> instead which means that change notifications will be generated on only one of the <app-globals>.
What is the recommended way of implementing this pattern in Polymer 1.0?
Polymer element <iron-meta> is also an option. For me this was the easiest solution.
I've extended Etherealones' solution to work as a Behavior, and to extend Polymers "set" and "notifyPath" methods to trigger the updates automatically. This is as close as i could get to a true databinding across components/elements:
globals-behavior.html:
<script>
var instances = [];
var dataGlobal = {};
var GlobalsBehaviour = {
properties: {
globals: {
type: Object,
notify: true,
value: dataGlobal
}
},
ready: function() {
var _setOrig = this.set;
var _notifyPathOrig = this.notifyPath;
this.set = function() {
_setOrig.apply(this, arguments);
if (arguments[0].split(".")[0] === "globals") {
this.invokeInstances(_notifyPathOrig, arguments);
}
};
this.notifyPath = function(path, value) {
_notifyPathOrig.apply(this, arguments);
if (arguments[0].split(".")[0] === "globals") {
this.invokeInstances(_notifyPathOrig, arguments);
}
};
},
invokeInstances: function(fn, args) {
var i;
for (i = 0; i < instances.length; i++) {
instance = instances[i];
if (instance !== this) {
fn.apply(instance, args);
}
}
},
attached: function() {
instances.push(this);
},
detached: function() {
var i;
i = instances.indexOf(this);
if (i >= 0) {
instances.splice(i, 1);
}
}
};
</script>
And in all polymer elements that should have access to the globals variable:
<script>
Polymer({
is: 'globals-enabled-element',
behaviors: [GlobalsBehaviour]
});
</script>
Examples:
I have posted a full example as a Gist on Github
Here's a snippet to see it in action:
<!DOCTYPE html>
<html>
<head>
<title>Globals Behavior Example</title>
<link rel="import" href="//rawgit.com/Polymer/polymer/master/polymer.html">
<dom-module id="globals-enabled-element">
<template>
<input type="text" value="{{globals.my_variable::input}}">
</template>
<script>
var instances = [];
var dataGlobal = {};
var GlobalsBehaviour = {
properties: {
globals: {
type: Object,
notify: true,
value: dataGlobal
}
},
ready: function() {
var _setOrig = this.set;
var _notifyPathOrig = this.notifyPath;
this.set = function() {
_setOrig.apply(this, arguments);
if (arguments[0].split(".")[0] === "globals") {
this.invokeInstances(_notifyPathOrig, arguments);
}
};
this.notifyPath = function(path, value) {
_notifyPathOrig.apply(this, arguments);
if (arguments[0].split(".")[0] === "globals") {
this.invokeInstances(_notifyPathOrig, arguments);
}
};
},
invokeInstances: function(fn, args) {
var i;
for (i = 0; i < instances.length; i++) {
instance = instances[i];
if (instance !== this) {
fn.apply(instance, args);
}
}
},
attached: function() {
instances.push(this);
},
detached: function() {
var i;
i = instances.indexOf(this);
if (i >= 0) {
instances.splice(i, 1);
}
}
};
</script>
<script>
Polymer({
is: 'globals-enabled-element',
behaviors: [GlobalsBehaviour]
});
</script>
</dom-module>
</head>
<body>
<template is="dom-bind">
<p>This is our first polymer element:</p>
<globals-enabled-element id="element1"></globals-enabled-element>
<p>And this is another one:</p>
<globals-enabled-element id="element2"></globals-enabled-element>
</template>
</body>
</html>
I have implemented a pattern like iron-signals uses for this purpose. So the basic principle is that you manually notify other instances when an update occurs.
Consider this:
<dom-module id="x-global">
<script>
(function() {
var instances = [];
var dataGlobal = {};
Polymer({
is: 'x-global',
properties: {
data: {
type: Object,
value: dataGlobal,
},
},
attached: function() {
instances.push(this);
},
detached: function() {
var i = instances.indexOf(this);
if (i >= 0) {
instances.splice(i, 1);
}
},
set_: function(path, value) {
this.set(path, value);
instances.forEach(function(instance) {
if (instance !== this) { // if it is not this one
instance.notifyPath(path, value);
}
}.bind(this));
},
notifyPath_: function(path, value) {
instances.forEach(function(instance) {
instance.notifyPath(path, value);
});
},
fire_: function(name, d) {
instances.forEach(function(instance) {
instance.fire(name, d);
});
},
});
})();
</script>
</dom-module>
You will simple call the version that have an underscore suffix like fire_ when you are firing an event. You can even create a Polymer Behavior of some sort with this pattern I guess.
Beware that preceding underscore properties are already used by Polymer so don't go ahead and convert these to _fire.
P.S.:
I didn't look around to solve how to reflect the notification of this.push(array, value); as I don't need it. I don't know if it's possible this way. Should go find Polymer.Base.push.
Sjmiles, one of Polymer's creators just posted the following snippet to the Polymer slack room as an example of shared data:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="description" content="shared-data element and repeats">
<base href="http://milestech.net/components/">
<script href="webcomponentsjs/webcomponents-lite.min.js"></script>
<link href="polymer/polymer.html" rel="import">
</head>
<body>
<demo-test></demo-test>
<script>
(function() {
var private_data = [{name: 'a'}, {name: 'b'}, {name: 'c'}];
Polymer({
is: 'private-shared-data',
properties: {
data: {
type: Object,
notify: true,
value: function() {
return private_data;
}
}
}
});
})();
Polymer({
is: 'xh-api-device',
properties: {
data: {
type: Array,
notify: true
},
_share: {
value: document.createElement('private-shared-data')
}
},
observers: [
'dataChanged(data.*)'
],
ready: function() {
this.data = this._share.data;
this.listen(this._share, 'data-changed', 'sharedDataChanged');
},
dataChanged: function(info) {
this._share.fire('data-changed', info, {bubbles: false});
},
sharedDataChanged: function(e) {
this.fire(e.type, e.detail);
},
add: function(name) {
this.push('data', {name: name});
}
});
</script>
<dom-module id="demo-test">
<template>
<h2>One</h2>
<xh-api-device id="devices" data="{{data}}"></xh-api-device>
<template is="dom-repeat" items="{{data}}">
<div>name: <span>{{item.name}}</span></div>
</template>
<h2>Two</h2>
<xh-api-device data="{{data2}}"></xh-api-device>
<template is="dom-repeat" items="{{data2}}">
<div>name: <span>{{item.name}}</span></div>
</template>
<br>
<br>
<button on-click="populate">Populate</button>
</template>
<script>
Polymer({
populate: function() {
this.$.devices.add((Math.random()*100).toFixed(2));
// this works too
//this.push('data', {name: (Math.random()*100).toFixed(2)});
}
});
</script>
</dom-module>
</body>
</html>
I've actually moved my app to using simple data binding, so I'm not sure of the validity of this approach, but maybe it would be useful to someone.
I have tried to improve on Alexei Volkov's answer, but I wanted to define the global variables separately. Instead of the getters/setters I used the observer property and saved the key together with the instances.
The usage is:
<app-data key="fName" data="{{firstName}}" ></app-data>
whereas the keyproperty defines the name of the global variable.
So for example you can use:
<!-- Output element -->
<dom-module id="output-element" >
<template>
<app-data key="fName" data="{{data1}}" ></app-data>
<app-data key="lName" data="{{data2}}" ></app-data>
<h4>Output-Element</h4>
<div>First Name: <span>{{data1}}</span></div>
<div>Last Name: <span>{{data2}}</span></div>
</template>
</dom-module>
<script>Polymer({is:'output-element'});</script>
Definition of the <app-data>dom module:
<dom-module id="app-data"></dom-module>
<script>
(function () {
var instances = [];
var vars = Object.create(Polymer.Base);
Polymer({
is: 'app-data',
properties: {
data: {
type: Object,
value: '',
notify: true,
readonly: false,
observer: '_data_changed'
},
key: String
},
created: function () {
key = this.getAttribute('key');
if (!key){
console.log(this);
throw('app-data element requires key');
}
instances.push({key:key, instance:this});
},
detached: function () {
key = this.getAttribute('key');
var i = instances.indexOf({key:key, instance:this});
if (i >= 0) {
instances.splice(i, 1);
}
},
_data_changed: function (newvalue, oldvalue) {
key = this.getAttribute('key');
if (!key){
throw('_data_changed: app-data element requires key');
}
vars.set(key, newvalue);
// notify the instances with the correct key
for (var i = 0; i < instances.length; i++)
{
if(instances[i].key == key)
{
instances[i].instance.notifyPath('data', newvalue);
}
}
}
});
})();
</script>
Fully working demo is here: http://jsbin.com/femaceyusa/1/edit?html,output
I've combined all suggestions above into the following global polymer object
<dom-module id="app-data">
</dom-module>
<script>
(function () {
var instances = [];
var vars = Object.create(Polymer.Base);
var commondata = {
get loader() {
return vars.get("loader");
},
set loader(v) {
return setGlob("loader", v);
}
};
function setGlob(path, v) {
if (vars.get(path) != v) {
vars.set(path, v);
for (var i = 0; i < instances.length; i++) {
instances[i].notifyPath("data." + path, v);
}
}
return v;
}
Polymer({
is: 'app-data',
properties: {
data: {
type: Object,
value: commondata,
notify: true,
readonly: true
}
},
created: function () {
instances.push(this);
},
detached: function () {
var i = instances.indexOf(this);
if (i >= 0) {
instances.splice(i, 1);
}
}
});
})();
</script>
and use it elsewere like
<dom-module id="app-navigation">
<style>
</style>
<template>
<app-data id="data01" data="{{data1}}" ></app-data>
<app-data id="data02" data="{{data2}}"></app-data>
<span>{{data1.loader}}</span>
<span>{{data2.loader}}</span>
</template>
</dom-module>
<script>
(function () {
Polymer({
is: 'app-navigation',
properties: {
},
ready: function () {
this.data1.loader=51;
}
});
})();
</script>
Changing either data1.loader or data2.loader affects other instances. You should to extend commondata object to add more global properties like it shown with loader property.
It is much easier to achieve the same effect of global variables if you wrapped your application in a template. Watch the explanation in this video (I linked to the exact minute and second where the concept is explained).
Using ootwch's solution, I ran into a race condition situation with lazy-loaded components.
As posted, lazy-loaded components are not initialized with the value from the shared data.
In case anyone else runs into the same problem, I think I fixed it by adding a ready callback like this:
ready: function() {
const key = this.getAttribute('key')
if (!key) {
throw new Error('cm-app-global element requires key')
}
const val = vars.get(key)
if (!!val) {
this.set('data', val)
}
},
Hope this saves someone some pain.
I am trying to select an element by id that was created dynamically:
<dom-module id="filter-box">
<style>
:host {
display: block;
}
</style>
<template>
<h4 id="title">{{title}}</h4>
<paper-checkbox id="test">test</paper-checkbox><br>
<template is="dom-repeat" items="{{filters}}">
<paper-checkbox id="{{item}}">{{item}}</paper-checkbox><br>
</template>
</template>
</dom-module>
<script>
(function () {
Polymer({
is: 'filter-box',
properties: {
filters: {
type: Array,
notify: true,
},
title: {
type: String
}
},
ready: function() {
this.filters = [
'Commercial',
'Enterprise'
];
},
isSelected: function(filter) {
return this.$$[filter].checked;
}
});
})();
</script>
When isSelected("something") is called I get:
"Uncaught TypeError: Cannot read property 'checked' of undefined"
I can select the title via this.$.title, however I can not select the dynamic elements this way or using this.$$ as suggested here.
According the reference you provided you are supposed to call this.$$(selector) with parentheses as in a function call (and not with brackets). So replace your code with this:
return this.$$('#'+filter).checked;
Note that you may also need to prepend the id selector with #.
I have three nested polymer elements. Each of them has default values, which may be overridden with published value.
But i can't do it.
On create event does not exist published value. On ready event child element has already ready and not updated.
I made example js-bin.
In reality, each element in the separate file. It is example.
Object.assign - es6 method for merging objects (use es6-shim).
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
<script src="//cdnjs.cloudflare.com/ajax/libs/es6-shim/0.18.0/es6-shim.js"></script>
<script src="http://www.polymer-project.org/components/platform/platform.js"></script>
<link href="http://www.polymer-project.org/components/polymer/polymer.html" rel="import">
</head>
<body unresolved>
<polymer-element name="my-field" attributes="ask">
<template>
<span><content></content> Message: {{message}}</span>
</template>
<script>
(function() {
Polymer('my-field', {
defaultAsk: { message: "Hello from Field!" },
created: function() {
console.log('created-field', this.ask, this.message);
Object.assign(this, this.defaultAsk);
},
ready: function() {
console.log('ready-field', this.ask, this.message);
Object.assign(this, this.ask);
}
});
})();
</script>
</polymer-element>
<polymer-element name="my-shelf" attributes="ask">
<template>
<my-field ask="{{field}}"><content></content></my-field>
</template>
<script>
(function() {
Polymer('my-shelf', {
defaultAsk: { field: { message: "Hello from Shelf!" } },
created: function() {
console.log('created-shelf', this.ask, this.field);
Object.assign(this, this.defaultAsk);
},
ready: function() {
console.log('ready-shelf', this.ask, this.field);
Object.assign(this, this.ask);
}
});
})();
</script>
</polymer-element>
<polymer-element name="my-cabinet">
<template>
<my-shelf ask="{{shelf}}"><content></content></my-shelf>
</template>
<script>
(function() {
Polymer('my-cabinet', {
ask: { shelf: { field: { message: "Hello from outside!" } } },
defaultAsk: { shelf: { field: { message: "Hello from Cabinet!" } } },
created: function() {
console.log('created-cabinet', this.ask, this.shelf);
Object.assign(this, this.defaultAsk);
},
ready: function() {
console.log('ready-cabinet', this.ask, this.shelf);
Object.assign(this, this.ask);
}
});
})();
</script>
</polymer-element>
<my-cabinet>Yo!</my-cabinet>
</body>
</html>
All will working as I want, if use only one object through many nested elements.
Example on js-bin
All my element extended of other one (my-elem) only for remove doubled code and make my example more readable. ask - binding data (from my-cabinet to my-field). Click - changing data.
Unfortunately, on jsbin wery uneasy console for view fired messages.
I made small schema of chain events with nested elements. Maybe, it will help someone.
p.s. Don't kick me for my bad english.