So I have an iron-list element for a user's data history. The iron-list is not part of a custom element. It is simply on the page. I want to populate once the user has successfully logged in. Perhaps it is just my inexperience with polymer, but there doesn't seem to be a straightforward way to do this. First attempt (simplified for reading, e.g. I don't actually use jquery, there's lots of error-handling code I'm omitting, etc):
<iron-list as="item" style='height: 100%;' id='history-list'>
<template>
<div style='min-height: 140px;'>
<ul>
<!-- various fields for each record as list items -->
</ul>
</div>
</template>
</iron-list>
<script>
//once user is logged in
var items = $.getJSON('userhistoryscript');
//setAttribute doesn't work either
document.getElementById('history-list').items = items;
</script>
I would swear this worked in an earlier version of Polymer. But it doesn't seem to work now, which is fine, but I need an alternative.
Some alternatives I've considered:
Have iron-ajax element in same DOM scope and set '
the URL once the user is logged in to trigger the
xhr request. I'm not sure whether or not that'd work.
Wrap the list in a custom element and use an
iron-meta-query per chrisW's answer.
Those options are terrible. I cannot believe there is no simpler way to accomplish this feat. How do I conditionally fetch data based on user input and dynamically add an iron-list to the page (or update one that's already there)? Is there really no API for this use case?
UPDATE
Thank you for your answers. Turns out that my original code actually works fine: it was actually a build process issue. For some reason iron-list did not get installed when I installed the project dependencies through bower. I took out the vulcanized import (which must not have contained a ref to iron-list either) and imported all the elements directly, then I got the 404 and figured out what had happened.
I think that for best practices, you should use this.$.historyList to refeer id on this element. Anyway, when you get data to populate iron-listyou should use this.set('items', data); An example using your element looks like:
<iron-list>
<template is="dom-repeat" items="{{data}}" as="history">
<!--history.property-->
</template>
</iron-list>
<script>
Polymer({
properties:{
data:{type:Array, value:[],}
},
_functionToSetDataWhenUserIsLoggedIn: function(data){
this.set('data',data);
}
});
</script>
Edit
An example of iron-list
<template is="dom-bind">
<iron-ajax url="data.json" last-response="{{data}}" auto></iron-ajax>
<iron-list items="[[data]]" as="item">
<template>
<div>
Name: <span>[[item.name]]</span>
</div>
</template>
</iron-list>
</template>
This example is using an ajax call that executes automatically and populates the iron-listwithout the need to create a customized element.
More about iron-list on:
https://elements.polymer-project.org/elements/iron-list
I didn't entirely understand your question. Hope this helps.
<iron-list items="[[data]]" as="item">
<template>
<div>
Name: <span>[[item.name]]</span>
</div>
</template>
</iron-list>
properties:{
data:{type:Array, value:[],}
},
// the attached function is automatically called
attached: function() {
// Use an iron meta in the element that you keep track in of login information
// or create an onLogin listener
var isLoggedIn = new Polymer.IronMetaQuery({key: 'isLoggedIn'}).value,
if (isLoggedIn) {
var jsonData = $.getJSON('userhistoryscript');
this.set('data',jsonData);
}
}
Side note, when access elements by ids in Polymer elements, make sure you do it this way:
this.$.elementId
or
Polymer.dom('#elementId')
Edit since you don't want to create a custom polymer element
Source Code
<template is="dom-bind">
<iron-list id="list">
</iron-list>
</template>
<script>
document.addEventListener('onLogin', function(event) {
var list = document.getElementById('#list');
var jsonDataObjects = $.getJSON('userhistoryscript');
for (var i = 0; i < jsonDataObjects.length; i++) {
var div = document.createElement('div');
div.textContent = jsonDataObjects[i].info; // change this line
list.appendChild(div);
}
});
</script>
Related
I tried adding it with like dropdownMenu.appendChild(menuItem) but as I expected this doesn't work. I couldn't find information about this on Polymer's guides nor other similar questions on here.
Is that possible? If so, how?
paper-dropdown-menu: https://elements.polymer-project.org/elements/paper-dropdown-menu
In Polymer, recommended way of manipulating the DOM is by manipulating the data:
put the list of menu items in array: var items_array = [....];
-create the menu as:
<paper-dropdown-menu label="Your favourite pastry">
<paper-listbox class="dropdown-content">
<template is="dom-repeat" items="{{items_array}}">
<paper-item>{{item}}</paper-item>
</template>
</paper-listbox>
</paper-dropdown-menu>
adding and removing elements in items_array will affect the menu immediately.
Found out the proper way from their docs:
Should select the Polymer element with: Polymer.dom(parent).querySelector(selector)
And append with: Polymer.dom(parent).appendChild(node)
I am new to web development and building an application using polymer 1.0.4. I am using the page.js routing similar to the example in start kit. Now many of the custom element that I built are using ajax and periodically refresh the data. The problem with page.js routing that It seems it loads all custom elements even if the element is not viewed by user. so all custom elements are loading the data even if it is not needed. my questions:
1- How could I fix this so the the elements load data only when they are viewed by the end users? Should I change the routing to another options like more-routing?
2- if the user filled the data in one custom element , then clicked on link to another element. The data will remains when the user goes back to the first custom element? How could I reset the polymer and html elements in the custom element when the use back to an old view?
Again, I'd recommend https://github.com/PolymerLabs/more-routing Eventually a 'carbon' (if I recall the name correctly) set of components will deal with this, according to the polymer summit videos, but until then this seems the standard approach.
Set up the pages via:
<more-routing-config driver="hash"></more-routing-config>
<more-route name="one" path="/one"></more-route>
<more-route path="/two">
<more-route name="two" path="/:name"></more-route>
</more-route>
Then the menu via:
<more-route-selector>
<paper-menu selected="0">
<paper-item route="{{urlFor('one')}}">One</paper-item>
<paper-item route="{{urlFor('two', {name: 'sup'})}}">Two</paper-item>
</paper-menu>
</more-route-selector>
And then the actual pages via:
<more-route-selector selectedParams="{{params}}">
<iron-pages selected="0">
<section route="one">
<div> Page one </div>
</section>
<section route="two">
<div> Page two: {{params.name}} </div>
</section>
</iron-pages>
</more-route-selector>
I used it when it was under the Polymore repository on github, and the samples above are from such, but it doesn't seem to have changed that much in its new home.
After you've set up the basics, listen for changes on the iron-pages, such as events that are available here. In such listeners, you can load the data for each section in iron-pages. One approach would be to use such listeners to call a method of a custom element, perhaps using a behaviour, that then brings down the data.
Try dna-router. You can create define states and routes in HTML only.
Setup routes by:
<dna-new-state state='home' route='/home'></dna-new-state>
<dna-new-state state='user' route='/user/:id/'></dna-new-state>
Create views by:
<dna-view
state='home'
element='home-template'></dna-view>
You can get all params inside your home-template polymer properties.
var params = this.params
For a detailed documentation, visit : https://github.com/Saquib764/dna-router
Firstly, the PolymerLabs/more-routing library is a nice alternative to page.js and is quite easy to implement. As this library is more declarative you can do things like:
routes.html
<more-routing-config driver="hash"></more-routing-config>
<more-route name="myRoute" path="/my-route-path/:id"></more-route>
app-element.html
<dom-module id="app-element">
<style>
iron-selector > * {
display: none;
}
iron-selector > .iron-selected {
display: block;
}
</style>
<template>
<more-route-selector>
<iron-selector>
<x-element></x-element>
</iron-selector>
</more-route-selector>
</template>
<script>Polymer({ ... });</script>
</dom-module>
x-element.html
<dom-module id="x-element">
<template>
<more-route id="route" context name="myRoute" params="{{params}}" active="{{activeRoute}}"></more-route>
</template>
<script>
Polymer({
is: 'x-element',
observers: [ '_paramsChanged(activeRoute, params.id)' ],
_paramsChanged: function(activeRoute) {
if (activeRoute) {
// Active route
} else {
// Inactive route
}
}
})
</script>
</dom-module>
Check out the polyfora app in the demo folder of the repository.
Otherwise, to use page.js I would consider:
Remove any auto iron-ajax queries in custom elements;
Pass a state attribute to custom elements;
Add an observer to any state changes within each custom element which triggers a function to run any iron-ajax queries.
As of Polymer 1.4, carbon-route (later renamed app-route) can be used:
https://github.com/polymerelements/carbon-route
https://blog.polymer-project.org/announcements/2016/03/28/carbon-route-released/
https://www.polymer-project.org/1.0/articles/routing.html
Here's an example taken from the polymer blog:
<carbon-location route="{{route}}">
</carbon-location>
<carbon-route route="{{route}}" pattern="/tabs/:tabName" data="{{data}}">
</carbon-route>
<paper-tabs selected="{{data.tabName}}" attr-for-selected="key">
<paper-tab key="foo">Foo</paper-tab>
<paper-tab key="bar">Bar</paper-tab>
<paper-tab key="baz">Baz!</paper-tab>
</paper-tabs>
<neon-animated-pages selected="{{data.tabName}}"
attr-for-selected="key"
entry-animation="slide-from-left-animation"
exit-animation="slide-right-animation">
<neon-animatable key="foo">Foo Page Here</neon-animatable>
<neon-animatable key="bar">Bar Page Goes Here</neon-animatable>
<neon-animatable key="baz">Baz Page, the Best One of the Three</neon-animatable>
</neon-animated-pages>
See also similar question: Polymer 1.0 - routing
I am using Polymer 1.0 and I am building a small accordion example. I have data binding to the accordion text fine, I just want to change the icon of the accordion when I click it.
Below is my code
<dom-module id="ab-accordion">
<template>
<iron-ajax
auto
handle-as="json"
on-response="handleResponse"
debounce-duration="300"
id="ajaxreq"></iron-ajax>
<template is="dom-repeat" id="accordion" items="{{items}}" as="item">
<div class="accordion" on-click="toggleParentAcc">
<div id="accordion_header" class="accordion__header is-collapsed">
<i class="icon icon--chevron-down"></i>
<span>{{item.name}}</span>
</div>
<div id="standard_accordion_body" class="accordion__body can-collapse">
<div class="accordion__content">
<content id="content"></content>
</div>
</div>
</div>
</template>
</template>
<script>
Polymer({
is: "ab-accordion",
//Properties for the Element
properties: {
accordian: Object,
childaccordions: Object,
// Param passed in from the element - Set if the accordion is open by default.
open: String,
data: String,
reqUrl: {
type: String,
value: "https://example.com/service.aspx"
},
},
ready: function () {
this.items = [];
},
attached: function () {
// Run once the element is attached to the DOM.
},
toggleParentAcc: function (event) { // Toggle the classes of the accordions
//This is where I want to toggle the class
this.$.accordion_header.classList.toggle('is-collapsed');
if (typeof event !== 'undefined') {
event.stopPropagation(); // Stop the click from going up to the parent.
}
},
handleResponse: function (e) {
this.items = e.detail.response.sports;
}
});
</script>
</dom-module>
Basically inside the toggleParentAcc function I want to toggle the class of the div with ID accordion_header. But I just get undefined or null.
I have tried the following two lines:
this.$.accordion_header // #1
this.$$('#accordion_header') // #2
How I access that element inside the dom-repeat?
UPDATE: I can't even access the elements within the when inside the attached function.
attached: function(){
this.$.accordion_header // This is null?!
this.$$('#accordion_header'); // this is also null!
}
https://www.polymer-project.org/1.0/docs/devguide/local-dom.html#node-finding
Note: Nodes created dynamically using data binding (including those in dom-repeat and dom-if templates) are not added to the this.$ hash. The hash includes only statically created local DOM nodes (that is, the nodes defined in the element’s outermost template).
I think it would be better if you'd use Polymer.dom(this.root) instead. Also I'd advice you to not use static IDs in dom-repeat as they are meant to be unique. Use classes instead.
Looks like you might be encountering Event Retargeting which happens when events "bubble" their way up the DOM tree. Read this documentation to learn more.
When I encountered this, I solved it by using something like:
var bar = Polymer.dom(event).path[2].getAttribute('data-foo');
inside my Polymer() function.
To figure it out in your case, you should go to the console and search the DOM tree / event log to locate your target. If you have trouble locating the correct area of the console, post a comment and I might be able to help further.
I eventually figured out a way of doing this without having to select elements in the nested template.
<template id="accord_template" is="dom-repeat" items="{{items}}" as="item">
<ab-accordion-row id="[[item.id]]" name="[[item.name]]" open="[[item.open]]">
</ab-accordion-row>
</template>
ab-accordion is another element, I just feed it the data and I can then change the classes based on the params.
<div id="accordion" class="accordion" on-click="toggleAccordion">
<div class$="{{getClassAccordionHeader(open)}}">
<i class="icon icon--chevron-down"></i>
<span>{{name}}</span>
</div>
<div id="standard_accordion_body" class$="{{getClassAccordionChild(open)}}">
<div class="accordion__content">
<content></content>
</div>
</div>
</div>
try with this.
toggleParentAcc: function (event) { // Toggle the classes of the accordions
//This is where I want to toggle the class
var header = event.target.parentElement;
Polymer.dom(header).classList.toggle('is-collapsed');
// rest of your code
}
I'm trying to build a simple memory card game in Meteor and I can't seem to create a grid of my cards to populate in html. I'm just trying to get a 4x4 grid for right now.
Here is the javascript:
Template.body.helpers({
cards: function() {
var allCards = Deck.find({}).fetch();
var chunks = [];
while (allCards.length > 0) {
chunks.push(allCards.slice(0, 4));
allCards = allCards.slice(4);
}
return chunks;
},
});
And here is the HTML:
<body>
<div class="container">
<div name="gameBoard">
{{#each cards}}
{{> cardsRow}}
{{/each}}
</div>
</div>
</body>
<template name="cardsRow">
<div class="row">
{{#each row}}
{{> card}}
{{/each}}
</div>
</template>
<template name="card">
<span class="text">{{text}}</span>
</template>
Right now I just have simple text entries in the db to see what I'm doing before I pull in images. I've tried console logging from my JS and I believe I'm creating the array of spliced rows correctly so I think the problem may be in the way I have arranged the markdown.
I tried pulling the each cards loop into a template as well instead of inside the body but I'm not sure how to render templates on demand. This is potentially an option since I have a new game button event listener that could call a render. I'm just not sure how to explicitly render in Meteor.
I tried following this previous post but I couldn't get it to work:
How do I populate a bootstrap grid system using handlebars for each command in Meteor.js?
Thoughts? I can provide more of my code base if needed.
Neither row in {{#each row}} in the "cardsRow" template, nor {{text}} in the "cards" template, refer the way that you hope they do. You need to define row and text as template helpers for each of these templates. In a template helper, this refers to the data object associated with the template.
In your case, when you iterate through #each cards in "container", this is passed into the "cardsRow" template as one of the chunks defined in your cards helper function. The helpers below should illustrate this, and are sufficient for your example.
Template.cardsRow.helpers({
row: function() {
console.log(this); // a chunk of cards
return this;
}
});
Template.card.helpers({
text: function() {
console.log(this); // a number in a chunk
return this;
}
});
I have no idea why is this happening!
i want to send an object to polymer element and then use it.
im using something like this for the element
<polymer-element name="post-thumb" attributes="post">
<template>
<article>
<span>this is a post thumb</span>
<h1>{{post.title}}</h1>
<p>{{post.body}}</p>
</article>
</template>
<script>
Polymer('post-thumb');
</script>
</polymer-element>
and after HTML import, i'm calling it like this:
<post-thumb post='{"title":"post title 1","body":"post body"}'> </post-thumb>
it's weird cause when i use {{post}} it'll bring back the whole {"title":"post title 1","body":"post body"} but when i use {{post.title}} polymer simply returns nothing!
what's wrong here!? :/
I think you need to hint to the polymer that the attribute is of object type, ie try
<script>
Polymer('post-thumb', {
created: function() {
this.post = {};
}
}
);
</script>