Goal
I'm wanting to use a toggle to filter (or hide via dom-if) elements based on the toggle itself and a boolean property of the element.
So with an array of objects:
[{..., active: true}, {..., active: false}]
I want to hide the "active:false" objects with the toggle.
Problem
I can't figure out how to get the if function "_showAlert(item)" to fire on toggle switch or more importantly if this is even the way I should go about this using Polymer. I'd appreciate guidance on either.
<paper-toggle-button checked="{{activeOnly}}">Active Only</paper-toggle-button>
<paper-listbox>
<template is="dom-repeat" items="[[alerts]]">
<template is="dom-if" if="{{_showAlert(item)}}">
<paper-item>...</paper-item>
</template>
</template>
</paper-listbox>
<script>
(function() {
'use strict';
Polymer({
is: 'alert-list',
properties: {
alerts: {
type: Array
},
activeOnly: {
type: Boolean,
notify: true
}
},
ready: function(){
this.alerts = [{..., active: true}, {..., active: false}];
},
_showAlert: function(item) {
// The alert item will have a boolean property called "active"
return (item.active || !this.activeOnly);
}
})
})();
</script>
I've just appended some data in the ready function for now for development purposes. I can get the list to display just fine and I can verify the binding between the toggle and the "activeOnly" property is working.
Thanks!
I assume you would want your showAlert function to re-evaluate every time either item.active or activeOnly change. To achieve that you have to pass them to the funciton as arguments (also see docs).
<template is="dom-if" if="{{_showAlert(item.active, activeOnly)}}">
Related
This is a Vue.js and Vuex related problem.
I'm building an aplication where I show a list of residences (ul -> li -> a) while at the same time showing those illustrations' position in an illustration, solved via SVG (active elements are path and polygon). If it was just the one element I could do show active state using only css, but because there are two active elements at the same time I need an event.
Previously I solved the issue by giving the residence, stored in Vuex, a hasFocus: false value, which I would change to true on mouseenter/focus and back to false on mouseout/focusout. With that I can add/remove a class has-focus to which I add the active state css. I have now redone the datastore to use Vuex ORM, after which I'm seeing worse frame rate drops when carying out the mutation.
Is there a better way of doing this than using a value in a Vuex (ORM) object model?
Some code:
In Vuex:
residences: [
{
id: 1,
hasFocus: false,
[…] // Other values, not relevant to this question
},
{
id: 2,
hasFocus: false
},
…
…
],
In ResidenceItem.vue:
<router-link
[…]
v-bind:class="{
'has-focus': residence.hasFocus === true,
}"
#mouseenter.native.stop="toggleFocus(true)"
#mouseout.native.stop="toggleFocus(false)"
#focus.native.stop="toggleFocus(true)"
#focusout.native.stop="toggleFocus(false)"
[…]
>
// Content
</router-link>
[…]
props: {
id: {
required: true,
},
},
methods: {
toggleFocus(focus) {
Residence.update({
where: this.id,
data: {
hasFocus: focus,
},
});
},
},
why should "hasFocus" be stored in vuex? is there a need to be?
if not, you should move it to ResidenceItem.vue's data().
i think it is a just temporary state on vue.
<router-link
:class="{
'has-focus': focused,
}"
#mouseenter.native.stop="focused = true"
#mouseout.native.stop="focused = false"
#focus.native.stop="focused = true"
#focusout.native.stop="focused = false"
[…]
>
...
data() {
return {
focused: false,
};
},
...
if hasFocus is needed in vuex (which i think it is a bad idea), you should use normal vuex state to store like focusedResidenceId: null.
I can provide more detail explanation if you need. Please let me know if you so.
I've been trying to work this out but sofar have been unable to find an answer. My Polymer element loads a base template JSON file, which is then run through a dom-repeat to create a basic HTML page.
Then another JSON text-file is loaded, which completes the various areas of the HTML with a JS function.
Upon button-click form child, a function is run that triggers the loading of another JSON file that adds additional info. This all works fine.
But when I go out of the page and back in it, it has remembered all my settings but does not display things correctly. It displays the translatedText well and the html code is there, but it does not complete the html code for the originalText.
It seems to want to load the last JSON file before the DOM is properly rendered. So I want it to refresh the whole DOM, but how do I do this?
My MWE:
<template>
<iron-ajax
auto
url="basetext.json"
handle-as="json"
last-response="{{baseText}}"></iron-ajax>
<div class="textcontent">
<template is="dom-repeat" items="{{baseText.lines}}" as="line">
<div class="lineblock">
<div class="line" id="line{{line.lineid}}" inner-h-t-m-l="{{line.linetext}}"></div>
<template is="dom-if" if="[[extraShowEnabled]]">
<div class="linepi" id='linepi{{line.lineid}}' inner-h-t-m-l="{{line.linetext}}"></div>
</template>
</div>
</template>
</div>
<template is="dom-if" if="[[extraLoadEnabled]]">
<iron-ajax
auto
url="originaltext.json"
handle-as="json"
last-response="{{originalText}}"></iron-ajax>
</template>
<iron-ajax
auto
url="translatedtext.json"
handle-as="json"
last-response="{{translatedText}}"></iron-ajax>
</template>
<script>
Polymer({
is: 'text-page',
properties: {
translatedText: Object,
originalText: Object,
extraShowEnabled: {
type: Boolean,
value: false
},
extraLoadEnabled: {
type: Boolean,
value: false
},
showViewer: {
type: String,
value: "none"
}
},
observers: [
'setView(showViewer)',
' _computeSegments(translatedText,".line")',
' _computeSegments(originalText,".linepi")'
],
ready: function() {
this.addEventListener('eventFromChild', this.changeView);
},
changeView: function(event) {
this.showViewer = event.detail.selectedView;
},
setView: function(showViewer) {
\\ first some code here to reset all css.
if (showViewer === "none") {
this.extraShowEnabled = false;
this.extraLoadEnabled = false;
}
if (showViewer === "sidebyside") {
this.extraShowEnabled = true;
this.extraLoadEnabled = true;
this._computeSegments(this.originalText,".linepi");
this._addSideBySideCode();
}
},
_computeSegments: function(inputText,linetype) {
if (inputText) {
Array.from(this.querySelectorAll(linetype+" sc-segment")).forEach(item => item.innerHTML = inputText.segments[item.id]);
}
},
_addSideBySideCode: function() {
\\ this function just adds some css.
},
});
</script>
I think You should try to use a compute function result as a dom-repeat item source, something like this:
<template is="dom-repeat" items="{{itmesByParamsCompute(baseText, originalText, translatedText, extraloadEnabled, ...)}}" as="line">
Add as many params as You need to recompute on. Then that compute function should return a valid source anytime at least one of the paras changes.
Also keep in mind, that if any of these params will become undefined that compute function might be ignored completely. Work around for this is making this opposite way - one property which is modified from manny observers, something like this:
properties: {
items_to_use: {
type: Array,
value: []
},
translatedText: {
type: Object,
observer: 'updateItemsToUse'
},
originalText: {
type: Object,
observer: 'updateItemsToUse'
}
},
updateItemsToUse: function (data) {
let updatedArray = this.someMixFixFunction(this.item_to_use, data);
this.set('items_to_use', updatedArray);
},
someMixFixFunction: function (old_array, data_to_apply) {
// do some merging or what ever You need here, for example
let updatedArray = old_array.concat(data_to_apply);
return updatedArray;
}
I am trying to use the Polymer templatizer to create a single instance of a template, append it into a div and get data binding to work between the host and this instance but am having difficulty getting this to work.
The most simple example I have tried:
HTML
<dom-module id="test-app">
<paper-input label="host" value="{{test}}"></paper-input>
<template id="template">
<paper-input label="instance" value="{{test}}"></paper-input>
</template>
<div id="placehere"></div>
</dom-module>
JS
Polymer({
is: "test-app",
behaviors: [Polymer.Templatizer],
properties: {
test: {
type: String,
value: 'hello',
notify: true,
},
},
ready: function() {
this.templatize(this.$.template);
var clone = this.stamp({test: this.test});
Polymer.dom(this.$.placehere).appendChild(clone.root);
},
});
The idea above is to create the instance of the template, place it into "placehere" and have the two input text boxes keep in sync.
When the page loads, the instance is created successfully and the value in both textboxes is "hello" but changing either input box does nothing.
The documentation on the polymer page seems a bit lightweight:
https://www.polymer-project.org/1.0/docs/api/Polymer.Templatizer
but it mentions the use of _forwardParentProp and _forwardParentPath. How exactly am I supposed to implement them in my situation?
As you have already figured out, you need to implement some of the Templatizer's methods. Particularly the _forwardParentProp and _forwardParentPath methods.
But before I begin, I must also point out one additional error in your custom elements definition. In your dom-module element, you have the element's contents defined without the template. It is essential to wrap everything within a template element. The fixed version of your custom element would be like this:
<dom-module id="test-app">
<template>
<paper-input label="host" value="{{test}}"></paper-input>
<template id="template">
<paper-input label="instance" value="{{test}}"></paper-input>
</template>
<div id="placehere"></div>
</template>
</dom-module>
As for the implementation of the Templatizer methods, you first need to store the stamped instance. After that, both methods that need implementations are more or less simple one-liners.
Here is the full JavaScript part of the custom element:
Polymer({
is: "test-app",
behaviors: [Polymer.Templatizer],
properties: {
test: {
type: String,
value: 'hello',
notify: true,
},
},
ready: function() {
this.templatize(this.$.template);
var clone = this.stamp({test: this.test});
this.stamped = clone.root.querySelector('*'); // This line is new
Polymer.dom(this.$.placehere).appendChild(clone.root);
},
// This method is new
_forwardParentProp: function(prop, value) {
if (this.stamped) {
this.stamped._templateInstance[prop] = value;
}
},
// This method is new
_forwardParentPath: function(path, value) {
if (this.stamped) {
this.stamped._templateInstance.notifyPath(path, value, true);
}
},
});
Here is a working JSBin demo: http://jsbin.com/saketemehi/1/edit?html,js,output
Very new to Polymer and Polymerfire. I couldn't find an answer here so hoping I can get help here. The basic question I have is "how do I work with the data that polymerfire/firebase-query sends?" Note I'm using polymerfire version 0.9.4, and polymer is version 1.4.0.
I can load my data from Firebase no problem using Firebase query, however some of the values are raw numbers that I need to convert to user friendly information. For example I have time stored in ms that I want to convert to a date, and a numeric field that indicates the "type" of data that is stored and I want to show an icon for it, not just a raw number. I figured my best option would be to use the transactions-complete promise or an observer. Both fire but neither seems to give me access to the data. The Observer's newData is an empty array, and transactions-complete.. well I don't really know what to do with that when the promise fires. Below is my relevant code. I also tried using notify: true, but I seem to not be grasping the concept correctly.
<firebase-query
id="query"
app-name="data"
path="/dataPath"
transactions-complete="transactionCompleted"
data="{{data}}">
</firebase-query>
<template is="dom-repeat" items="{{data}}">
<div class="card">
<div>Title: <span>{{item.title}}</span></div>
<div>Date Created: <span>{{item.dateCreated}})</span></div>
<div>Date Modified: <span>{{item.dateModified}}</span></div>
<div>Status: <span>{{item.status}}</span></div>
</div>
</template>
Polymer({
is: 'my-view1',
properties: {
data: {
notify: true,
type: Object,
observer: 'dataChanged'
}
},
dataChanged: function (newData, oldData) {
console.log(newData[0]);
// do something when the query returns values?
},
transactionCompleted: new Promise(function(resolve, reject) {
// how can I access "data" here?
})`
I wound up going another way entirely, which seemed to be a cleaner approach to what I was doing anyways. I broke it down into separate components. This way when the detail component was loaded, the ready function would allow me to adjust the data before it got displayed:
list.html:
<firebase-query
id="query"
app-name="data"
path="/dataPath"
data="{{data}}">
</firebase-query>
<template is="dom-repeat" items="{{data}}">
<my-details dataItem={{item}}></my-details>
</template>
details.html
<template>
<div id="details">
<paper-card heading="{{item.title}}">
<div class="card-content">
<span id="description">{{item.description}}</span><br/><br/>
<div class="details">Date Created: <span id="dateCreated">{{item.dateCreated}}</span><br/></div>
<div class="details">Last Modified: <span id="dateModified">{{item.dateModified}}</span><br/></div>
<div class="status"><span id="status">{{item.status}}</span><br/></div>
</div>
</paper-card>
</template>
Then in the javascript ready function I can intercept and adjust the data accordingly:
Polymer({
is: 'my-details',
properties: {
item: {
notify: true,
},
},
ready: function() {
this.$.dateModified.textContent = this.getDate(this.item.dateModified);
this.$.dateCreated.textContent = this.getDate(this.item.dateCreated);
this.$.status.textContent = this.getStatus(this.item.status);
},
Try the following changes:
Take out the transactions-completed attribute - it is only relevant when the query is updating data to Firebase
Change the dom-repeat template to get it's items attribute from convertedData - this allows you to do the data conversions to## Heading ## the results of the firebase-query
<firebase-query
id="query"
app-name="data"
path="/dataPath"
data="{{data}}">
</firebase-query>
<template is="dom-repeat" items="{{convertedData}}">
<div class="card">
<div>Title: <span>{{item.title}}</span></div>
<div>Date Created: <span>{{item.dateCreated}})</span></div>
<div>Date Modified: <span>{{item.dateModified}}</span></div>
<div>Status: <span>{{item.status}}</span></div>
</div>
</template>
Add a convertedData property to do your data conversions from data which has the raw data
Change the observer syntax as per the example. This sets up the observer to to observe for changes to deep property values which results in the observer method being fired - see: https://www.polymer-project.org/1.0/docs/devguide/observers#deep-observation
In the observer method you can populate the convertedData object from the data object which should then render the content
Polymer({
is: 'my-view1',
properties: {
data: {
notify: true,
type: Object
},
convertedData: {
notify: true,
type: Object
}
},
// observer syntax to monitor for deep changes on "data"
observers: [
'dataChanged(data.*)'
]
dataChanged: function (newData, oldData) {
console.log(newData);
// convert the "newData" object to the "convertedData" object
}
}
My returned data is an array of objects with a nested object. I'm unable to display the 'events' in a v-for loop in my template as I cannot seem to access that part of the returned data.
The data is returned like this (from Vue DevTools):
list: Object
user: "name"
id: "id"
events: Array[3]
0: Object
title: "event 1"
1: Object
title: "event 2"
2: Object
title: "event 3"
Using Vue-resource (via CDN) how do I get display just the events in my template?
Template:
<template id="events-template">
<div v-for="events in list">
#{{events.title}}
</div>
</template>
My application:
Vue.component('events', {
template: '#events-template',
data: function() {
return {
list: []
}
},
created: function() {
this.fetchEventsList();
},
methods: {
fetchEventsList: function() {
this.$http.get('events', function(events) {
this.list = events;
}).bind(this);
}
}
});
Ok it seems you try to access the false properties in your loop.
the list variable does not contain a list/array (object). The array you want to iterate is the events attribute of the list object. so list.events
Furthermore you want to access the property (title) of the "current" item (event) in the loop. Then you don't have to access to the hole array but rather to the current element. event.title
Replace your template block:
<template id="events-template">
<div v-for="event in list.events">
#{{event.title}}
</div>
</template>