Does interpolation work in event bindng? - aurelia

Does interpolation work on event-binding? I tried the following without success:
<button type="button" click.delegate="${action}()">${action}</button>
action is a VM variable set to one of "edit","add","cancel". There exist VM functions: edit, add, and cancel.

I was having trouble trying to use interpolation with event-binding. I had much better luck referencing the VM as a function instead.
Say you had action as a property of your view model. You could set the value of that property to the correct method based on the model or some UI action, and then when the action is called as a method, the correct add/edit/cancel method is called.
inside the view-model (es6):
setAction(method) {
if(method === "edit") {
this.action = this.editMethod;
} else if(method === "add") {
this.action = this.addMethod;
} else {
this.action = this.cancelMethod;
}
}
editMethod() {
alert("edit");
}
addMethod() {
alert("add");
}
cancelMethod() {
alert("cancel/default");
}
inside the template:
<button click.delegate="setAction('edit')">Use Edit Method</button>
<button click.delegate="setAction('add')">Use Add Method</button>
<button click.delegate="setAction('cancel')">Use Cancel Method</button>
<button click.delegate="action()">action</button>

Jeremy Danyow provided the answer on the github issues forum for aurelia-binding.
<button click.delegate="$this[action]()">${action}</button>

Related

Vue class components dynamically add component depending on answer from backend

So from the backend I get a array of objects that look kind of like this
ItemsToAdd
{
Page: MemberPage
Feature: Search
Text: "Something to explain said feature"
}
So i match these values to enums in the frontend and then on for example the memberpage i do this check
private get itemsForPageFeatures(): ItemsToAdd[] {
return this.items.filter(
(f) =>
f.page== Pages.MemberPage &&
f.feature != null
);
}
What we get from the backend will change a lot over time and is only the same for weeks at most. So I would like to avoid to have to add the components in the template as it will become dead code fast and will become a huge thing to have to just go around and delete dead code. So preferably i would like to add it using a function and then for example for the search feature i would have a ref on the parent like
<SearchBox :ref="Features.Search" />
and in code just add elements where the ItemsToAdd objects Feature property match the ref
is this possible in Vue? things like appendChild and so on doesn't work in Vue but that is the closest thing i can think of to kind of what I want. This function would basically just loop through the itemsForPageFeatures and add the features belonging to the page it is run on.
For another example how the template looks
<template>
<div class="container-fluid mt-3">
<div
class="d-flex flex-row justify-content-between flex-wrap align-items-center"
>
<div class="d-align-self-end">
<SearchBox :ref="Features.Search" />
</div>
</div>
<MessagesFilter
:ref="Features.MessagesFilter"
/>
<DataChart
:ref="Features.DataChart"
/>
So say we got an answer from backend where it contains an object that has a feature property DataChart and another one with Search so now i would want components to be added under the DataChart component and the SearchBox component but not the messagesFilter one as we didnt get that from the backend. But then next week we change in backend so we no longer want to display the Search feature component under searchbox. so we only get the object with DataChart so then it should only render the DataChart one. So the solution would have to work without having to make changes to the frontend everytime we change what we want to display as the backend will only be database configs that dont require releases.
Closest i can come up with is this function that does not work for Vue as appendChild doesnt work there but to help with kind of what i imagine. So the component to be generated is known and will always be the same type of component. It is where it is to be placed that is the dynamic part.
private showTextBoxes() {
this.itemsForPageFeatures.forEach((element) => {
let el = this.$createElement(NewMinorFeatureTextBox, {
props: {
item: element,
},
});
var ref = `${element.feature}`
this.$refs.ref.appendChild(el);
});
}
You can use dynamic components for it. use it like this:
<component v-for="item in itemsForPageFeatures" :is="getComponent(item.Feature)" :key="item.Feature"/>
also inside your script:
export default {
data() {
return {
items: [
{
Page: "MemberPage",
Feature: "Search",
Text: "Something to explain said feature"
}
]
};
},
computed: {
itemsForPageFeatures() {
return this.items.filter(
f =>
f.Page === "MemberPage" &&
f.Feature != null
);
}
},
methods: {
getComponent(feature) {
switch (feature) {
case "Search":
return "search-box";
default:
return "";
}
}
}
};

Unable to set focus to a textarea, when the page loads

I am trying to set the focus on a syncfusion textarea but I am unable to do so. I have used the this.$nextTick when the component mounts as defined here but the system still does not focus on the textarea.
I have added the same "focus to textarea" code in the created event because somehow the created event is triggered after the mounted event.
I have re-created the issue here.
I also see that this.$refs.vocabularies.$el returns input#vocabularies.e-control.e-textbox.e-lib.
What am I doing wrong?
<template>
<ejs-textbox cssClass="height:500px;" id='vocabularies' :multiline="true" placeholder="Enter your vocabularies" floatLabelType="Auto" :input= "inputHandler" v-model="vocabularies" ref="vocabularies"/>
</template>
<script>
import '#syncfusion/ej2-base/styles/material.css';
import '#syncfusion/ej2-vue-inputs/styles/material.css';
export default
{
data() {
return {
vocabularies: '',
inputHandler: (args) =>
{
args.event.currentTarget.style.height = "auto";
args.event.currentTarget.style.height = (args.event.currentTarget.scrollHeight)+"px";
},
}
},
mounted()
{
this.$nextTick(function()
{
this.$refs.vocabularies.$el.style.height = "auto";
this.$refs.vocabularies.$el.style.height = (this.$refs.vocabularies.$el.scrollHeight)+"px";
this.$refs.vocabularies.$el.focus();
console.log(`mounted run`);
});
},
async created()
{
this.$nextTick(function()
{
this.$refs.vocabularies.$el.style.height = "auto";
this.$refs.vocabularies.$el.style.height = (this.$refs.vocabularies.$el.scrollHeight)+"px";
this.$refs.vocabularies.$el.focus();
console.log(`created run`);
});
},
</script>
So, here's how I've solved it. I am not so sure regarding how good of an approach this is as I haven't worked with syncfusion, so can't say if there might be a better way.
<ejs-textbox cssClass="test" id='vocabularies' :multiline="true" placeholder="Enter your vocabularies" floatLabelType="Auto" :input= "inputHandler" v-model="vocabularies" ref="vocabularies"/>
Then in mounted I did
mounted() {
let a = document.getElementsByClassName('test')[0];
a.children[1].focus();
}
I was able to fix the issue by using this.$refs.vocabularies.focusIn(); in the mounted() method, based on the documentation here
You can focus the text area by using the focusIn public method of the TextBox component in the created event. Kindly refer the below code,
<ejs-textbox cssClass="height:500px;" id='vocabularies' :multiline="true" placeholder="Enter your vocabularies" floatLabelType="Auto" :input= "inputHandler" v-model="vocabularies" ref="vocabularies" :created='onCreated' />
onCreated:function(){
this.$refs.vocabularies.ej2Instances.focusIn()
}
Please find the sample from the below link,
Sample Link:
https://www.syncfusion.com/downloads/support/directtrac/general/ze/quickstart1111977605

You may have an infinite update loop in a component render function using click event conditional rendering

I am rendering two texts based on a condition and be able to pass methods to the click event based on the condition. The default text is ADD TO COLLECTION because initially hasPaid property is false. Once payment has been made, I want to set that property to true
The function addToCollection first opens a modal, on the modal, the handlePayment function is implemented. I have been able to conditionally render the div to show either ADD TO COLLECTION or DOWNLOAD using v-on="". I also return hasPaid property from the handlePayment function.
<div class="float-right peexo-faded-text card-inner-text" :face="face" v-on="!hasPaid ? {click: addToCollection} : {click: handleDownload(face)}">
{{!hasPaid ? 'ADD TO COLLECTION': 'DOWNLOAD' }}
</div>
data: function () {
return {
hasPaid: false,
}
},
addToCollection(){
this.showcollectionModal = true;
},
handlePayment(){
this.showcollectionModal = false;
let accept = true;
this.showpaymentsuccessmodal = true;
//this.hasPaid = true;
return {
hasPaid: accept
}
},
I want to be able to set hasPaid property on the handlePayment function for the render function to pick it, so that the handleDownload function can then work.
The last section of this bit is going to be problematic:
v-on="!hasPaid ? {click: addToCollection} : {click: handleDownload(face)}"
When hasPaid is true it will invoke the method handleDownload immediately. That is, it will be called during render, not when the <div> is clicked.
You could fix it by 'wrapping' it in a function:
{click: () => handleDownload(face)}
I've used an arrow function in my example but you could use a normal function if you prefer.
Personally I wouldn't try to do this using the object form of v-on.
My first instinct is that you should consider just having two <div> elements and use v-if to decide which one is showing.
If you did want to use a single <div> I would put the click logic in a method. So:
<div class="..." :face="face" #click="onDivClick(face)">
Note that despite the apparent syntactic similarity to the way you defined your click listener this won't invoke the method immediately.
Then in the methods for the component:
methods: {
onDivClick (face) {
if (this.hasPaid) {
this.handleDownload(face)
} else {
this.addToCollection()
}
}
}

Vue Draggable with touch - drop doesn't trigger

I have been working on a website that has to function on both desktop and tablets. Part of the website is having three columns and being able to drag orders from column to column. Sometimes on drop, the user has to answer a few questions or change some of the data of that specific order. This happens in a pop-up window that is triggered by an #drop function (for example #drop="approved()". The method approved() then checks the status of the dropped order and shows the pop-up window).
When I am on desktop, everything works just fine. But when I switch to iPad Pro in the developer tools, nothing happens. I implemented Vue Draggable, which says to work with touch devices. In their examples I can't find anything about touch events or adding new handles for touch, so I don't know what to do now.
The dragging works just fine with touch devices, it's just the #drop function that doesn't trigger.
The dropzone (it includes a component that contains the draggables and a lot of if-statements):
<div class="col-md-4 border" #dragover.prevent #drop="approved()">
<Wachtrij class="fullHeight" :data2="opdrachtenData2"></Wachtrij>
</div>
The method:
export default {
methods: {
...
approved() {
console.log("Function approved() is being executed.")
if (this.draggingOrder.status === 5) {
this.popupGekeurd = true;
}
else if (this.draggingOrder.status === 6) {
this.popupTochGoed = true;
}
else if ([40, 52, 42,41,49,55,54].indexOf(this.draggingOrder.status) !== -1) {
this.back = true;
}
},
...
}
}
The problem seems to be that you are using native events, while the touch implementation does not (always?) use these events. It is intended that you use a draggable component with one of the events outlined in the documentation. In your case the start and end events look promising. This event has a few properties (docs), some of them being to and from.
Let's assume that we have the following code:
<draggable v-for="(zone, index) in zones" v-model="zones[index]" :class="['dropzone', `zone-${index}`]" :key="`dropzone-${index}`" :options="options" #start="start" #end="end">
<div v-for="item in zones[index]" class="dropitem" :key="`dropitem-${item.id}`">
{{ item.title }}
</div>
</draggable>
This creates a few zones, each filled with their own items. Each array item of zones is changed based on where you move each item. You can then use start to have information on when you start moving an item, and end to have information on when you stop moving an item, and where that item came from and where it ended up. The following methods show off what you can do with that in this case:
methods: {
start (event) {
console.log('start', event);
},
end (event) {
console.log('end', event);
const { from, to } = event;
if (to.className.match(/\bzone-2\b/)) {
console.log('Zone 2 has something added!')
}
if (from.className.match(/\bzone-0\b/)) {
console.log('Zone 0 had something removed!');
}
}
}
We make our dropzones with a class zone-0, zone-1 or zone-2 in this case, so we can use the class name to determine which dropzone we ended up in.
An alternative way to determine which zone was changed is to simply use a watcher. Since zones changes based on where you move items, you can simply watch a particular dropzone for changes and do things based on that.
watch: {
'zones.1': {
handler (oldZone, newZone) {
if (Array.isArray(oldZone) && Array.isArray(newZone) && oldZone.length !== newZone.length) {
console.log('Zone 1 was changed from', oldZone, 'to', newZone);
}
}
}
}
A full example can be found on codesandbox.

Set a variable inside a v-for loop on Vue JS

I have a v-for loop with vue.js on a SPA and I wonder if it's posible to set a variable at the beginning and then just print it everytime you need it, because right now i'm calling a method everytime i need to print the variable.
This is the JSON data.
{
"likes": ["famiglia", "ridere", "caffè", "cioccolato", "tres leches", "ballare", "cinema"],
"dislikes":["tristezze", "abuso su animali", "ingiustizie", "bugie"]
}
Then I use it in a loop:
<template>
<div class="c-interests__item" v-for="(value, key) in interests" :key="key" :data-key="key" :data-is="getEmotion(key)" >
// NOTE: I need to use the variable like this in different places, and I find myself calling getEmotion(key) everythime, is this the way to go on Vue? or there is another way to set a var and just call it where we need it?
<div :class="['c-card__frontTopBox', 'c-card__frontTopBox--' + getEmotion(key)]" ...
<svgicon :icon="getEmotion(key) ...
</div>
</template>
<script>
import interests from '../assets/json/interests.json'
... More imports
let emotion = ''
export default {
name: 'CInfographicsInterests',
components: {
JSubtitle, svgicon
},
data () {
return {
interests,
emotion
}
},
methods: {
getEmotion (key) {
let emotion = (key === 0) ? 'happy' : 'sad'
return emotion
}
}
}
</script>
// Not relevanty to the question
<style lang='scss'>
.c-interests{...}
</style>
I tried adding a prop like :testy="getEmotion(key)" and then { testy } with no luck...
I tried printing { emotion } directly and it doesn't work
So, there is anyway to acomplish this or should i stick calling the method every time?
Thanks in advance for any help.
It's not a good idea to use methods inside a template for non-user-directed actions (like onClicks). It's especially bad, when it comes to performance, inside loops.
Instead of using a method, you can use a computed variable to store the state like so
computed: {
emotions() {
return this.interests.map((index, key) => key === 0 ? 'happy' : 'sad');
}
}
This will create an array that will return the data you need, so you can use
<div class="c-interests__item"
v-for="(value, key) in interests"
:key="key" />`
which will reduce the amount of times the item gets re-drawn.