Develop Reference

Active events in vue instance encapsulated inside shadowDOM

I'm searching to trigger event from a vue instance which is encapsulated inside a shadowDOM.
For the moment, my code create a new Vue instance inside a shadowDOM and print the template without the style (because nuxt load the style inside the base vue instance).
I can call methods of each instance
But, when i'm trying to add an event / listener on my component, it doesn't work.
DOM.vue
<template>
<section ref='shadow'></section>
</template>
<script>
import bloc from '#/components/bloc.vue'
import Vue from 'vue'
export default {
data() {
return {
vm: {},
shadowRoot: {},
isShadowReady: false
}
},
watch: {
isShadowReady: function() {
let self = this
this.vm = new Vue({
el: self.shadowRoot,
components: { bloc },
template: "<bloc #click='listenClick'/>",
methods: {
listenClick() { console.log("I clicked !") },
callChild() { console.log("I'm the child !") }
},
created() {
this.callChild()
self.callParent()
}
})
}
},
mounted() {
const shadowDOM = this.$refs.shadow.attachShadow({ mode: 'open' })
this.shadowRoot = document.createElement('main')
shadowDOM.appendChild(this.shadowRoot)
this.isShadowReady = true
},
methods: {
callParent() {
console.log("I'am the parent")
},
}
}
</script>
bloc.vue
<template>
<div>
<p v-for='word in words' style='text-align: center; background: green;'>
{{ word }}
</p>
</div>
</template>
<script>
export default {
data() {
return {
words: [1,2,3,4,5,6]
}
}
}
</script>
Any idea ?
Thank you

Hi so after i watched at your code i think it's better to use the $emit to pass event from the child to the parent and i think it's more optimized then a #click.native
template: "<bloc #someevent='listenClick'/>",
<template>
<div #click="listenClickChild">
<p v-for='(word, idx) in words' :key="idx" style='text-align: center; background: green;'>
{{ word }}
</p>
</div>
</template>
<script>
export default {
data() {
return {
words: [1,2,3,4,5,6]
}
},
methods: {
listenClickChild() {
this.$emit('someevent', 'someValue')
}
}
}
</script>

bloc #click.native='listenClick'/>

Make a reactive component with vuejs

I need a Vue component to show some HTML content in v-data-table from Vuetify. I have seen this post Vue 2 contentEditable with v-model, and I created a similar code shown below.
My problem is the component is not reactive. When I click the "Test button", no content is updated in HtmlTextArea.
<template>
<div>
<v-btn #click="doTest()">Test Button</v-btn>
<HtmlTextArea
v-model="content"
style="max-height:50px;overflow-y: scroll;"
></HtmlTextArea>
</div>
<template>
export default {
name: "ModelosAtestados",
components: { HtmlTextArea },
data: () => ({
content: "",
}),
methods: {
doTest() {
this.content = "kjsadlkjkasfdkjdsjkl";
},
},
};
//component
<template>
<div ref="editable" contenteditable="false" v-on="listeners"></div>
</template>
<script>
export default {
name: "HtmlTextArea",
props: {
value: {
type: String,
default: "",
},
},
computed: {
listeners() {
return { ...this.$listeners, input: this.onInput };
},
},
mounted() {
this.$refs.editable.innerHTML = this.value;
},
methods: {
onInput(e) {
this.$emit("input", e.target.innerHTML);
},
},
};
</script>

This occurs because HtmlTextArea sets the div contents to its value prop only in the mounted lifecycle hook, which is not reactive.
The fix is to setup a watcher on value, so that the div contents are updated to match whenever a change occurs:
// HtmlTextArea.vue
export default {
watch: {
value: {
handler(value) {
this.$refs.editable.innerHTML = value;
}
}
}
}
demo

In the #click event binder, you have to pass a function. You passed the result of an executed function.
To make it work: #click="doTest" or #click="() => doTest()".
How to debug such problems:
Display the value you want to update on your template to check if its updated: {{content}}
Use the vue devtool extension to check the current state of your components

Onload method when the page is loading VUE

I want to call the method when the page is loading. So far I call the method when I click, but when I try to use mounted to automatically call the method, it keeps failing, do you have some suggestion?
Below is the code:
<template>
<div>
<AppHeader></AppHeader>
<div style="display: flex">
<ul>
<li
style="cursor: pointer"
v-for="exchange of profileExchanges"
:key="exchange.id"
#click="getImagesByExchange(exchange.id)"
>
<div style="padding: 20px; border: solid 2px red">
<h3>Brand: {{exchange.brand}}</h3>
<p>Description: {{exchange.description}}</p>
<p>Category: {{exchange.category}}</p>
</div>
</li>
</ul>
<div>
<span style="margin: 10px" v-for="url of exchangeImageUrls" :key="url">
<img width="250px" :src="url" />
</span>
</div>
</div>
<br />
</div>
</template>
<script>
import AppHeader from '#/components/Header5'
export default {
components: {
AppHeader
},
created() {
this.$store.dispatch('exchange/getExchangesByProfile', this.$store.state.auth.user.profile.user)
},
data() {
return {
selectedExchangeId: '',
exchanges: []
}
},
computed: {
user() {
return this.$store.state.auth.user
},
profile() {
return this.user.profile || {}
},
profileExchanges() {
return this.$store.getters['exchange/profileExchanges']
},
exchangeImageUrls() {
return this.$store.getters['exchange/imageUrls']
}
},
methods: {
getImagesByExchange(exchangeId) {
this.$store.dispatch('exchange/getImagesByExchange', exchangeId)
},
getListings() {
},
updateProfile(profile, closeModal) {
this.$store.dispatch('auth/updateProfile', profile)
.then(_ => {
closeModal()
})
}
}
}
</script>
I try to put mounted like this
mounted: function() {
this.getImagesByExchange() // Calls the method before page loads
},
But it keeps failing. I guess the problem is how to access the key, but not sure.

If the selectedExchangeId is already not set, you could get the first element of the profileExchanges array and pass the id to the getImagesByExchange function:
mounted() {
this.getImagesByExchange(this.profileExchanges[0].id) // Calls the method before page loads
},
EDIT
Looking again at your code one could suppose that, at the moment the component is mounted the profileExchanges property might not yet be set. One way to handle this is to call both of them inside the created like this:
async created() {
await this.$store.dispatch(
'exchange/getExchangesByProfile',
this.$store.state.auth.user.profile.user
);
if (this.profileExchanges && this.profileExchanges.length) {
this.getImagesByExchange(this.profileExchanges[0].id);
}
}

Dynamically changing props

On my app, I have multiple "upload" buttons and I want to display a spinner/loader for that specific button when a user clicks on it. After the upload is complete, I want to remove that spinner/loader.
I have the buttons nested within a component so on the file for the button, I'm receiving a prop from the parent and then storing that locally so the loader doesn't show up for all upload buttons. But when the value changes in the parent, the child is not getting the correct value of the prop.
App.vue:
<template>
<upload-button
:uploadComplete="uploadCompleteBoolean"
#startUpload="upload">
</upload-button>
</template>
<script>
data(){
return {
uploadCompleteBoolean: true
}
},
methods: {
upload(){
this.uploadCompleteBoolean = false
// do stuff to upload, then when finished,
this.uploadCompleteBoolean = true
}
</script>
Button.vue:
<template>
<button
#click="onClick">
<button>
</template>
<script>
props: {
uploadComplete: {
type: Boolean
}
data(){
return {
uploadingComplete: this.uploadComplete
}
},
methods: {
onClick(){
this.uploadingComplete = false
this.$emit('startUpload')
}
</script>

Fixed event name and prop name then it should work.
As Vue Guide: Custom EventName says, Vue recommend always use kebab-case for event names.
so you should use this.$emit('start-upload'), then in the template, uses <upload-button #start-upload="upload"> </upload-button>
As Vue Guide: Props says,
HTML attribute names are case-insensitive, so browsers will interpret
any uppercase characters as lowercase. That means when you’re using
in-DOM templates, camelCased prop names need to use their kebab-cased
(hyphen-delimited) equivalents
so change :uploadComplete="uploadCompleteBoolean" to :upload-complete="uploadCompleteBoolean"
Edit: Just noticed you mentioned data property=uploadingComplete.
It is easy fix, add one watch for props=uploadComplete.
Below is one simple demo:
Vue.config.productionTip = false
Vue.component('upload-button', {
template: `<div> <button #click="onClick">Upload for Data: {{uploadingComplete}} Props: {{uploadComplete}}</button>
</div>`,
props: {
uploadComplete: {
type: Boolean
}
},
data() {
return {
uploadingComplete: this.uploadComplete
}
},
watch: { // watch prop=uploadComplete, if change, sync to data property=uploadingComplete
uploadComplete: function (newVal) {
this.uploadingComplete = newVal
}
},
methods: {
onClick() {
this.uploadingComplete = false
this.$emit('start-upload')
}
}
})
new Vue({
el: '#app',
data() {
return {
uploadCompleteBoolean: true
}
},
methods: {
upload() {
this.uploadCompleteBoolean = false
// do stuff to upload, then when finished,
this.uploadCompleteBoolean = true
},
changeStatus() {
this.uploadCompleteBoolean = !this.uploadCompleteBoolean
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js"></script>
<div id="app">
<button #click="changeStatus()">Toggle Status {{uploadCompleteBoolean}}</button>
<p>Status: {{uploadCompleteBoolean}}</p>
<upload-button :upload-complete="uploadCompleteBoolean" #start-upload="upload">
</upload-button>
</div>

The UploadButton component shouldn't have uploadingComplete as local state (data); this just complicates the component since you're trying to mix the uploadComplete prop and uploadingComplete data.
The visibility of the spinner should be driven by the parent component through the prop, the button itself should not be responsible for controlling the visibility of the spinner through local state in response to clicks of the button.
Just do something like this:
Vue.component('upload-button', {
template: '#upload-button',
props: ['uploading'],
});
new Vue({
el: '#app',
data: {
uploading1: false,
uploading2: false,
},
methods: {
upload1() {
this.uploading1 = true;
setTimeout(() => this.uploading1 = false, Math.random() * 1000);
},
upload2() {
this.uploading2 = true;
setTimeout(() => this.uploading2 = false, Math.random() * 1000);
},
},
});
<script src="https://rawgit.com/vuejs/vue/dev/dist/vue.js"></script>
<div id="app">
<upload-button :uploading="uploading1" #click="upload1">Upload 1</upload-button>
<upload-button :uploading="uploading2" #click="upload2">Upload 2</upload-button>
</div>
<template id="upload-button">
<button #click="$emit('click')">
<template v-if="uploading">Uploading...</template>
<slot v-else></slot>
</button>
</template>

Your question seems little bit ambiguë, You can use watch in that props object inside the child component like this:
watch:{
uploadComplete:{
handler(val){
//val gives you the updated value
}, deep:true
},
}
by adding deep to true it will watch for nested properties in that object, if one of properties changed you ll receive the new prop from val variable
for more information : https://v2.vuejs.org/v2/api/#vm-watch
if not what you wanted, i made a real quick example,
check it out hope this helps : https://jsfiddle.net/K_Younes/64d8mbs1/

Can't get method to execute on parent component from child component

I'm trying to get a method to execute on a parent component when a button in one of its child components is clicked. I am using single file components with Webpack. Here's the code for the child component:
<template>
<button v-on:click="add">Click</button>
</template>
<script>
export default {
methods: {
add: () => {
console.log('foo')
this.$dispatch('addClick')
}
}
}
</script>
And the code for the parent:
<template>
<div id="app">
<count :total="total"></count>
<click></click>
</div>
</template>
<script>
import count from './components/count.vue'
import click from './components/click.vue'
export default {
components: {
count,
click
},
data: () => {
return {
total: 0
}
},
methods: {
addToTotal: () => {
console.log('bar')
this.total += 1
}
},
events: {
addClick: 'addToTotal'
}
}
</script>
The count component is just an h1 element that displays the total variable. When I click the button, "foo" logs to the console, but "bar" does not and the total doesn't change. Any ideas on what I'm doing wrong? Thanks in advance!

You are using lambda notation for your methods, which is giving them the wrong this. If you use function instead, it will work.
Vue.component('click', {
template: '#clicker',
methods: {
add: function() {
console.log('foo')
this.$dispatch('addClick')
}
}
})
new Vue({
el: '#app',
data: () => {
return {
total: 0
}
},
methods: {
addToTotal: function () {
console.log('bar')
this.total += 1
}
},
events: {
addClick: 'addToTotal'
}
});
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/1.0.26/vue.min.js"></script>
<template id="clicker">
<button v-on:click="add">Click</button>
</template>
<div id="app">
<count :total="total"></count>
<click></click>
{{total}}
</div>

Use two-way .sync binding type modifier on total property of count component so that the value will be updated when parent total value is changed. Here is an example:
Vue.component('click', {
template: '<button v-on:click="add">Click</button>',
methods: {
add: function () {
this.$dispatch('addClick');
}
}
});
Vue.component('count', {
template: '<h1 v-text="total"></h1>',
props: {
total: {
type: Number,
twoWay: true
}
}
});
new Vue({
el: '#app',
data: {
total: 1
},
methods: {
addTotal: function () {
this.total++;
}
},
events: {
addClick: 'addTotal'
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/1.0.25/vue.min.js"></script>
<div id="app">
<count :total.sync="total"></count>
<click></click>
</div>