I have an audio player component that needs to send a message to all other players to pause themselves when it is clicked. However, there's a variable amount of components all inside of a v-for loop. It looks something like this:
<template>
<AudioPlayer v-for="song in songs" :key="song.id" #play="pauseOthers" />
</template>
<script>
import { defineComponent, ref } from 'vue';
import AudioPlayer from '#/components/AudioPlayer.vue';
export default defineComponent({
setup(){
var songs = [{id: "song1"},{id: "song2"}]
const pauseOthers = () => {
//this is the part that I need to figure out
}
return { songs, pauseOthers }
}
})
</script>
The components's script looks like
<script>
import { defineComponent, ref } from 'vue';
export default defineComponent({
setup(){
const pause = () => {
console.log("Paused!");
}
return { pause }
}
})
</script>
Ideally this could avoid using third-party packages, but it's fine if there really is no easy way.
Basically what you are going to want to do is create a a ref on the component which contains the v-for loop (i.e. the parent component) that is something like const currentlyPlayingPlayerIndex = ref(-1) then provide that as a prop to your AudioPlayer component. In AudioPlayer you use a watcher that watches for the value of that prop to change, if the index of that player (order in the v-for list) matches the value of currentlyPlayingPlayerIndex then take whatever action is required to play the audio. If it doesn't match, take whatever action is required to pause the audio. This will ensure that only one player is ever playing at once.
Within the player component the "pause" button should emit an event that sets the value of currentlyPlayingPlayerIndex to -1 or null or something that is outside the bounds of the range of the indexes. The "play" button should emit an event to the parent that updates the value of currentlyPlayingPlayerIndex to the index of the player component that contained the clicked button.
In summary, don't manage the "playing" state on the level of player but instead on their parent.
I agree with #WillD, you should manage those events from the parent or you will overcomplicate it.
Example:
<!-- Parent -->
<template>
<AudioPlayer v-for="song in songs" :key="song.id" :song-id="song.id" #play="pauseOthers" />
</template>
<script lang="ts" setup>
const songs = [
{ id: "song1" },
{ id: "song2" },
{ id: "song3" },
{ id: "song4" },
{ id: "song5" }
];
const pauseOthers = (songId: string) => {
const songsToStop = songs.filter(song => song.id !== songId);
console.log("songs to stop:", songsToStop.map(song => song.id).join(" "));
};
</script>
<!-- Audioplayer children component -->
<template>
<button block #click="emit('play', props.songId)">
something
</button>
</template>
<script lang="ts" setup>
const props = defineProps({
songId: {
type: String,
required: true
}
});
const emit = defineEmits(["play"]);
</script>
Note that all those props and emits are just created for being able to reproduce an example, you probably won't need them in your final code.
Related
I am trying to pass a value into a child component. The child component will then preform the save operation. The parent doesn't need to know anything about it. I am able to pass in the object but not save its updated form.
Parent
<template>
<div v-show="isOpened">
<EditModal #toggle="closeModal" #update:todo="submitUpdate($event)"
:updatedText="editText" :todo="modalPost" />
</div>
</template>
<script setup lang="ts">
import Post from "../components/Post.vue";
import { api } from "../lib/api";
import { ref } from "vue";
import { onMounted } from "vue-demi";
import EditModal from "../components/EditModal.vue";
const postArr = ref('');
const message = ref('');
let isOpened = ref(false);
let modalPost = ref('');
let editText = ref('');
function closeModal() {
isOpened.value = false
}
function openModal(value: string) {
isOpened.value = true
modalPost.value = value
}
// call posts so the table loads updated item
function submitUpdate(value: any) {
console.log("called update in parent " + value)
editText.value = value
posts()
}
</script>
Child EditModal
<template>
<div>
<div>
<textarea id="updateTextArea" rows="10" :value="props.todo.post"></textarea>
</div>
<!-- Modal footer -->
<div>
<button data-modal-toggle="defaultModal" type="button"
#click="update(props.todo.blogId, props.todo.post)">Save</button>
</div>
</div>
</template>
<script lang="ts" setup>
import { api } from "../lib/api";
import { reactive, ref } from "vue";
const props = defineProps({
todo: String,
updatedText: String,
})
const emit = defineEmits(
['toggle','update:todo']
);
function setIsOpened(value: boolean) {
emit('toggle', value);
}
function update(id: string, value: string) {
console.log('the value ' + value)
try {
api.updateBlog(id, value).then( res => {
emit('update:todo', value)
emit('toggle', false);
})
} catch (e) {
console.log('Error while updating post: '+ e)
}
}
</script>
I know the props are read only, therefore I tried to copy it I can only have one model.
I do not see the reason I should $emit to the parent and pass something to another variable to pass back to the child.
I am trying to pass in text to a modal component where it can edit the text and the child component saves it.
Advice?
First, your component should be named EditTodo no EditModal because you are not editing modal. All Edit components should rewrite props to new local variables like ref or reactive, so you can work on them, they won't be read only any more.
Child EditTodo.vue
<template>
<div>
<div>
<textarea id="updateTextArea" rows="10" v-model="data.todo.title"></textarea>
</div>
<div>
<button data-modal-toggle="defaultModal" type="button" #click="update()">Save</button>
</div>
</div>
</template>
<script setup lang="ts">
import { api } from "../lib/api";
import { reactive } from "vue";
const props = defineProps<{ id: number, todo: { title: string} }>()
const emit = defineEmits(['toggle']);
const data = reactive({ ...props })
// I assuming api.updateBlog will update data in database
// so job here should be done just need toogle false modal
// Your array with todos might be not updated but here is
// no place to do that. Well i dont know how your API works.
// Database i use will automaticly update arrays i updated objects
function update() {
try {
api.updateBlog(data.id, data.todo ).then(res => {
emit('toggle', false);
})
}
}
</script>
Parent
<template>
<div>
<BaseModal v-if="todo" :show="showModal">
<EditTodo :id="todo.id" :todo="todo.todo" #toggle="(value) => showModal = value"></EditTodo>
</BaseModal>
</div>
</template>
<script setup lang="ts">
const showModal = ref(false)
const todo = reactive({ id: 5, todo: { title: "Todo number 5"} })
</script>
I separated a modal object with edit form, so you can create more forms and use same modal. And here is a simple, not fully functional modal.
<template>
<div class="..."><slot></slot></div>
</template>
<script setup>
defineProps(['show'])
defineEmits(['toogle'])
</script>
You might want to close modal when user click somewhere outside of modal.
From my parent component, I need to trigger a child component's portion of code containing a Firebase query. Note that in the child component, that code is triggered within the mounted() hook (but in order to execute it from the parent component, I suppose I will have to move that code to a method or something).
What is the recommended way to achieve such a thing?
Here's my parent component code - simplified for clarity:
<template>
<div>
<nav>
<v-btn #click="viewNextWeek"></v-btn>
</nav>
<project-row :mon="mon"></new-row-form>
</div>
</template>
<script>
import ProjectRow from './ProjectRow.vue';
import store from '../store';
import moment from 'moment';
export default {
name: 'home',
components: {
ProjectRow
},
data() {
return {
mon: moment().startOf('isoWeek')
}
},
methods: {
viewNextWeek: function() {
this.mon = moment().startOf('isoWeek').add(7, 'days');
}
}
}
</script>
Child component - simplified too:
<template>
<div>
<input v-model="monTime">
</div>
</template>
<script>
import { db } from '../firebase';
export default {
props: [
'mon'
],
mounted() {
var timesRef = db.collection('times');
var timesWeek = timesRef.where('date', '==', this.mon);
timesWeek.get()
.then((querySnapshot) => {
querySnapshot.forEach((doc) => {
this.monTime = doc.data().time;
});
})
.catch(function(error) {
console.log('Error getting documents: ', error);
});
}
}
</script>
to achieve that you should use event bus communication between these two components. first, you should create a global event bus that can be a central event management and will give you the possibility to access any event from any component within your vuejs app. in your case here, you should emit an event from your parent component within viewNextWeek method and catch it within mounted in child component. so every time your mon value change within your parent component, will trigger an event to the child component to update mon within it.
for more detail for how to use global event bus, read this article global event bus article
(I'm new to vue and nuxt).
I currently have a <HeaderImage> component in my layouts/default.vue and would like to have each page to pass a different image url to that component.
Right now I'm using vuex $store for that purpose (but would love if there were a simpler way to pass the data), but I'm trying to figure out where in my pages/xyz.vue I should be using the mutation this.$store.commit('headerImg/setHeaderImage', 'someImage.jpg')
All of the examples I can find only use mutations on user events.
What you are trying to do probably doesn't have a particularly simple solution and how I would do it is use a store state element that is set by the component when it is loaded. The component would commit a mutation in the store that alters the state element. The layout would then use that state element through a getter to set the image url. Here is how I'd code that. In the store state i'd have an array of class names, let's call it 'headState', and an element that would be assigned one of those class names, called 'headStateSelect:
//store/index.js
state: {
headState: ['blue', 'red', 'green'],
headStateSelect : ''
}
In your component you can use fetch, or async fetch to commit a mutation that will set 'headStateSelect' with one of the 'headState' elements.
//yourComponent.vue
async fetch ({ store, params }) {
await store.commit('SET_HEAD', 1) //the second parameter is to specify the array position of the 'headState' class you want
}
and store:
//store/index.js
mutations: {
SET_HEAD (state, data) {
state.headStateSelect = state.headState[data]
}
}
In the store we should also have a getter that returns the 'headStateSelect' so our layout can easily get it.
getters: {
head(state) {
return state.headStateSelect
}
}
finally, in the layout we can use the computed property to get our getter:
//layouts/default.vue
computed: {
headElement() {
return this.$store.getters.head
}
}
and the layout can use the computed property to set a class like so:
//layouts/default.vue
<template>
<div :class="headElement">
</div>
</template>
The div in the layout will now be set with the class name 'red' (ie. store.state.headState[1]) and you can have a .red css class in your layout file that styles it however you want, including with a background image.
For now I've settled on creating it like this:
~/store/header.js
import Vue from 'vue'
import Vuex from 'vuex'
Vue.use(Vuex)
const state = () => ({
headerImage: 'default.jpg'
})
const mutations = {
newHeaderImage(state, newImage) {
state.headerImage = newImage
}
}
export default {
namespaced: true,
state,
mutations
}
``
~/layouts/default.vue
<template>
<div id="container">
<Header />
<nuxt />
</div>
</template>
<script>
import Header from '~/components/Header'
export default {
components: {
Header
}
}
</script>
``
~/components/Header.vue
<template>
<header :style="{ backgroundImage: 'url(' + headerImage + ')'}" class="fixed">
<h1>Header Text</h1>
</header>
</template>
<script>
computed: {
var image = this.$store.state.header.headerImage
return require('~/assets/img/' + image)
}
</script>
``
~/pages/customHeader.vue
<template>
<main>
...
</main>
</template>
<script>
export default {
head() {
this.$store.commit('header/newHeaderImage', 'custom-header.jpg')
return {
title: this.title
}
}
}
</script>
But something feels off about putting the mutation in head() Is that correct?
And the next issue I am facing is how to return the header to default.jpg if a page doesn't change the state (which makes me think this is all the wrong approach).
Let's say I have a main Vue instance that has child components. Is there a way of calling a method belonging to one of these components from outside the Vue instance entirely?
Here is an example:
var vm = new Vue({
el: '#app',
components: {
'my-component': {
template: '#my-template',
data: function() {
return {
count: 1,
};
},
methods: {
increaseCount: function() {
this.count++;
}
}
},
}
});
$('#external-button').click(function()
{
vm['my-component'].increaseCount(); // This doesn't work
});
<script src="http://vuejs.org/js/vue.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="app">
<my-component></my-component>
<br>
<button id="external-button">External Button</button>
</div>
<template id="my-template">
<div style="border: 1px solid; padding: 5px;">
<p>A counter: {{ count }}</p>
<button #click="increaseCount">Internal Button</button>
</div>
</template>
So when I click the internal button, the increaseCount() method is bound to its click event so it gets called. There is no way to bind the event to the external button, whose click event I am listening for with jQuery, so I'll need some other way to call increaseCount.
EDIT
It seems this works:
vm.$children[0].increaseCount();
However, this is not a good solution because I am referencing the component by its index in the children array, and with many components this is unlikely to stay constant and the code is less readable.
In the end I opted for using Vue's ref directive. This allows a component to be referenced from the parent for direct access.
E.g.
Have a component registered on my parent instance:
var vm = new Vue({
el: '#app',
components: { 'my-component': myComponent }
});
Render the component in template/html with a reference:
<my-component ref="foo"></my-component>
Now, elsewhere I can access the component externally
<script>
vm.$refs.foo.doSomething(); //assuming my component has a doSomething() method
</script>
See this fiddle for an example: https://jsfiddle.net/0zefx8o6/
(old example using Vue 1: https://jsfiddle.net/6v7y6msr/)
Edit for Vue3 - Composition API
The child-component has to return the function in setup you want to use in the parent-component otherwise the function is not available to the parent.
Note: <sript setup> doc is not affacted, because it provides all the functions and variables to the template by default.
You can set ref for child components then in parent can call via $refs:
Add ref to child component:
<my-component ref="childref"></my-component>
Add click event to parent:
<button id="external-button" #click="$refs.childref.increaseCount()">External Button</button>
var vm = new Vue({
el: '#app',
components: {
'my-component': {
template: '#my-template',
data: function() {
return {
count: 1,
};
},
methods: {
increaseCount: function() {
this.count++;
}
}
},
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<my-component ref="childref"></my-component>
<button id="external-button" #click="$refs.childref.increaseCount()">External Button</button>
</div>
<template id="my-template">
<div style="border: 1px solid; padding: 2px;" ref="childref">
<p>A counter: {{ count }}</p>
<button #click="increaseCount">Internal Button</button>
</div>
</template>
For Vue2 this applies:
var bus = new Vue()
// in component A's method
bus.$emit('id-selected', 1)
// in component B's created hook
bus.$on('id-selected', function (id) {
// ...
})
See here for the Vue docs.
And here is more detail on how to set up this event bus exactly.
If you'd like more info on when to use properties, events and/ or centralized state management see this article.
See below comment of Thomas regarding Vue 3.
You can use Vue event system
vm.$broadcast('event-name', args)
and
vm.$on('event-name', function())
Here is the fiddle:
http://jsfiddle.net/hfalucas/wc1gg5v4/59/
A slightly different (simpler) version of the accepted answer:
Have a component registered on the parent instance:
export default {
components: { 'my-component': myComponent }
}
Render the component in template/html with a reference:
<my-component ref="foo"></my-component>
Access the component method:
<script>
this.$refs.foo.doSomething();
</script>
Say you have a child_method() in the child component:
export default {
methods: {
child_method () {
console.log('I got clicked')
}
}
}
Now you want to execute the child_method from parent component:
<template>
<div>
<button #click="exec">Execute child component</button>
<child-cmp ref="child"></child_cmp> <!-- note the ref="child" here -->
</div>
</template>
export default {
methods: {
exec () { //accessing the child component instance through $refs
this.$refs.child.child_method() //execute the method belongs to the child component
}
}
}
If you want to execute a parent component method from child component:
this.$parent.name_of_method()
NOTE: It is not recommended to access the child and parent component like this.
Instead as best practice use Props & Events for parent-child communication.
If you want communication between components surely use vuex or event bus
Please read this very helpful article
This is a simple way to access a component's methods from other component
// This is external shared (reusable) component, so you can call its methods from other components
export default {
name: 'SharedBase',
methods: {
fetchLocalData: function(module, page){
// .....fetches some data
return { jsonData }
}
}
}
// This is your component where you can call SharedBased component's method(s)
import SharedBase from '[your path to component]';
var sections = [];
export default {
name: 'History',
created: function(){
this.sections = SharedBase.methods['fetchLocalData']('intro', 'history');
}
}
Using Vue 3:
const app = createApp({})
// register an options object
app.component('my-component', {
/* ... */
})
....
// retrieve a registered component
const MyComponent = app.component('my-component')
MyComponent.methods.greet();
https://v3.vuejs.org/api/application-api.html#component
Here is a simple one
this.$children[indexOfComponent].childsMethodName();
I am not sure is it the right way but this one works for me.
First import the component which contains the method you want to call in your component
import myComponent from './MyComponent'
and then call any method of MyCompenent
myComponent.methods.doSomething()
Declare your function in a component like this:
export default {
mounted () {
this.$root.$on('component1', () => {
// do your logic here :D
});
}
};
and call it from any page like this:
this.$root.$emit("component1");
If you're using Vue 3 with <script setup> sugar, note that internal bindings of a component are closed (not visible from outside the component) and you must use defineExpose(see docs) to make them visible from outside. Something like this:
<script setup lang="ts">
const method1 = () => { ... };
const method2 = () => { ... };
defineExpose({
method1,
method2,
});
</script>
Since
Components using are closed by default
Sometimes you want to keep these things contained within your component. Depending on DOM state (the elements you're listening on must exist in DOM when your Vue component is instantiated), you can listen to events on elements outside of your component from within your Vue component. Let's say there is an element outside of your component, and when the user clicks it, you want your component to respond.
In html you have:
Launch the component
...
<my-component></my-component>
In your Vue component:
methods() {
doSomething() {
// do something
}
},
created() {
document.getElementById('outsideLink').addEventListener('click', evt =>
{
this.doSomething();
});
}
I have used a very simple solution. I have included a HTML element, that calls the method, in my Vue Component that I select, using Vanilla JS, and I trigger click!
In the Vue Component, I have included something like the following:
<span data-id="btnReload" #click="fetchTaskList()"><i class="fa fa-refresh"></i></span>
That I use using Vanilla JS:
const btnReload = document.querySelector('[data-id="btnReload"]');
btnReload.click();
I am building a form framework in vue. I have components for each field type. Each field type component uses this.$emit to communicate changes with the parent component.
I am able to trigger events in the parent component using v-on directives as follows:
<template>
<div v-if="fieldsLoaded">
<form-select :field="fields.title" v-on:updated="validate" ></form-select>
<form-input :field="fields.first_name" v-on:updated="validate" ></form-input>
</div>
</template>
However, I don't want to have to manually specify that every component should trigger the validate method individually.
How can I have the parent component listen for the updated emit across all its child components?
Edit: I'm looking for something like the below, though $on only catches emits that occur within the same component, rather than its children
created: function(){
this.$on('updated',validate)
}
The best way is to use event bus or even better in my opinion vuex.
For the first case take a look here
For the second here
With event bus you can emit an event, and listen to that event whenever you want(at parent,child even in the same component)
Vuex It serves as a centralized store for all the components in an application and you can have properties in that store,and you can use and manipulate them.
Example with event Bus:
main.js:
import Vue from 'vue'
import App from './App.vue'
export const eventBus = new Vue();
new Vue({
el: '#app',
render: h => h(App)
})
User Component
<template>
<button #click="clicked">Click me to create event</button>
</template>
<script>
import { eventBus } from './main'
export default {
name: 'User',
methods: {
clicked() {
eventBus.$emit('customEvent', 'a text to pass')
}
}
}
</script>
Admin component
<template>
<p>The message from event is: {{message}}</p>
</template>
<script>
import { eventBus } from './main'
export default {
name: 'Admin',
data: () => ({
message: ''
})
created() {
eventBus.$on('customEvent', dataPassed => {
this.message = dataPassed
}
}
}
</script>
Take a look to this tutorial to learn Vuex
For your case you can use v-model like following:
<template>
<div v-if="fieldsLoaded">
<form-select v-model="fields.title" :validate="validate" ></form-select>
<form-input v-model="fields.first_name" :validate="validate" ></form-input>
</div>
</template>
v-model is essentially syntax sugar for updating data on user input events.
<input v-model="something">
is just syntactic sugar for:
<input v-bind:value="something" v-on:input="something = $event.target.value">
You can pass a prop : value in the child components, and before changing input field call a function to validate which is also passed as a prop.
Vue.component('form-select', {
props: ['options', 'value', 'onChange', 'validate'], //Added one more prop
template: '#your-template',
mounted: function () {
},
methods: {
change (opt) {
if (this.validate !== undefined) {
var isValid = this.validate(this.value)
if(!isValid) return;
}
this.$emit('input', opt)
},
},
})