How to access individual elements from a prop object in Vue - javascript

I am new to Vue and studied the other questions here and can not seem to work out how to pass an object to a child component and reference individual elements of that object. I want all elements of the object to be able to be individually accessed and used in the footer template where appropriate.
I am using NPM from node-js and run the dev with npm run dev
In my root component, App.Vue, I have as follows: (unrelated lines omitted)
<template>
<div>
<router-view></router-view>
<bbay-footer v-bind:footerData="footerData"></bbay-footer>
</div>
</template>
<script>
import Footer from './Components/SiteWide/Footer.vue'
export default {
components: {
'bbay-footer': Footer,
},
data() {
return {
footerData: [{
titleFooter: 'My Computer Support',
mainNumber: '0411111111',
otherNumber: '0400000000',
emailUs: 'mailto:info#mycomputersupport.com'
}]
}
}
}
</script>
Now in Footer.vue I have:
<template>
<footer>
<p>{{startCR}} - {{copyright}} </p>
</footer>
</template>
<script>
export default {
props: {
titleFooter: String,
mainNumber: Number,
otherNumber: Number,
emailUs: String
},
data () {
return {
copyright: "Copyright 2020: ",
startCR: this.footerData.titleFooter,
mNum: footerData.mainNumber,
oNum: footerData.otherNumber,
emailUs: footerData.emailUs
}
},
}
</script>

You are passing just 1 prop footerData but you have defined 4 in Footer.vue. Just define 1 prop in Footer.vue, and access as this.footerData[0].titleFooter, ...
export default {
props: {
footerData: Array,
},
data () {
return {
copyright: "Copyright 2020: ",
startCR: this.footerData[0].titleFooter,
mNum: this.footerData[0].mainNumber,
oNum: this.footerData[0].otherNumber,
emailUs: this.footerData[0].emailUs
}
},
}
You can handle the array in Footer.vue. You should define as many props as v-bind you are sending. https://v2.vuejs.org/v2/guide/components.html#Passing-Data-to-Child-Components-with-Props

Related

Vue2 use $ref to load data from child component and put into parent component's data

In Vue2 I'm trying to access child components' data and then put into parent component's data without triggering an event. In the following example I want to save count:20 into parent component, please tell me if there's any mistake, thanks!
Child Component
<template>
<div></div>
</template>
<script>
export default {
data() {
return {
count: 20,
};
},
};
</script>
Parent Component
<template>
<div>
<child ref="child1"></child>
{{count}}
</div>
</template>
<script> import child from './child.vue'
export default {
components: {
child
},
data() {
return{
count:this.$refs.child1.count
}
},
}
</script>
warn message in VScode
Property 'count' does not exist on type 'Vue | Element | Vue[] | Element[]'.
Property 'count' does not exist on type 'Vue'.
warn message in browser
[Vue warn]: Error in data(): "TypeError: undefined is not an object (evaluating 'this.$refs.child1')"
Let me preface with I would recommend using the Vue framework as intended. So passing data from a child to the parent should be done with $emit or using a vuex store for centralized state management.
With that out of the way you will want to wait until the parent component is mounted to set the count data attribute.
Child
<template>
<div></div>
</template>
<script>
export default {
data() {
return {
count: 20,
};
},
};
</script>
Parent
<template>
<div>
<child ref="child1"></child>
{{ count }}
</div>
</template>
<script>
import Child from "./components/Child";
export default {
components: {
Child
},
data() {
return{
count: 0
}
},
mounted () {
this.count = this.$refs.child1.count
}
};
</script>
This will work, however it WILL NOT BE reactive. This can all be greatly simplified AND made reactive with the following changes:
Child
<template>
<div></div>
</template>
<script>
export default {
data() {
return {
count: 20,
};
},
watch: {
count (currentValue) {
this.$emit('update', currentValue);
}
},
beforeMount () {
this.$emit('update', this.count)
}
};
</script>
Parent
<template>
<div>
<child #update="count = $event"></child>
{{ count }}
</div>
</template>
<script>
import Child from "./components/Child";
export default {
components: {
Child
},
data() {
return{
count: 0
}
}
};
</script>
Quick link to show a working example: https://codesandbox.io/s/interesting-kalam-et0b3?file=/src/App.vue

vuejs dynamic component throw error for v-bind:is, error is Property or method ... is not defined on the instance but referenced during render

Code in the file:
<template>
<component v-bind:is="bbc"></component>
</template>
<script>
import bbc from './bbc.vue';
export default {
name: 'ShowRoom2',
};
</script>
./bbc.vue
<script>
export default {
name: 'bbc',
props: {
msg: String,
},
mounted() {
console.log('bbc is mounted');
},
render() {
if (this.func) this.func();
return (
<div class="bbcMyClass">
<h1>bbc: <span>Pal</span> <span>{this.msg}</span></h1>
</div>
)
}
};
</script>
To reproduce
git clone git#github.com:adamchenwei/vue-hoc-playground.git
go to src/components/ShowRoom2.vue
yarn install && yarn serve
observe error in the local browser
Yes, the scope in the template is not the same as the script scope. If you need some data, you need to declare it inside the 'component' definition part of the code. For your case, I guess the 'data' property should work
import bbc from './bbc.vue';
export default {
name: 'ShowRoom2',
data() {
return {
bbc: bbc,
};
},
};
However, the template part of your code also looks weird. Could you explain what you're trying to do ?

Vue.js - Dynamic component import in data and computed properties

I have component 'Page' that should display a component which is retrieved via its props.
I managed to get my component loads when I harcode my component path in my component data like this :
<template>
<div>
<div v-if="includeHeader">
<header>
<fv-header/>
</header>
</div>
<component :is="this.componentDisplayed" />
<div v-if="includeFooter">
<footer>
<fv-complete-footer/>
</footer>
</div>
</div>
</template>
<script>
import Header from '#/components/Header/Header';
import CompleteFooter from '#/components/CompleteFooter/CompleteFooter';
export default {
name: 'Page',
props: {
componentPath: String,
includeHeader: Boolean,
includeFooter: Boolean
},
data() {
componentDisplayed: function () {
const path = '#/components/my_component';
return import(path);
},
},
components: {
'fv-header': Header,
'fv-complete-footer': CompleteFooter,
},
}
</script>
But with the data I cannot refer to my props within my function as this is undefined.
I tried to used computed properties instead of data but I have the error "src lazy?0309:5 Uncaught (in promise) Error: Cannot find module '#/components/my_component'. But the module exists! But maybe not at that time ?
computed: {
componentDisplayed: function () {
const path = `#/components/${this.componentPath}`;
return import(path);
},
},
There must be away to deal with that but I am quite a beginner to vue.js :)
Instead of trying to import the component in your child component, instead import it in the parent component and pass the entire component as a prop.
<template>
<div :is="component" />
</template>
<script>
export default {
name: "page",
props: {
component: {
required: true
}
}
};
</script>
And in the parent
<page :component="component" />
and
import Page from './components/Page';
// and further down
data () {
return {
component: HelloWorld
}
}

Change variable in component using vue.js

I have navbar blade, component with text and another components with page.
It works like I have component with text in navbar, and another component after navbar. That's three another components. How to change text from for example index.vue in text.vue?
That's what I have:
Text.vue:
<template>
<p class="title">{{msg}}</p>
</template>
<script>
export default {
props: [
'msg',
],
data() {
return {
}
},
mounted() {
},
methods: {
}
}
</script>
Component in navbar.blade.php:
<navbar-title></navbar-title>
And I try to change it in index.vue, that should work when we are on this page:
data() {
return {
msg: 'text',
}
But it doesn't work. How to do it correctly?
EDIT:
Vue.component('title', require('./components/Title.vue'));
To pass the message variable from your index.vue through navbar.vue to title.vue each needs to pass the property to the child and each child must pass the property on again all throughout the tree.
Something like this should work for your case: <title :msg="msg"></title>

Separating vuex stores for dynamically created components

This was the question got me stuck for a little bit. Unfortunately, I coudn't find answer here (asking also didn't help). So after doing some research and asking here and there, it seems that I got the solution to this issue.
If you have a question that you already know the answer to, and you
would like to document that knowledge in public so that others
(including yourself) can find it later.
Of course, my answer may not be the ideal one, moreover I know it is not, that's the key point why I'm posting - to improve it.
Note, I'm not using actions in example. The idea is the same.
Let's begin with stating the problem:
Imagine we have App.vue which dynamically generates its local component named Hello.
<template>
<div id="app">
<div>
<hello v-for="i in jobs" :key="i" :id="i"></hello>
<button #click="addJob">New</button>
</div>
</div>
</template>
<script>
import Hello from './components/Hello'
export default {
components: {
Hello
}...
store.js
export const store = new Vuex.Store({
state: {
jobs: []
}
})
We are using v-for directive to generate components by iterating through an array jobs. Our store as of now consists of only state with an empty array.
Button New should do 2 things:
1) create new component Hello, in other words add element to jobs (let it be numbers), which are going to be assigned as key and id of <hello>, and passed to local component as props.
2) generate local stores - modules - to keep any data scoped to newly created components.
Hello.vue
<template>
<div>
<input type="number" :value="count">
<button #click="updateCountPlus">+1</button>
</div>
</template>
export default {
props: ['id']
}
Simple component - input with a button adding 1.
Our goal is to design something like this:
For the first operation of NEW button - generating components - we add mutation to our store.js
mutations: {
addJob (state) {
state.jobs.push(state.jobs.length + 1)
...
}
Second, creating local modules. Here we're going to use reusableModule to generated multiple instances of a module. That module we keep in separate file for convinience. Also, note use of function for declaring module state.
const state = () => {
return {
count: 0
}
}
const getters = {
count: (state) => state.count
}
const mutations = {
updateCountPlus (state) {
state.count++
}
}
export default {
state,
getters,
mutations
}
To use reusableModule we import it and apply dynamic module registration.
store.js
import module from './reusableModule'
const {state: stateModule, getters, mutations} = module
export const store = new Vuex.Store({
state: {
jobs: []
},
mutations: {
addJob (state) {
state.jobs.push(state.jobs.length + 1)
store.registerModule(`module${state.jobs.length}`, {
state: stateModule,
getters,
mutations,
namespaced: true // making our module reusable
})
}
}
})
After, we're going to link Hello.vue with its storage. We may need state, getters, mutations, actions from vuex. To access storage we need to create our getters. Same with mutations.
Home.vue
<script>
export default {
props: ['id'],
computed: {
count () {
return this.$store.getters[`module${this.id}/count`]
}
},
methods: {
updateCountPlus () {
this.$store.commit(`module${this.id}/updateCountPlus`)
}
}
}
</script>
Imagine we have lots of getters, mutations and actions. Why not use {mapGetters} or {mapMutations}? When we have several modules and we know the path to module needed, we can do it. Unfortunately, we do not have access to module name.
The code is run when the component's module is executed (when your app
is booting), not when the component is created. So these helpers can
only be used if you know the module name ahead of time.
There is little help here. We can separate our getters and mutations and then import them as an object and keep it clean.
<script>
import computed from '../store/moduleGetters'
import methods from '../store/moduleMutations'
export default {
props: ['id'],
computed,
methods
}
</script>
Returning to App component. We have to commit our mutation and also let's create some getter for App. To show how can we access data located into modules.
store.js
export const store = new Vuex.Store({
state: {
jobs: []
},
getters: {
jobs: state => state.jobs,
sumAll (state, getters) {
let s = 0
for (let i = 1; i <= state.jobs.length; i++) {
s += getters[`module${i}/count`]
}
return s
}
}
...
Finishing code in App component
<script>
import Hello from './components/Hello'
import {mapMutations, mapGetters} from 'vuex'
export default {
components: {
Hello
},
computed: {
...mapGetters([
'jobs',
'sumAll'
])
},
methods: {
...mapMutations([
'addJob'
])
}
}
</script>
Hi and thank you for posting your question and your solution.
I started learning Vuex couple days ago and came across a similar problem. I've checked your solution and came up with mine which doesn't require registering new modules. I find it to be quite an overkill and to be honest I don't understand why you do it. There is always a possibility I've misunderstood the problem.
I've created a copy of your markup with a few differences for clarity and demonstration purposes.
I've got:
JobList.vue - main custom component
Job.vue - job-list child custom component
jobs.js - vuex store module file
JobList.vue (which is responsible for wrapping the job(s) list items)
<template>
<div>
<job v-for="(job, index) in jobs" :data="job" :key="job.id"></job>
<h3>Create New Job</h3>
<form #submit.prevent="addJob">
<input type="text" v-model="newJobName" required>
<button type="submit">Add Job</button>
</form>
</div>
</template>
<script>
import store from '../store/index'
import job from './job';
export default {
components: { job },
data() {
return {
newJobName: ''
};
},
computed: {
jobs() {
return store.state.jobs.jobs;
}
},
methods: {
addJob() {
store.dispatch('newJob', this.newJobName);
}
}
}
</script>
The Job
<template>
<div>
<h5>Id: {{ data.id }}</h5>
<h4>{{ data.name }}</h4>
<p>{{ data.active}}</p>
<button type="button" #click="toggleJobState">Toggle</button>
<hr>
</div>
</template>
<script>
import store from '../store/index'
export default {
props: ['data'],
methods: {
toggleJobState() {
store.dispatch('toggleJobState', this.data.id);
}
}
}
</script>
And finally the jobs.js Vuex module file:
export default {
state: {
jobs: [
{
id: 1,
name: 'light',
active: false
},
{
id: 2,
name: 'medium',
active: false
},
{
id: 3,
name: 'heavy',
active: false
}
]
},
actions: { //methods
newJob(context, jobName) {
context.state.jobs.push({
id: context.getters.newJobId,
name: jobName,
active: false
});
},
toggleJobState(context, id) {
context.state.jobs.forEach((job) => {
if(job.id === id) { job.active = !job.active; }
})
}
},
getters: { //computed properties
newJobId(state) { return state.jobs.length + 1; }
}
}
It's possible to add new jobs to the store and as the "active" property suggest, you can control every single individual job without the need for a new custom vuex module.

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