I made this using vue-cli. I have a component called InputField, and I render and mount the component to #app. I know that it will inject the component to the app, but how can I get the "default" value in index.html and access it in InputField.vue? I've tried to add props: "default" but the default value is undefined.
The idea is to get the default value from the component in html and save it to values in data when component is mounted.
I added the following ...
... to my html but seems like it wont work in vue-cli?
Also in my template I added default="def" like this:
<input default="def" v-model="values" name="my-input" />
But when I refer to "default" in js it is undefined.
InputField.vue
<template>
<div >
<input default="def" v-model="valuess" name="my-input" />
<input
v-model="message"
type="text">
<h2 class="message">{{ message }}</h2>
</div>
</template>
<script>
module.exports={
name:'InputField',
props:["default"],
mounted(){
console.log(this.default);
this.valuess=this.default;
},
updated(){
if(this.valuess===this.default){
return this.$emit('dirty-field',false);
}
this.$emit('dirty-field',true);
},
data: function () {
return {
valuess: '',
message:'heelo',
}
}
}
</script>
index.html
<div id="app">
<InputField default="My default text"></InputField>
</div>
main.js
new Vue({
render: h => h(InputField),
}).$mount('#app');
Try to pass default props like this with :default:
<InputField :default="My default text"></InputField>
Related
I have the following in App.vue
<template>
<div id="app">
<input type="text" v-model="term">
<hello-world text="Button 1" v-if="term === ''"></hello-world>
<hello-world v-else text="Button 2"></hello-world>
</div>
</template>
<script>
import HelloWorld from '#/components/HelloWorld'
export default {
name: 'app',
data() {
return {
term: ''
}
},
components: {
HelloWorld
}
}
</script>
And here's the HelloWorld.vue:
<template>
<div>
<button>{{ text }}</button>
</div>
</template>
<script>
export default {
props: {
text: String
},
created() {
console.log('Created')
},
destroyed() {
console.log('Destroyed')
}
}
</script>
So, when I type something the first component should be destroyed and the second component should be created. However, nothing like that happens. The component neither gets destroyed nor gets created.
It's as if the v-if didn't trigger the created() & destroyed() function. Please help me with this.
Vue uses virtual dom approach. So, it is comparing the virtual tree and it is not identifying changes on structure (oldNode.type === newNode.type). When it occurs, Vue updates the same component instead of destroying the old node and creating a new one.
Try to force Vue to detect virtual tree changes avoiding use siblings with the same tag name and controlled by v-if directive.
Reference:
https://medium.com/#deathmood/how-to-write-your-own-virtual-dom-ee74acc13060
Vue.component('hello-world', {
props: {
text: String
},
created() {
console.log('Created')
},
destroyed() {
console.log('Destroyed')
},
template: "<button>{{ text }}</button>"
});
var app = new Vue({
el: "#app",
data() {
return {
term: ''
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<input type="text" v-model="term">
<span><hello-world v-if="!term" text="Button 1"></hello-world></span>
<span><hello-world v-if="term" text="Button 2"></hello-world></span>
</div>
I am not sure what you are trying to achieve, but testing your code logs created from both components
https://codesandbox.io/s/8l0j43zy89
Since you are actually showing conditionally the same component, I don't think it will get destroyed.
I'm trying to wrap my head around hoe Vue.js works, reading lots of documents and tutorials and taking some pluralsight classes. I have a very basic website UI up and running. Here's the App.vue (which I'm using kinda as a master page).
(To make reading this easier and faster, look for this comment: This is the part you should pay attention to)...
<template>
<div id="app">
<div>
<div>
<CommandBar />
</div>
<div>
<Navigation />
</div>
</div>
<div id="lowerContent">
<!-- This is the part you should pay attention to -->
<template v-if="showLeftContent">
<div id="leftPane">
<div id="leftContent">
<router-view name="LeftSideBar"></router-view>
</div>
</div>
</template>
<!-- // This is the part you should pay attention to -->
<div id="mainPane">
<div id="mainContent">
<router-view name="MainContent"></router-view>
</div>
</div>
</div>
</div>
</template>
And then in the same App.vue file, here's the script portion
<script lang="ts">
import { Component, Vue } from 'vue-property-decorator';
import CommandBar from './components/CommandBar.vue';
import Navigation from './components/Navigation.vue';
#Component({
components: {
CommandBar,
Navigation,
}
})
export default class App extends Vue {
data() {
return {
showLeftContent: true // <--- This is the part you should pay attention to
}
}
}
</script>
Ok, so the idea is, one some pages I want to show a left sidebar, but on other pages I don't. That's why that div is wrapped in <template v-if="showLeftContent">.
Then with the named <router-view>'s I can control which components get loaded into them in the `router\index.ts\ file. The routes look like this:
{
path: '/home',
name: 'Home',
components: {
default: Home,
MainContent: Home, // load the Home compliment the main content
LeftSideBar: UserSearch // load the UserSearch component in the left side bar area
}
},
So far so good! But here's the kicker. Some pages won't have a left side bar, and on those pages, I want to change showLeftContent from true to false. That's the part I can't figure out.
Let's say we have a "Notes" component that looks like this.
<template>
<div class="notes">
Notes
</div>
</template>
<script lang="ts">
import { Component, Prop, Vue } from 'vue-property-decorator';
#Component
export default class Notes extends Vue {
data() {
return {
showLeftContent: false // DOES NOT WORK
}
}
}
</script>
Obviously, I'm not handling showLeftContent properly here. It would seem as if the properties in data are scoped only to that component, which I understand. I'm just not finding anything on how I can set a data property in the App component and then change it in a child component when that child is loaded through a router-view.
Thanks!
EDIT:
I changed the script section of the Notes component from:
<script lang="ts">
import { Component, Prop, Vue } from 'vue-property-decorator';
#Component
export default class Notes extends Vue {
data() {
return {
showLeftContent: false // DOES NOT WORK
}
}
}
</script>
to:
<script lang="ts">
import { Component, Prop, Vue } from 'vue-property-decorator';
#Component
export default class Notes extends Vue {
mounted() {
this.$root.$data.showLeftContent = false;
}
}
</script>
And while that didn't cause any compile or runtime errors, it also didn't have the desired effect. On Notes, the left side bar still shows.
EDIT 2:
If I put an alert in the script section of the Notes component:
export default class Notes extends Vue {
mounted() {
alert(this.$root.$data.showLeftContent);
//this.$root.$data.showLeftContent = false;
}
}
The alert does not pop until I click on "Notes" in the navigation. But, the value is "undefined".
EDIT 3:
Struggling with the syntax here (keep in mind this is TypeScript, which I don't know very well!!)
Edit 4:
Inching along!
export default class App extends Vue {
data() {
return {
showLeftContent: true
}
}
leftContent(value: boolean) {
alert('clicked');
this.$root.$emit('left-content', value);
}
}
This does not result in any errors, but it also doesn't work. The event never gets fired. I'm going to try putting it in the Navigation component and see if that works.
As it says on #lukebearden answer you can use the emit event to pass true/false to the main App component on router-link click.
Assuming your Navigation component looks like below, you can do something like that:
#Navigation.vue
<template>
<div>
<router-link to="/home" #click.native="leftContent(true)">Home</router-link> -
<router-link to="/notes" #click.native="leftContent(false)">Notes</router-link>
</div>
</template>
<script>
export default {
methods: {
leftContent(value) {
this.$emit('left-content', value)
}
}
}
</script>
And in your main App you listen the emit on Navigation:
<template>
<div id="app">
<div>
<Navigation #left-content="leftContent" />
</div>
<div id="lowerContent">
<template v-if="showLeftContent">
//...
</template>
<div id="mainPane">
//...
</div>
</div>
</div>
</template>
<script>
//...
data() {
return {
showLeftContent: true
}
},
methods: {
leftContent(value) {
this.showLeftContent = value
}
}
};
</script>
A basic approach in a parent-child component relationship is to emit events from the child and then listen and handle that event in the parent component.
However, I'm not sure that approach works when working with the router-view. This person solved it by watching the $route attribute for changes. https://forum.vuejs.org/t/emitting-events-from-vue-router/10136/6
You might also want to look into creating a simple event bus using a vue instance, or using vuex.
If you'd like to access the data property (or props, options etc) of the root instance, you can use this.$root.$data. (Check Vue Guide: Handling Edge)
For your codes, you can change this.$root.$data.showLeftContent to true/false in the hook=mounted of other Components, then when Vue creates instances for those components, it will show/hide the left side panel relevantly.
Below is one demo:
Vue.config.productionTip = false
Vue.component('child', {
template: `<div :style="{'background-color':color}" style="padding: 10px">
Reach to root: <button #click="changeRootData()">Click me!</button>
<hr>
<slot></slot>
</div>`,
props: ['color'],
methods: {
changeRootData() {
this.$root.$data.testValue += ' :) '
}
}
})
new Vue({
el: '#app',
data() {
return {
testValue: 'Puss In Boots'
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js"></script>
<div id="app">
<h2>{{testValue}}</h2>
<child color="red"><child color="gray"><child color="green"></child></child></child>
</div>
I have such code on different pages:
<div id="contact-us" class="section md-padding bg-grey">
<div id="contact"></div>
<script src="/dist/build.js"></script>
</div>
I have main.js:
import Vue from 'vue'
import Contact from './Contact.vue'
new Vue({
el: '#contact',
render: h => h(Contact)
})
And Contact.vue with a template
I want to know from which page component was used. So I need to pass param from div like <div id="contact" page="main"></div> . How can I implement this?
How to pass params from div to single page component in Vue.js?
You can't pass params from a div since it's a html tag and a not custom component, you should define your own component that accepts the properties you want to pass.
So first you should define your component and define the property is allow to receive, then you use your component, take a look to the below example, and you may find more information about passing props here.
Vue.component('your-component', {
props: ['property'],
template: '<h3>{{ property }}</h3>'
})
new Vue({
el: '#app'
})
<script src="https://cdn.jsdelivr.net/npm/vue#2.5.16/dist/vue.js"></script>
<div id="app">
<your-component :property="'Hello props'" />
</div>
Example using Single File Component structure.
Parent component:
<template>
<ChildComponent :property="propValue" />
</template>
<script>
import childComponent from './childComponent.vue';
export default {
components: {
ChildComponent: childComponent
},
data() {
return {
propValue: 'Hello prop'
}
}
}
</script>
Children component:
<template>
<h3>{{ property }}</h3>
</template>
<script>
export default {
props: ['property'] // You can add more properties separeted by commas
}
</script>
I've got a Vue file and I would like to set an 'action' attribute of my form.
<template>
<div>
<form>
</form>
</div>
</template>
export default {
created() {
var test = document.getElementById("form");
test.setAttribute('action', 'file.php');
}
But setting it in a lifecycle hook doesn't work. What should I do?
Couple of things:
The mounted lifecycle hook is usually where you want to perform the initial actions for the component
Using getElementById goes against the way Vue is supposed to be used
Something like this would make more sense:
<template>
<div>
<form :action='action'>
</form>
</div>
</template>
export default {
data() {
return {
action: 'file.php'
}
},
mounted() {
// initialize things here
}
}
In a Vue 2.0 app, let's say we have components A, B and C.
A declares, registers and uses B
Is it possible to pass C from A to B?
Something like this:
<template>
<div class="A">
<B :child_component="C" />
</div>
</template>
And use C in B somehow.
<template>
<div class="B">
<C>Something else</C>
</div>
</template>
The motivation: I want to create a generic component B that is used in A but receives from A its child C. Actually A will use B several times passing different 'C's to it.
If this approach is not correct, what is the proper way of doing it in Vue?
Answering #Saurabh
Instead of passing as props, I tried the suggestion inside B.
<!-- this is where I Call the dynamic component in B -->
<component :is="child_component"></component>
//this is what I did in B js
components: {
equip: Equipment
},
data () {
return {
child_component: 'equip',
_list: []
}
}
Basically I'm trying to render Equipment, but the dynamic way
I get 3 errors in console and a blank page
[Vue warn]: Error when rendering component at /home/victor/projetos/tokaai/public/src/components/EquipmentFormItem.vue:
Uncaught TypeError: Cannot read property 'name' of undefined
TypeError: Cannot read property 'setAttribute' of undefined
Apparently I'm doing something wrong
Summing up:
<!-- Component A -->
<template>
<div class="A">
<B>
<component :is="child_component"></component>
</B>
</div>
</template>
<script>
import B from './B.vue';
import Equipment from './Equipment.vue';
export default {
name: 'A',
components: { B, Equipment },
data() {
return { child_component: 'equipment' };
}
};
</script>
<!-- Component B -->
<template>
<div class="B">
<h1>Some content</h1>
<slot></slot> <!-- Component C will appear here -->
</div>
</template>
You can use special attribute is for doing this kind of thing. Example of dynamic component and its usage can be found here.
You can use the same mount point and dynamically switch between multiple components using the reserved element and dynamically bind to its is attribute.
Here's how is can be used with either an imported component or one passed as a prop:
<template>
<div class="B">
<component :is="myImportedComponent">Something</component>
--- or ---
<component :is="myPassedComponent">Something else</component>
</div>
</template>
<script>
import myImportedComponent from "#/components/SomeComponent.vue"
export default {
props: {
myPassedComponent: Object
},
components: {
myImportedComponent
},
}
</script>
Here's solution to forward custom component through props of another component
:is is special attribute and it will be used to replace your actual component and it will be ignored if you try to use it as a prop in your component. Luckily you can use something else like el and then forward this to component like so:
<template>
<div>
<component :is="el">
<slot />
</component>
</div>
</template>
<script>
export default {
name: 'RenderDynamicChild',
props: {
el: {
type: [String, Object],
default: 'div',
},
},
}
</script>
Any valid element you use in el attribute will be used as a child component. It can be html or reference to your custom component or div by default as specified in component declaration.
Passing custom component to prop is little bit tricky. One would assume you declare in a components property of parent component and then use it for el attribute but this doesn't work. Instead you need to have your dynamic component in data or computed property so you can use it in a template as a prop. Also note AnotherComponent doesn't need to be declared in components property.
<template>
<RenderDynamicChild :el="DynamicComponent">
Hello Vue!
</RenderDynamicChild>
</template>
<script>
import RenderDynamicChild from './DynamicChild';
import AnotherComponent from './AnotherComponent';
export default {
name: "ParentComponent",
components: { DynamicChild },
data() {
return {
DynamicComponent: AnotherComponent,
};
},
};
</script>
Using computed property for your dynamic component allows you to switch between components easily:
<script>
import DynamicChild from './DynamicChild';
import AnotherComponent from './AnotherComponent';
export default {
name: "ParentComponent",
components: { DynamicChild },
data() { return { count: 0 } },
computed: {
DynamicComponent() {
return this.count % 2 > 1 ? AnotherComponent : 'article';
},
},
};
</script>
Increase this.count to alternate between AnotherComponent and simple article html element.
Maybe it's too late to answer this question. But I think it could help others with this same issue.
I've been looking for a way to pass components throw others in vue, but it looks that VUE3 have a approach for that using named slots:
Here it's the documentation about that:
https://v3.vuejs.org/guide/component-slots.html#named-slots
Basically you can have:
<template>
<div class="A">
<slot name="ComponentC"></slot> <!-- Here will be rendered your ComponentC -->
</div>
<div class="A">
<slot name="ComponentD"></slot> <!-- Here will be rendered your ComponentD -->
</div>
<div class="A">
<slot></slot> <!-- This is going to be children components -->
</div>
</template>
And from your B component
<template>
<div class="B">
<A>
<template v-slot:ComponentC>
<h1>Title of ComponentC </h1>
</template>
<template v-slot:ComponentD>
<h1>Title of ComponentD </h1>
</template>
<template v-slot:default>
<h1>Title of child component </h1>
</template>
</A>
</div>
</template>
If you would like to use another component within your functional component you can do the following:
<script>
import Vue from 'vue'
import childComponent from './childComponent'
Vue.component('child-component')
export default {}
</script>
<template functional>
<div>
<child-component/>
</div>
</template>
Reference:
https://github.com/vuejs/vue/issues/7492#issue-290242300
If you mean Dynamically importing a component in a parent component, so yes, you can do that in Vue3 using:
<component :is="child_component" />
but to render "child_component" itself dynamically, you can use
import { defineAsyncComponent } from 'vue'
const AsyncComp = defineAsyncComponent(() =>
import('./components/MyComponent.vue')
)
Let me give you an example:
let's say you have several multiple child components (ChildA, ChildB, ChildC) that you want to load dynamically based on what you pass to the parent component (Parent), so the Parent component will be something like this:
Parent
<script setup lang="ts">
import { defineAsyncComponent } from 'vue';
const props = defineProps<{
childComponent?: string;
}>();
const AsyncComp = defineAsyncComponent(() =>
import(`./${props.childComponent}.vue`)
)
</script>
<template>
<component :is="AsyncComp"/>
</template>
and then you can call the Parent component dynamically wherever you want like this:
<Parent :childComponent="child-a"/>
<Parent :childComponent="child-b"/>
<Parent :childComponent="child-c"/>
For a better explanation, you can check this article:
https://medium.com/#pratikpatel_60309/dynamic-importing-component-templates-with-vue-js-78d2167db1e7