I am writing a dialog component, i don't know how to close dialog by self.
<template>
<div class="dialog" v-show="visible">
...
<button #click="close">Close</button>
</div>
</template>
<script>
{
props: {visible: {type: Boolean, default: false}},
methods: {
close () {
// this.visible = false //It will get vue warn
}
}
}
</script>
So, how to close the dialog in my component, i can't update visible prop, i will get a error.
Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or computed property based on the prop's value. Prop being mutated: "visible"
Props are one way data flow
You should not mutate the prop received from a parent component in the child component
So emit an custom event to mutate the prop in parent component itself
<template>
<div class="dialog" v-show="visible">
...
<button #click="close">Close</button>
</div>
</template>
<script>
{
props: {visible: {type: Boolean, default: false}},
methods: {
close () {
// this.visible = false //It will get vue warn
this.$emit('close-dialog')
}
}
}
</script>
parent component
<template>
<div>
<my-dialozg #close-dialog="visible = false" :visible="visible"><my-dialog>
</div>
</template>
Setup an event listener close-dialog on the dialog component and set the data property visible that you pass as a prop to false. You can do this inline as shown above or extract it into a method also
In vuejs, child component can not modify the parents property directly.
You can use events/event listeners for that. But since your example is simple you don't need an event for that.
Demo: https://jsfiddle.net/samayo/943bx5px/28/
Instead, you can pass the prop visible to your component as :visisble="visible" and watch the state change as:
watch: {
visible (val) {
if(!val) {
// close
}else{
open
}
}
}
Now, if visisble is toggled to false from the parent, your modal will not be visible.
Related
The use of v-model creates a two-way bind between the view and data model WITHIN a component. And a view interaction can emit an event to a parent component.
It is possible, though, to have a data model change in a child component emit an event to a parent component?
Because as long as the user is the one clicking the checkbox, things are fine in both the parent and the child (the data model updates AND the event is emitted). But if I pull up the Vue dev tools and toggle the checkbox within the child component's data, the two-way bind from the v-model will make the appropriate updates within the CHILD component, but nothing ever makes it over to the parent component (I suspect because an event is not emitted).
How can I make sure the parent component "knows" about the data change in the child component? I assume this must be possible in some way... If not emitting from the child, perhaps there's some way to have the parent component "watch" the child component's data?
Thank you for any help or guidance! I'll keep reading and looking for an answer in the meantime!
child component
<template>
<div class="list-item" v-on:click="doSomething">
<input type="checkbox" v-model="checked">
<label v-bind:class="{ checked: checked }">{{ name }}</label>
</div>
...
</template>
<script>
...
data: function() {
return {
checked: false,
}
},
methods: {
doSomething() {
...
this.$emit('doSomething', this)
}
}
</script>
parent component
<template>
<ChildComponent v-on:doSomething="getItDone"></ChildComponent>
...
</template>
<script>
...
methods: {
getItDone(target) {
...
}
}
</script>
UPDATE: After playing around a bit more with #IVO GELOV's solution, the issue I'm running into now is that, when multiple Child components are involved, since the Parent's one singular value of myBooleanVar drives the whole thing, checking the box of one child component causes all child components to be checked.
So it's definitely progress in that both view and data manipulations make it over to the parent, but I'm still trying to figure out how to "isolate" the situation so that just the one Child component that was acted upon gets dragged into the party...
You can keep the data in the parent, provide it to the child as a prop, make the child watch the prop and update its internal state, and finally emit an event to the parent when the internal state of the child has been changed.
parent
<template>
<ChildComponent v-model="myBooleanVar" />
...
</template>
<script>
data()
{
return {
myBooleanVar: false,
}
},
watch:
{
myBooleanVar(newValue, oldValue)
{
if (newValue !== oldValue) this.getItDone(newValue);
}
},
methods:
{
getItDone(value)
{
...
}
}
</script>
child
<template>
<div class="list-item">
<input type="checkbox" v-model="checked">
<label :class="{ checked: checked }">{{ name }}</label>
</div>
...
</template>
<script>
props:
{
value:
{
type: Boolean,
default: false
}
}
data()
{
return {
checked: this.value,
}
},
watch:
{
value(newVal, oldVal)
{
// this check is mandatory to prevent endless cycle
if(newVal !== oldVal) this.checked = newVal;
},
checked(newVal, oldVal)
{
// this check is mandatory to prevent endless cycle
if(newVal !== oldVal) this.$emit('input', newVal);
}
},
</script>
Maybe you can directly bind the checkbox attribut to the parent attribut using v-bind="$attrs"
Take a look at this answer: https://stackoverflow.com/a/56226236/10514369
Here is my use case:
My main page have several sub-components that collect different input from user, finally I want to submit the whole page with all inputs collected. Therefore I want to retrieve the data from sub-component
One option is to use store, but my sub-components are super simple, just some forms, store seems too heavy...
Another option is that I can modify prop, although I know this is bad practice, but this approach looks just perfect....
Is it ok to modify prop if my logic is simple?(just collect inputs from user)Or I have to go for Vuex and store
Expanding on excellent answers from Ifaruki and Andres Foronda, another, related option is the use of the sync modifier on the child component's prop.
Suppose the child component has a prop named name. In the parent component, you can use the sync modifier like this:
<Child :name.sync="childName"></Child>
Then, in the child component, when the value of the name prop should be updated, don't update it directly. Instead, emit an event that follows the naming convention for sync-able props, which is update:nameOfProp. So in our example, the child component would do this:
this.$emit('update:name', newName);
The benefit of the sync modifier is that we don't have to write an event handler function in the parent component--Vue does that for us and updates the variable that is bound to the prop automatically.
You can read more details about the sync modifier in the official docs.
Retreiving data from sub component works with $emit here an exapmle:
//parent copmonent
<template>
<div>
<child #someEvent="someMethod"></child>
</div>
</template>
import child from "path/"
<script>
export default {
components: {
child
},
methods: {
someMethod(data){
console.log(data);
}
}
}
</script>
Child component
<template>
<div>
<button #click="sendEvent">send</button>
</div>
</template>
<script>
export default {
methods: {
sendEvent(){
this.$emit("someEvent", "working");
}
}
}
</script>
$emit takes 2 arguments. The first is the event name and the second one is the data that you send.
The parent just needs to listen with # for that event that being fired.
you can listen an event from child an update the parent data property
//parent component
<div>
<input-name #updateName="eventToUpdateName" /> <!--child component-->
</div>
...
data: () => ({ nameFromChild: '' )},
methods: {
eventToUpdateName(value) {
this.nameFromChild = value; // Update from child value emitted
}
}
...
And in the child component
// Child component
<input v-model="name" />
...
data: () => ({ name: '' }),
// watch for changes in the name property and emit an event, and pass the value to the parent
watch: { name() { this.$emit('updateName', this.name } }
...
Also, You can use a v-model directive and emit 'input' event from child.
//parent component
<div>
<input-name v-model="nameFromChild" /> <!--child component-->
</div>
...
data: () => ({ nameFromChild: '' )}
...
Now in the child component you can have
// Child component
<div>
<input v-model="name" />
</div>
data: () => ({ name: '' }),
props: { value: { type: String, default: '' },
created() { this.name = this.value }, // You can receive a default value
watch: { name() { this.$emit('input', this.name } }
...
I have parent and chidl component... I need to run child method, when i click on button in parent.
Example code:
Parent
<template>
<child-component></child-component>
<button>Open Modal in child Component (set modal = true in child component)</button>
</template>
Child:
<template>
<div v-if="modal">
<button #click="modal = false">Close</button>
</div>
</template>
<script>
export default {
data() {
return {
modal: false
}
}
}
</script>
You can achieve this via different implementations. The most common one is via emit (another alternative is via dispatching actions if you are using the Redux pattern)
First, you want to catch the even on the parent component and emit an event. So this should be your template.
<template>
<child-component></child-component>
<button #click="click">Open Modal in child Component (set modal = true in child component)</button>
</template>
Then you have to emit an event (from the parent component) on the function called when a click was made.
Something like:
click: function() {
this.$emit('update');
}
Lastly, your child component needs to "hear" that event. You can achieve that with something like that on the created function of the child component:
this.$parent.$on('update', this.updateModal);
this.updateModal is a function on your child component which just flips the value of the boolean.
In vue you can pass a function as a prop. So you could add a function to alternate model within your parent component then pass it into your child so it can be used normally. I'll put a simple example below.
small edit, you can bind a class like a hidden/reveal class using the status which is bound to the modal state
// Html
<div id="app">
<child v-bind:on-click="toggleModal" v-bind:status="modal" />
</div>
// Parent Component
var sample = new Vue({
el: '#app',
data: {
modal: false
},
methods: {
toggleModal() {
this.modal = !this.modal
}
}
});
// Child component with function prop
Vue.component('child', {
props: {
onClick: Function,
status: Boolean
}
template: '<button v-on:click="onClick()">Press Me</div>'
});
Hi I made a boolean value in parent component, and passed it to the child component as a props. it has initialized as false, and after the user view the component, the value will change to true, which means the page has been visited.
I have done some research and followed How to properly pass data from child to parent and parent to child component?
here is my js code:
<script>
export default {
props: {
hasLoad: {
type: Boolean
}
},
data () {
return {
hasLoadModel: this.hasLoad
}
},
created: function() {
console.log(this.hasLoad);
},
beforeDestroy: function() {
this.hasLoadModel = true;
this.hasLoad = true;
console.log(this.hasLoadModel);
console.log(this.hasLoad);
}
}
</script>
and html code
<div v-model="skillLoadModel">..</div>
But I still get
[Vue warn]: Avoid mutating a prop directly since the value will be
overwritten whenever the parent component re-renders. Instead, use a
data or computed property based on the prop's value.
I have tried to change the value at either of beforeDestroy or Destroyed, or do not use v-model, but none of them works. The value has changed after I left the page, but when I reenter the page, the value has reset to default value.
Can someone help me please?
Thanks
Don't change the value of the prop. Have the component emit an event so that the parent can take the appropriate action.
Below is an example of a component that is created when the checkbox is checked, and is destroyed when it gets unchecked. The component emits a "dying" event, and the parent receives it and prints a scream to the console.
new Vue({
el: '#app',
data: {
showIt: true
},
methods: {
scream() {
console.log("Aaarg!");
}
},
components: {
myComponent: {
beforeDestroy: function() {
this.$emit('dying');
}
}
}
});
<script src="//unpkg.com/vue#latest/dist/vue.js"></script>
<div id="app">
<input type="checkbox" v-model="showIt">
<my-component v-if="showIt" hasload="true" #dying="scream" inline-template>
<div>Here I am</div>
</my-component>
</div>
I assume you're trying to communicate to the parent that the child has loaded. In that case, you can pass a function as a prop and simply call it when the child mounts.
Parent HTML:
<child :my-load-fn="loadFn"></child>
Parent JS:
methods: {
loadFn() {
this.childHasLoaded = true
}
}
Child JS:
props: ['myLoadFn'],
mounted() {
this.myLoadFn()
}
vuetify says: If you want to programmatically open or close the dialog, you can do so by using v-model with a boolean value.
However I am quite unclear on what this means. Saying "using v-model" is vague at best. The parent component knows on setup if it should open but I am unclear on how to dynamically change this in the child. Am i supposed to pass it using v-bind?
<login v-bind:showDialog></login>
If so how does the child component deal with this?
Vuetify Dialog info here: https://vuetifyjs.com/components/dialogs
As I understand you have a child component which have a dialog within it. Not sure that this is 100% right, but this is how I implement it. Child component with dialog:
<template>
<v-dialog v-model="intDialogVisible">
...
</template>
<script>
...
export default {
props: {
dialogVisible: Boolean,
...
},
computed: {
intDialogVisible: {
get: function () {
if (this.dialogVisible) {
// Some dialog initialization code could be placed here
// because it is called only when this.dialogVisible changes
}
return this.dialogVisible
},
set: function (value) {
if (!value) {
this.$emit('close', some_payload)
}
}
}
in parent component we use it:
<my-dilaog :dialogVisible="myDialogVisible"
#close="myDialogClose">
</my-dialog>
data () {
return {
myDialogVisible: false
}
},
methods: {
myDialogClose () {
this.myDialogVisible = false
// other code
}
}
Дмитрий Алферьев answer's is correct but get "Avoid mutating a prop directly" warning, because when close dialog, v-dialog try change v-model to false, while we passed props to v-model and props value won't change. to prevent the warning we should use :value , #input
<template>
<v-dialog :value="dialog" #input="$emit('update:dialog',false)" #keydown.esc="closeDialog()" >
...
</v-dialog>
</template>
<script>
export default {
props: {
dialog: Boolean
},
methods: {
closeDialog(){
this.$emit('closeDialog');
}
}
In parent
<template>
<v-btn color="primary" #click="showDialog=true"></v-btn>
<keep-alive>
<my-dialog
:dialog.sync="showEdit"
#closeDialog="closeDialog"
>
</my-dialog>
</keep-alive>
</template>
<script>
data(){
return {
showEdit:false,
},
},
methods: {
closeDialog(){
this.showEdit = false;
},
}
v-model is a directive. You would use v-model, not v-bind.
The page you link has several examples. If you click on the <> button on the first one, it shows HTML source of
<v-dialog v-model="dialog">
v-model makes a two-way binding on a prop that is named value inside the component. When you set the bound variable's value to true, the dialog will display; when false, it will hide. Also, if the dialog is dismissed, it will set the variable's value to false.