I'm using VueJs and i have this children component in my father component, i need to trigger a function in the parent component, when the change in the select of the child component is detected.
Children component:
watch: {
selectCoin() {
this.$emit("currencyType", this.selectCoin["title"]);
}
}
Children component in my Father Component:
<app-select-coin
#coin="body.value = $event"
#currencyType="body.currencyType = $event"
:data="body"
/>
I need to call this method when the child component responds to $emit for the parent component:
methods :{
myFunction() {
}
}
I managed to do it by adding the function in the "v-on" in #currencyType, and passing as parameter the values i received from the children in "$emit".:
<app-select-coin
#coin="body.value = $event"
#currencyType="myFunction(body.currencyType = $event)"
:data="body"
/>
methods :{
myFunction(ct) {
}
}
Related
I have a parent component and a child.
From parent i want to call a method in child component and wait the response. How can i do that?
I need the response for adding a condition in the parent method.
<!-- MY CHILD COMPONENT -->
<my-child-component ref="childform" />
// parent method
methods: {
callChildMethod() {
this.$refs.childform.onSubmit()
// if want to get the response and do something
if (response) {
//do something
}
},
}
//child method
methods: {
onSubmit() {
//do something
return false
},
}
Your problem could be solved using refs and it works as follows:
In parent component:
<parent #click="clickHandler">
<child ref="child" />
</parent>
In your parent script tag:
methods: {
async clickHandler(){
//call child component's method using reference given in parent component
await this.$refs.child.child_method_name();
// rest of your parent code here
}
}
Here is my use case:
My main page have several sub-components that collect different input from user, finally I want to submit the whole page with all inputs collected. Therefore I want to retrieve the data from sub-component
One option is to use store, but my sub-components are super simple, just some forms, store seems too heavy...
Another option is that I can modify prop, although I know this is bad practice, but this approach looks just perfect....
Is it ok to modify prop if my logic is simple?(just collect inputs from user)Or I have to go for Vuex and store
Expanding on excellent answers from Ifaruki and Andres Foronda, another, related option is the use of the sync modifier on the child component's prop.
Suppose the child component has a prop named name. In the parent component, you can use the sync modifier like this:
<Child :name.sync="childName"></Child>
Then, in the child component, when the value of the name prop should be updated, don't update it directly. Instead, emit an event that follows the naming convention for sync-able props, which is update:nameOfProp. So in our example, the child component would do this:
this.$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>'
});
I have a child component called Card.vue where I make a card based on the length of an object in the parent component. In the child component I would like to use the data inside the object send from the parent. I get the error message that 'legend' is not defined. How do I do solve this?
Parent component:
<alst-card v-for="(legend, index) in profile.legends.all" :key="index" v-bind="legend"></alst-card>
Child component:
<p class="card-text" style="min-width: 100px">{{ legend.data.kills.value }}</p>
export default {
props: {
legend: Object
}
}
Try v-bind:legend="legend" instead of v-bind="legend"
The legend on the left is the props that the child component declared, the legend on the right is the data/property from the parent.
For example if your children declared:
export default {
props: {
givemelegend: Object
}
}
Then in Parent.Vue, you would want: v-bind:givemelegend="legend"
I have 3 vue.js nested components: main, parent, child.
The parent component load basic data, the child is a simple countdown widget which needs just a data to be configured.
If I set the parent script with static data (IE deadline='2019-12-12') the child show the widget working nice, but if I use dynamic data it generate error.
I'm using computed to pass data to the child component and if I debug it using an alert I see 2 alerts: undefined and then the correct date.
The issue is the first computed data (undefined) crash the widget, so how to create child component using updated (loaded) data?
Parent template:
<template>
<div>
<flip-countdown :deadline=deadline></flip-countdown>
</div>
</template>
Parent Script: it needs to be fixed
export default {
components: {FlipCountdown},
props: ['event'],
computed: {
deadline: function () {
if (typeof(this.event.date)!="undefined") {
//alert(this.event.date)
return this.event.date;
} else {
return "2019-05-21 00:00:00";
}
},
},
Child template: it works
<template>
<div>
<flip-countdown :deadline="deadline"></flip-countdown>
</div>
</template>
Your parent component passes the deadline to its child component before the mounted lifecycle hook fires. Your child component sets its deadline with the initial value of undefined.
You should make deadline a computed property in child component:
computed: {
internalDeadline() {
return this.deadline; // comming from props
}
}
Then you can use internalDeadline in child.
Alternatively, you could wait to render the child component until deadline is defined:
<flip-countdown v-if="deadline !== undefined" :deadline="deadline"></flip-countdown>