I have a button in my child component and when I click this button I want to add a class in my parent component. I added child component as a slot in parent component.
parent component:
<template>
<div :class="editMode ? 'class-add' : ''">
<slot name="default"></slot>
</div>
</template>
<script>
export default {
props: {
editMode: {
type: Boolean,
required: true,
},
},
};
</script>
child component:
<button #click="addClass">Click Me!!!</button>
addClass() {
this.$emit('edit-abc', true);
},
And here how I am adding the class:
<parent-component :edit-mode="editMode">
<template #default>
<child-component #edit-abc="editAbc($event)" />
</template>
</parent-component>
The problem is as you see, I have several abcs (abcs is an object which includes several abc) to send to child the class only the one which is clicked. So I believe here #edit-abc="editMode = $event", instead of editMode = $event, I need to create a function and filter the one that I want to add the class but my logic is wrong somewhere. Here what I have done as a function.
editAbc(event) {
this.abcs.filter((a) => {
if (a.id) {
this.$nextTick(() => {
return (this.editMode = event);
});
}
});
},
You have to declare the editMode data property to use it in your event handling.
data() {
return {
editMode: false
};
}
If you need to send separate events, then simply use different events.
You intentions with "several abcs" are not really clear. And it looks for me like you have a design flaw.
Please clarify it further.
UPDATE
Here is a stackblitz with the solution.
Related
I have a child component which includes form:
<el-form :model="abc" ref="ruleForm" :rules="rules">
<el-form-item prop="files">
<abc-card :title="getTranslation('abc.files')">
<file-selector v-model="abc.files" />
</abc-card>
</el-form-item>
</el-form>
And I want to add simple validations to this form:
rules: function () {
return {
files: [
{
type: 'object',
required: true,
trigger: 'change',
message: 'Field required',
},
],
};
},
But my click button is in the parent component:
<files v-model="editableAbc" ref="editableTab" />
<el-button type="primary" #click="submitForm()">Create</el-button>
methods: {
submitForm() {
this.$refs.form.validate((isValid) => {
if (!isValid) {
return;
}
////API CALLS////
});
},
}
So I am trying to achieve that when the button is clicked the navigation should be rendered. How can I do that?
As per your requirement, My suggestion would be to use a ref on child component to access its methods and then on submit click in parent component, trigger the child component method.
In parent component template :
<parent-component>
<child-component ref="childComponentRef" />
<button #click="submitFromParent">Submit</button>
</parent-component>
In parent component script :
methods: {
submitFromParent() {
this.$refs.childComponentRef.submitForm();
}
}
In child component script :
methods: {
submitForm() {
// Perform validations and do make API calls based on validation passed.
// If you want to pass success or failure in parent then you can do that by using $emit from here.
}
}
The "files" component is the form you're talking about?
If so, then ref should be placed exactly when calling the 'files' component, and not inside it. This will allow you to access the component in your parent element.
<files v-model="editableAbc" ref="ruleForm" />
There is a method with the props, which was mentioned in the comments above. I really don't like it, but I can tell you about it.
You need to set a value in the data of the parent component. Next you have to pass it as props to the child component. When you click the button, you must change the value of this key (for example +1). In the child component, you need to monitor the change in the props value via watch and call your validation function.
// Parent
<template>
<div class="test">
<ChildComponent />
</div>
</template>
<script>
export default {
data() {
return {
updateCount: 0,
};
},
methods: {
submitForm() {
// yout submit method
this.updateCount += 1;
},
},
};
</script>
// Child
<script>
export default {
props: {
updateCount: {
type: Number,
default: 0,
},
},
watch: {
updateCount: {
handler() {
this.validate();
},
},
},
methods: {
validate() {
// yout validation method
},
},
};
</script>
And one more solution. It is suitable if you cannot place the button in the child component, but you can pass it through the slot.
You need to pass the validate function in the child component through the prop inside the slot. In this case, in the parent component, you will be able to get this function through the v-slot and bind it to your button.
// Parent
<template>
<div class="test">
<ChildComponent>
<template #button="{ validate }">
<button #click="submitForm(validate)">My button</button>
</template>
</ChildComponent>
</div>
</template>
<script>
import ChildComponent from "./ChildComponent";
export default {
components: {
ChildComponent,
},
methods: {
submitForm(cb) {
const isValid = cb();
// your submit code
},
},
};
</script>
// Child
<template>
<div class="child-component">
<!-- your form -->
<slot name="button" :validate="validate" />
</div>
</template>
<script>
export default {
methods: {
validate() {
// yout validation method
console.log("validate");
},
},
};
</script>
I have this form on my parent:
<template>
<b-form #submit="onSubmit">
<CountryDropdown/>
</b-form>
</template>
<script>
import ...
export default {
form: {
country: ''
}
}
</script>
This is my Dropdown component using vue-select:
<template>
<v-select label="countryName" :options="countries" />
</template>
<script>
export default {
data() {
return {
countries: [
{ countryCode: 'EE', countryName: 'Estonia' },
{ countryCode: 'RU', countryName: 'Russia' }
]
}
}
}
</script>
I need to pass the countryCode value to its parent's form.country. I tried using $emit, but I cant seem to figure out how upon selection
it will set the parent value, and not upon submit.
EDIT:
The submitted solutions work great, I'll add my solution here:
I added an input event to my v-select:
<v-select #input="setSelected" ... />
in my script i define the selected and setSelected method :
data()
return
selected: ''
setSelected(value) {
this.selected = value.countryCode
this.$emit("selected", value.countryCode)
}
And in the parent:
<CountryDropdown v-on:selected="getCountry />
and parent script:
getCountry(country) {
this.form.country = country
}
You could use Vue's v-model mechanism to bind the output of vue-select to form.country in the container.
In CountryDropdown, implement v-model:
Add a prop named value 1️⃣, and bind it to vue-select.value 2️⃣
Emit input-event with the desired value. In this case, we want to emit countryCode as the value. 3️⃣
<template>
<v-select
:value="value" 2️⃣
#input="$emit('input', $event ? $event.countryCode : '')" 3️⃣
/>
</template>
<script>
export default {
props: ['value'], // 1️⃣
}
</script>
Now, the container of CountryDropdown could bind form.country to it, updating form.country to the selected country's countryCode upon selection:
<CountryDropdown v-model="form.country" />
demo
As you seem to know, $emit is what you need to use to send an event from a component to its' parent. To make that happen you need to add a few more things to your current code.
To get the options to list in your v-select you should use a computed function to isolate the names, like this:
computed: {
countryNames() {
return this.countries.map(c => c.countryName)
}
},
You will then need to list the names in your v-select like this:
<v-select label="countryName" :items="countryNames" #change="selectedCountry" />
You will see that #change is calling a method, this will be the method to emit your country code and it can do so like this:
methods: {
selectedCountry(e) {
let code = this.countries.find(cntry => cntry.countryName === e)
this.$emit('code', code.countryCode)
}
},
You will need a listener in your parent to hear the emit, so add something like this:
<CountryDropdown v-on:code="countryCodeFunction"/>
And then you just need a countryCodeFunction() in your methods that does something with the emitted code.
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.$emit('input', this.name } }
...
I have been reading lots of articles about this, and it seems that there are multiple ways to do this with many authors advising against some implementations.
To make this simple I have created a really simple version of what I would like to achieve.
I have a parent Vue, parent.vue. It has a button:
<template>
<div>
<button v-on:click="XXXXX call method in child XXXX">Say Hello</button>
</div>
</template>
In the child Vue, child.vue I have a method with a function:
methods: {
sayHello() {
alert('hello');
}
}
I would like to call the sayHello() function when I click the button in the parent.
I am looking for the best practice way to do this. Suggestions I have seen include Event Bus, and Child Component Refs and props, etc.
What would be the simplest way to just execute the function in my method?
Apologies, this does seem extremely simple, but I have really tried to do some research.
Thanks!
One easy way is to do this:
<!-- parent.vue -->
<template>
<button #click="$refs.myChild.sayHello()">Click me</button>
<child-component ref="myChild" />
</template>
Simply create a ref for the child component, and you will be able to call the methods, and access all the data it has.
You can create a ref and access the methods, but this is not recommended. You shouldn't rely on the internal structure of a component. The reason for this is that you'll tightly couple your components and one of the main reasons to create components is to loosely couple them.
You should rely on the contract (interface in some frameworks/languages) to achieve this. The contract in Vue relies on the fact that parents communicate with children via props and children communicate with parents via events.
There are also at least 2 other methods to communicate when you want to communicate between components that aren't parent/child:
the event bus
vuex
I'll describe now how to use a prop:
Define it on your child component
props: ['testProp'],
methods: {
sayHello() {
alert('hello');
}
}
Define a trigger data on the parent component
data () {
return {
trigger: 0
}
}
Use the prop on the parent component
<template>
<div>
<childComponent :testProp="trigger"/>
</div>
</template>
Watch testProp in the child component and call sayHello
watch: {
testProp: function(newVal, oldVal) {
this.sayHello()
}
}
Update trigger from the parent component. Make sure that you always change the value of trigger, otherwise the watch won't fire. One way of doing this is to increment trigger, or toggle it from a truthy value to a falsy one (this.trigger = !this.trigger)
I don't like the look of using props as triggers, but using ref also seems as an anti-pattern and is generally not recommended.
Another approach might be: You can use events to expose an interface of methods to call on the child component this way you get the best of both worlds while keeping your code somehow clean. Just emit them at the mounting stage and use them when pleased. I stored it in the $options part in the below code, but you can do as pleased.
Child component
<template>
<div>
<p>I was called {{ count }} times.</p>
</div>
</template>
<script>
export default {
mounted() {
// Emits on mount
this.emitInterface();
},
data() {
return {
count: 0
}
},
methods: {
addCount() {
this.count++;
},
notCallable() {
this.count--;
},
/**
* Emitting an interface with callable methods from outside
*/
emitInterface() {
this.$emit("interface", {
addCount: () => this.addCount()
});
}
}
}
</script>
Parent component
<template>
<div>
<button v-on:click="addCount">Add count to child</button>
<child-component #interface="getChildInterface"></child-component>
</div>
</template>
<script>
export default {
// Add a default
childInterface: {
addCount: () => {}
},
methods: {
// Setting the interface when emitted from child
getChildInterface(childInterface) {
this.$options.childInterface = childInterface;
},
// Add count through the interface
addCount() {
this.$options.childInterface.addCount();
}
}
}
</script>
With vue 3 composition api you can do it like this:
Parent.vue
<script setup lang="ts">
const childRef = ref()
const callSayHello = () => {
childRef.value.sayHello()
}
</script>
<template>
<child ref="childRef"></child>
</template>
<style scoped></style>
Child.vue
<script setup lang="ts">
const sayHello = () => {
console.log('Hello')
}
defineExpose({ sayHello })
</script>
<template></template>
<style scoped></style>
I am not sure is this the best way. But I can explain what I can do...
Codesandbox Demo : https://codesandbox.io/s/q4xn40935w
From parent component, send a prop data lets say msg. Have a button at parent whenever click the button toggle msg true/false
<template>
<div class="parent">
Button from Parent :
<button #click="msg = !msg">Say Hello</button><br/>
<child :msg="msg"/>
</div>
</template>
<script>
import child from "#/components/child";
export default {
name: "parent",
components: { child },
data: () => ({
msg: false
})
};
</script>
In child component watch prop data msg. Whenever msg changes trigger a method.
<template>
<div class="child">I am Child Component</div>
</template>
<script>
export default {
name: "child",
props: ["msg"],
watch: {
msg() {
this.sayHello();
}
},
methods: {
sayHello() {
alert("hello");
}
}
};
</script>
This is an alternate take on Jonas M's excellent answer. Return the interface with a promise, no need for events. You will need a Deferred class.
IMO Vue is deficient in making calling child methods difficult. Refs aren't always a good option - in my case I need to call a method in one of a thousand grandchildren.
Parent
<child :getInterface="getInterface" />
...
export default {
setup(props) {
init();
}
async function init() {
...
state.getInterface = new Deferred();
state.childInterface = await state.getInterface.promise;
state.childInterface.doThing();
}
}
Child
export default {
props: {
getInterface: Deferred,
},
setup(props) {
watch(() => props.getInterface, () => {
if(!props.getInterface) return;
props.getInterface.resolve({
doThing: () => {},
doThing2: () => {},
});
});
}
}
What is the correct way to wrap a component with another component while maintaining all the functionality of the child component.
my need is to wrap my component with a container, keeping all the functionality of the child and adding a trigger when clicking on the container outside the child that would trigger the child`s onclick event,
The parent component should emit all the child component events and accept all the props the child component accepts and pass them along, all the parent does is add a clickable wrapper.
in a way im asking how to extend a component in vue...
It is called a transparent wrapper.
That's how it is usually done:
<template>
<div class="custom-textarea">
<!-- Wrapped component: -->
<textarea
:value="value"
v-on="listeners"
:rows="rows"
v-bind="attrs"
>
</textarea>
</div>
</template>
<script>
export default {
props: ['value'], # any props you want
inheritAttrs: false,
computed: {
listeners() {
# input event has a special treatment in this example:
const { input, ...listeners } = this.$listeners;
return listeners;
},
rows() {
return this.$attrs.rows || 3;
},
attrs() {
# :rows property has a special treatment in this example:
const { rows, ...attrs } = this.$attrs;
return attrs;
},
},
methods: {
input(event) {
# You can handle any events here, not just input:
this.$emit('input', event.target.value);
},
}
}
</script>
Sources:
https://www.vuemastery.com/conferences/vueconf-us-2018/7-secret-patterns-vue-consultants-dont-want-you-to-know-chris-fritz/
https://zendev.com/2018/05/31/transparent-wrapper-components-in-vue.html