Reputation: 6622
I wrote a basic vue js 2 basic example to test nested components.
Below is components and template structure.
Vue.component('form-com', {
template: '#form',
props: ['value'],
methods: {
onInput: function (event) {
this.$emit('input', event.target.value);
}
}
});
Vue.component('message-com', {
template: '#message',
data: function () {
return {
msg: 'Hello'
}
},
props: ['user']
});
Vue.component('welcome-com', {
template: '#welcome',
data: function () {
return {
user: 'ahmad'
}
}
});
new Vue({
el: '#container'
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.js"></script>
<!--Form Template-->
<template id="form">
<div>
<div class="form-control">
<label>Enter Your Name:</label>
<input type="text" v-bind:value="value" :input="onInput">
</div>
</div>
</template>
<!--Hello Message Template-->
<template id="message">
<div>
<h3>{{msg}} {{user}}</h3>
</div>
</template>
<template id="welcome">
<div>
<form-com :value="value"></form-com>
<br>
<message-com :user="user"></message-com>
</div>
</template>
<div id="container">
<welcome-com></welcome-com>
</div>
But when run app in browser this error is shown:
[Vue warn]: Property or method "value" is not defined on the instance but referenced during render. Make sure to declare reactive data properties in the data option.
found in
---> <WelcomeCom>
<Root>
what is problem?
Update:
I just Rewrite this Fiddle from one of chapters of Learning Vue.js 2. I just rename some parameters and component and templates names. but when I copy main fiddle to my code all things worked.
Upvotes: 1
Views: 2847
Reputation: 31352
In your form-com component you can set up a v-model
which binds the input value and set up a watcher to observer the changes in the input which in turn emits an custom-event which tells the parent component that a change has taken place.
Vue.component('form-com', {
template: '#form',
data(){
return{
myInput:''
}
},
watch: {
myInput: function (inputVal) {
this.$emit('input', inputVal);
}
}
});
Vue.component('message-com', {
template: '#message',
data: function () {
return {
msg: 'Hello'
}
},
props: ['user']
});
Vue.component('welcome-com', {
template: '#welcome',
data: function () {
return {
user: 'ahmad'
}
},
methods:{
updateUser(value){
this.user = value;
}
}
});
new Vue({
el: '#container'
})
You can listen to the events emitted from the child **form-com ** component using v-on:input
or shorthand @input
directly in the parent template (welcome component) where the child component is used.
HTML
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.js"></script>
<!--Form Template-->
<template id="form">
<div>
<div class="form-control">
<label>Enter Your Name:</label>
<input type="text" v-model="myInput">
</div>
</div>
</template>
<!--Hello Message Template-->
<template id="message">
<div>
<h3>{{msg}} {{user}}</h3>
</div>
</template>
<template id="welcome">
<div>
<form-com @input="updateUser($event)" ></form-com>
<br>
<message-com :user="user"></message-com>
</div>
</template>
<div id="container">
<welcome-com></welcome-com>
</div>
Here is the jsFiddle
If you don't want to use a watcher then you can do it using computed setter . Have a look at the fiddle which is using a computed-setter
Upvotes: 2
Reputation: 1125
You are missing in your Component 'welcome-com' the value
object:
Vue.component('welcome-com', {
template: '#welcome',
data: function () {
return {
value: '',
user: 'ahmad'
}
}
});
Upvotes: 2