The Value of Variables does not update inside components - vue.js

When I put the input field inside a component, it doesn't update the value by any means. Is there something I've missed? Btw, I use Vue 3.
Child Component (input-form.vue)
<template>
<input
type="text"
:value="searchField"
#input="$emit('update:searchField', $event.target.value)"
/>
<p>Text Inside: {{ searchField }}</p>
</template>
<script>
export default {
emits: ["update:searchField"],
props: {
searchField: {
type: String,
},
},
};
</script>
Parent
<template>
<div>
<input-form :searchField="searchField" />
<p>Text Outside: {{ searchField }}</p>
</div>
</template>
<script>
import inputForm from "components/input-form.vue";
export default {
data() {
return {
searchField: "",
};
},
components: {
inputForm,
},
};
</script>

You are not listening for the update:searchField event in the Parent.
<input-form :searchField="searchField" #update:searchField="searchField = $event" />
or
<input-form v-model:searchField="searchField" />

Related

How to pass class attribute to child component element

how can I pass class attribute from parent to child component element?
Look here:
https://codesandbox.io/s/pedantic-shamir-1wuuv
I'm adding class to the Component "Input Field"
And my goal is that the 'custom-class' will be implemented on the 'input' element in the child component
But just still using the class attribute, and not setting a new prop like "customClass" and accept it in the props of the component
Thanks!
This depends on the template structure of your ChildComponent
Your Parent Component can look like this:
<div id="app">
<InputField class="anyClass" />
</div>
If your Child looks like this:
<template>
<input ... />
</template
Because if you have only 1 root Element in your template this will inherit the classes given automatically.
if your Template e.g. looks like this: (only available in vue3)
<template>
<input v-bind="$attrs" />
<span> hi </span>
</template
You will need the v-bind="$attrs" so Vue knows where to put the attributes to. Another Solution would be giving classes as props and assigning it to the element with :class="classes"
The pattern for the customs form component in Vue 2 where the props go to a child element looks something like this.
<template>
<div class="input-field">
<label v-if="label">{{ label }}</label>
<input
:value="value"
:class="inputClass"
#input="updateValue"
v-bind="$attrs"
v-on="listeners"
/>
</div>
</template>
<script>
export default {
inheritAttrs: false,
props: {
label: {
type: String,
default: "",
},
value: [String, Number],
inputClass: {
type: String,
default: "",
},
},
computed: {
listeners() {
return {
...this.$listeners,
input: this.updateValue,
};
},
},
methods: {
updateValue(event) {
this.$emit("input", event.target.value);
},
},
};
</script>
The usage of those components could look something like this.
```html
<template>
<div id="app">
<InputField
v-model="name"
label="What is your name?"
type="text"
class="custom"
inputClass="input-custom"
/>
<p>{{ name }}</p>
</div>
</template>
<script>
import InputField from "./components/InputField";
export default {
name: "App",
components: {
InputField,
},
data() {
return {
name: "",
};
},
};
</script>
A demo is available here
https://codesandbox.io/s/vue-2-custom-input-field-4vldv?file=/src/components/InputField.vue
You need to use vue props . Like this:
child component:
<template>
<div>
<input :class="className" type="text" value="Test" v-bind="$attrs" />
</div>
</template>
<script>
export default {
props:{
className:{
type:String,
default:'',
}
}
};
</script>
Parent component:
<div id="app">
<InputField :class-name="'custom-class'" />
</div>
Since you're using vue2 the v-bind=$attrs is being hooked to the root element of your component the <div> tag. Check the docs. You can put this wrapper on the parent element if you need it or just get rid of it.
Here is a working example
Another approach
There is also the idea of taking the classes from the parent and passing it to the child component with a ref after the component is mounted
Parent Element:
<template>
<div id="app">
<InputField class="custom-class" ref="inputField" />
</div>
</template>
<script>
import InputField from "./components/InputField";
export default {
name: "App",
components: {
InputField,
},
mounted() {
const inputField = this.$refs.inputField;
const classes = inputField.$el.getAttribute("class");
inputField.setClasses(classes);
},
};
</script>
Child Element:
<template>
<div>
<input type="text" value="Test" :class="classes" />
</div>
</template>
<script>
export default {
data() {
return {
classes: "",
};
},
methods: {
setClasses: function (classes) {
this.classes = classes;
},
},
};
</script>
Here a working example
In Vue2, the child's root element receives the classes.
If you need to pass them to a specific element of your child component, you can read those classes from the root and set them to a specific element.
Example of a vue child component:
<template>
<div ref="root">
<img ref="img" v-bind="$attrs" v-on="$listeners" :class="classes"/>
</div>
</template>
export default {
data() {
return {
classes: null,
}
},
mounted() {
this.classes = this.$refs.root.getAttribute("class")
this.$refs.root.removeAttribute("class")
},
}
Pretty much it.

Vuejs change component element value dynamicaly

I have a component in common between two other components A,B. This shared Comp has a button and its name changes depending on the component i use. How do I set the name dynamic?
I thought v-model solved the problem
What am I missing?
App.vue:
<test-a></test-a>
<test-b></test-b>
sharedComp.vue:
<template>
<div>
{{ btnValue }}
<input type="button" v-model="btnValue" />
</div>
</template>
<script>
export default {
data() {
return {
btnValue: "",
};
},
};
</script>
CompA.vue
<template>
<div>
<shared-comp
v-for="(item, index) in 3"
:key="index"
:value="'A'"
></shared-comp>
</div>
</template>
<script>
import SharedComp from "./SharedComp.vue";
export default {
components: { SharedComp },
};
</script>
CompB.vue
<template>
<div>
<shared-comp :value="'B'"></shared-comp>
</div>
</template>
<script>
import SharedComp from "./SharedComp.vue";
export default {
components: { SharedComp },
};
</script>
You have to define the properties you pass to your component inside of the 'sharedComp'.
Try something like:
<template>
<div>
{{ value }}
<input type="button" v-model="value" />
</div>
</template>
<script>
export default {
props: ['value'],
};
</script>
For further information on Props in Vue check the documentation page: https://v2.vuejs.org/v2/guide/components-props.html

How to change parent data from a child component?

After doing some digging, it seems that from child to parent you should update data by emitting events (not by v-model). This is my attempt of doing that (to no avail).
App.vue
<template>
<div>
<HelloWorld :count="count" #update:count="count= $event" />
</div>
</template>
<script>
import HelloWorld from "./components/HelloWorld.vue";
export default {
name: "App",
data() {
return {
count: 10
};
},
components: {
HelloWorld
}
};
</script>
HelloWorld.vue
<template>
<div class="hello">
<input
type="number"
min="0"
:value="count"
#input="$emit('input', $event.target.value)"
style="width:6em"
/>
</div>
</template>
<script>
export default {
name: "HelloWorld",
props: {
count: Number
}
};
</script>
Where am I going wrong? Ideally, I would like that changes in the input field of the child component would change the deposit field of the parent. Thanks!
I think that doesn't work because you're missing emits: ['update:count'] option in child component, But I recommend to name the prop as modelValue in child component and use v-model directive in parent instead of #update:count event :
<template>
<div>
<HelloWorld v-model="count" />
</div>
</template>
<script>
import HelloWorld from "./components/HelloWorld.vue";
export default {
name: "App",
data() {
return {
count: 10
};
},
components: {
HelloWorld
}
};
</script>
HelloWorld.vue :
<template>
<div class="hello">
<input
type="number"
min="0"
:value="count"
#input="$emit('update:modelValue', $event.target.value)"
style="width:6em"
/>
</div>
</template>
<script>
export default {
name: "HelloWorld",
props: {
modelValue: Number
},
emits: ['update:modelValue'],
};
</script>
This allows you to create a custom input

Vue: How do you bind a value to an input through a wrapper component?

I know you can use v-model to bind a value to an input in the same component. How do you create a wrapper component for an input and bind a value to it?
Login.vue
<template>
<div id="Login">
<Input v-bind:value="email"/>
<Input v-bind:value="password"/>
</div>
</template>
<script>
import Input from './Input.vue'
import Button from './Button'
export default {
name: 'Login',
components: {
Input,
Button,
},
data: () => ({
email:'test',
password:'test',
}),
methods: {
login: () => { debugger; }, //this.email and this.password are still set to test
}
}
</script>
Input.vue
<template>
<div class="input>
<input v-model="value"/>
</div>
</template>
<script>
export default {
name: 'Input',
props: {
value: String,
},
}
</script>
Current set up results in
[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. Prop being mutated: "value"
Is the only way to do this by emitting an event?
If I got it correctly, you can try to create transparent wrapper (in my case AppInput)
SomeParent.vue
<div>
<AppInput v-model="parentModel" />
</div>
AppInput.vue
<template>
<input
class="app-input"
v-bind="$attrs"
:value="value"
v-on="{
...$listeners,
input: event => $emit('input', event.target.value)
}">
</template>
<script>
export default {
name: "AppInput",
inheritAttrs: false,
props: ["value"]
};
</script>
one of articles
The best way is use v-model for wrapper and on/emit for input
<div id="Login">
<Input v-model="email"/>
<Input v-model="password"/>
</div>
...
<div class="input>
<input
v-bind:value="value"
v-on:input="$emit('input', $event.target.value)"
>
</div>
You can implement v-model directly in the input component by doing so.
<template>
<div class="input>
<input :value="value" #input="$emit('input', $event.target.value)"/>
</div>
</template>
<script>
export default {
name: 'Input',
props: ["value"]
}
</script>
And then use it in your parent component like this:
<template>
<div id="Login">
<Input v-model="email"/>
<Input v-model="password"/>
</div>
</template>
<script>
import Input from './Input.vue'
import Button from './Button'
export default {
name: 'Login',
components: {
Input,
Button,
},
data: () => ({
email:'test',
password:'test',
}),
methods: {
login: () => { debugger; }, //this.email and this.password are still set to test
}
}
</script>
See here

How to filter data from a parent component in a child component?

I have a component who show a list of data and I want to filter this list with different filters who are in a child component
I managed to do it with "computed" but only when I put everything in the parent component.
Test.vue
<template>
<div>
<filtres />
<garage v-for="g in garages" v-bind:gar="g" :key="g.id" />
</div>
</template>
<script>
export default {
name: 'test',
components: {
simplecomposant,
garage,
filtres
},
data(){
return{
garages: [],
}
},
mounted(){
var self = this;
axios.get('FETCHAPI').then(function (response)
{
self.garages = response.data.datas;
});
},
}
</script>
Filtres.vue
<template>
<div>
<label><input type="radio" v-model="selectedCity" value="All" /> All</label>
<label><input type="radio" v-model="selectedCity" value="1" /> City 1</label>
<label><input type="radio" v-model="selectedCity" value="2" />City 2</label>
</div>
</template>
<script>
export default {
name : 'filtres',
data(){
return{
selectedCity : "All"
}
},
}
</script>
garage.vue
<template>
<li class="aeris-simple-li">{{gar.name}}</span></li>
</template>
<script>
export default {
name : 'garage',
props: {
gar: {
type: Object
}
},
}
</script>
I want that when I select a filter (all, city 1, ...) it filters the datas "garages" who are in the parent component.