Form validation for Vue.js 2.2+
Available through npm as vue-form.
import VueForm from 'vue-form';
// or var VueForm = require('vue-form') or window.VueForm if you are linking directly to the dist file
// install globally
Vue.use(VueForm);
Vue.use(VueForm, options);
// or use the mixin
...
mixins: [VueForm]
...
mixins: [new VueForm(options)]
...Once installed you have access to four components (vue-form, validate, field, field-messages) for managing form state, validating form fields and displaying validation messages.
Live examples
- Configured to work with Bootstrap styles: https://jsfiddle.net/fergal_doyle/zfqt4yhq/
- Matching passwords and password strength: https://jsfiddle.net/fergal_doyle/9rn5kLkw/
- Field error messages based on submitted state (labels tied to inputs with
auto-label): https://jsfiddle.net/fergal_doyle/bqys2p5y/
Example
<div id="app">
<vue-form :state="formstate" @submit.prevent="onSubmit">
<validate tag="label">
<span>Name *</span>
<input v-model="model.name" required name="name" />
<field-messages name="name">
<div>Success!</div>
<div slot="required">Name is a required field</div>
</field-messages>
</validate>
<validate tag="label">
<span>Email</span>
<input v-model="model.email" name="email" type="email" required />
<field-messages name="email">
<div slot="required">Email is a required field</div>
<div slot="email">Email is not valid</div>
</field-messages>
</validate>
<button type="submit">Submit</button>
</vue-form>
<pre>{{ formstate }}</pre>
</div>Vue.use(VueForm);
new Vue({
el: '#app',
data: {
formstate: {},
model: {
name: '',
email: 'invalid-email'
}
},
methods: {
onSubmit: function () {
if(this.formstate.$invalid) {
// alert user and exit early
return;
}
// otherwise submit form
}
}
});The output of formstate will be:
{
"$dirty": false,
"$pristine": true,
"$valid": false,
"$invalid": true,
"$submitted": false,
"$touched": false,
"$untouched": true,
"$focused": false,
"$pending": false,
"$error": {
// fields with errors are copied into this object
},
"$submittedState": {
// each form sumbit, state is cloned into this object
},
"name": {
"$name": "name",
"$dirty": false,
"$pristine": true,
"$valid": false,
"$invalid": true,
"$touched": false,
"$untouched": true,
"$focused": false,
"$pending": false,
"$error": {
"required": true
}
},
"email": {
"$name": "email",
"$dirty": false,
"$pristine": true,
"$valid": false,
"$invalid": true,
"$touched": false,
"$untouched": true,
"$focused": false,
"$pending": false,
"$error": {
"email": true
}
}
}Display validation errors or success messages with field-messages.
The show prop supports simple expressions which specifiy when messages should be displayed based on the current state of the field, e.g: $dirty, $dirty && $touched, $dirty || $touched, $touched || $submitted, $focused && ($dirty || $submitted)
<field-messages name="name" show="$dirty && $touched">
<div slot="errorKeyA">Error message A</div>
<div slot="errorKeyB">Error message B</div>
</field-messages>Or use scoped templates:
<field-messages name="fieldName">
<span>Success</span>
<template slot="required" scope="state">
<span v-if="state.$touched || state.$submitted">Name is a required field</span>
</template>
<template slot="errorKeyB" scope="state">
<span v-if="state.$touched || state.$dirty">Error message B</span>
</template>
</field-messages>type="email"
type="url"
type="number"
required
minlength
maxlength
pattern
min (for type="number")
max (for type="number")
You can use static validation attributes or bindings. If it is a binding, the input will be re-validated every binding update meaning you can have inputs which are conditionally required etc.
<!-- static validators -->
<validate>
<input type="email" name="email" v-model="model.email" required />
</validate>
<validate>
<input type="text" name="name" v-model="model.name" maxlength="25" minlength="5" />
</validate>
<!-- bound validators -->
<validate>
<input type="email" name="email" v-model="model.email" :required="isRequired" />
</validate>
<validate>
<input type="text" name="name" v-model="model.name" :maxlength="maxLen" :minlength="minLen" />
</validate>You can register global and local custom validators.
Global custom validator
var options = {
validators: {
'my-custom-validator': function (value, attrValue, vnode) {
// return true to set input as $valid, false to set as $invalid
return value === 'custom';
}
}
}
Vue.use(VueForm, options);
// or
// mixins: [new VueForm(options)]<validate>
<input v-model="something" name="something" my-custom-validator />
<!--
slot name inside field-messages would be: <div slot="my-custom-validator">...</div>
-->
</validate>Local custom validator
// ...
methods: {
customValidator: function (value) {
// return true to set input as $valid, false to set as $invalid
return value === 'custom';
}
},
// local custom validator can also be a data or computed property
computed: {
isEmailAvailable: function () {
// return true to set input as $valid, false to set as $invalid
}
}
// ...<validate :custom="{customValidator: customValidator, 'email-available': isEmailAvailable}">
<input v-model="something" name="something" />
<!--
slot name inside field-messages would be: <div slot="customValidator">...</div>
-->
</validate>Async validators are custom validators which return a Promise. resolve() true or false to set field validity.
// ...
methods: {
customValidator (value) {
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve(value === 'ajax');
}, 100);
});
}
}
// ...Async validator with debounce (example uses lodash debounce)
methods: {
debounced: _.debounce(function (value, resolve, reject) {
fetch('https://httpbin.org/get').then(function(response){
resolve(response.isValid);
});
}, 500),
customValidator (value) {
return new Promise((resolve, reject) => {
this.debounced(value, resolve, reject);
});
}
}<vue-form ref="form" :state="formstate">
resetState: function () {
this.formstate._reset();
// or
this.$refs.form.reset();
}
As form and input validation states change, state classes are added and removed
Possible form classes:
vf-form-dirty, vf-form-pristine, vf-form-valid, vf-form-invalid, vf-form-submitted, vf-form-focused- vf-form-pending
Possible input classes:
vf-dirty, vf-pristine, vf-valid, vf-invalid, vf-focused, vf-pending
// also for every validation error, a class will be added, e.g.
vf-invalid-required, vf-invalid-minlength, vf-invalid-max, etc
Input wrappers (e.g. the tag the validate component renders) will also get state classes, but with the field prefix, e.g.
vf-field-dirty, vf-field-pristine, vf-field-valid, vf-field-invalid, vf-field-focused, vf-field-pending
When writing custom form field components, e.g. <my-checkbox v-model="foo"></my-checkbox> you should trigger the focus and blur events after user interaction either by triggering native dom events on the root node of your component, or emitting Vue events (this.$emit('focus)) so the validate component can detect and set the $dirty and $touched states on the field.
stateObject on which form state is settagString, defaults toformshow-messagesString, applies to all childfield-messages, show errors dependant on form field state e.g.$touched,$dirty || $touched, '$touched || $submitted'
stateOptional way of passing in the form state. If omitted form state will be found in the $parentcustomObject containing one or many custom validators.{validatorName: validatorFunction}tagString which specifies what element tag should be rendered by thevalidatecomponent, defaults tospanauto-label: Boolean, defaults to false. Automatically setforandidattributes of label and input elements found inside thevalidatecomponentdebounceNumber, defaults to none, which specifies the delay (milliseconds) before validation takes place.
stateOptional way of passing in the form state. If omitted form state will be found in the $parentnameString which specifies the related field nametagString, defaults todivshowString, show error dependant on form field state e.g.$touched,$dirty || $touched, '$touched || $submitted'auto-labelBoolean, defaults to false. Automatically set theforattribute of labels found inside thefield-messagescomponent
tagString, defaults todivauto-labelBoolean, defaults to true. Automatically setforandidattributes of label and input elements found inside thevalidatecomponent
Set config options when using Vue.use(VueForm, options), or when using a mixin mixins: [new VueForm(options)] defaults:
{
validators: {},
formComponent: 'vueForm',
formTag: 'form',
messagesComponent: 'fieldMessages',
messagesTag: 'div',
showMessages: '',
validateComponent: 'validate',
validateTag: 'div',
fieldComponent: 'field',
fieldTag: 'div',
formClasses: {
dirty: 'vf-form-dirty',
pristine: 'vf-form-pristine',
valid: 'vf-form-valid',
invalid: 'vf-form-invalid',
touched: 'vf-form-touched',
untouched: 'vf-form-untouched',
focused: 'vf-form-focused',
submitted: 'vf-form-submitted',
pending: 'vf-form-pending'
},
validateClasses: {
dirty: 'vf-field-dirty',
pristine: 'vf-field-pristine',
valid: 'vf-field-valid',
invalid: 'vf-field-invalid',
touched: 'vf-field-touched',
untouched: 'vf-field-untouched',
focused: 'vf-field-focused',
submitted: 'vf-field-submitted',
pending: 'vf-field-pending'
},
inputClasses: {
dirty: 'vf-dirty',
pristine: 'vf-pristine',
valid: 'vf-valid',
invalid: 'vf-invalid',
touched: 'vf-touched',
untouched: 'vf-untouched',
focused: 'vf-focused',
submitted: 'vf-submitted',
pending: 'vf-pending'
},
Promise: typeof Promise === 'function' ? Promise : null
}