vue-form

Form validation for Vue.js 2.2+

Install

Available through npm as vue-form.

import VueForm from 'vue-form';

// install globally
Vue.use(VueForm);
Vue.use(VueForm, options);

// or use the mixin
...
mixins: [VueForm]
...
mixins: [new VueForm(options)]
...

Usage

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/

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,
  "$untouched": true,
  "$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,
    "$untouched": true,
    "$pending": false,
    "$error": {
      "required": true
    }
  },
  "email": {
    "$name": "email",
    "$dirty": false,
    "$pristine": true,
    "$valid": false,
    "$invalid": true,
    "$touched": false,
    "$untouched": true,
    "$pending": false,
    "$error": {
      "email": true
    }
  }
}

Displaying messages

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

<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>

Validators

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>

Custom validators

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 />
</validate>

Local custom validator

<validate :custom="{customValidator: customValidator}">
  <input v-model="something" name="something" />
</validate>

// ...
methods: {
	customValidator: function (value) {
		// return true to set input as $valid, false to set as $invalid
		return value === 'custom';
	}
}
// ...

Async validators:

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);
    });
  }
}

Reset state

<vue-form ref="form" :state="formstate">

resetState: function () {
  this.formstate._reset();
  // or
  this.$refs.form.reset();
}

State classes

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

Possible input classes:

vf-dirty, vf-pristine, vf-valid, vf-invalid

// 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

Custom components

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.

Component props

vue-form

state Object on which form state is set
tag String, defaults to form

validate

state Optional way of passing in the form state. If omitted form state will be found in the $parent
custom Object containing one or many custom validators. {validatorName: validatorFunction}
tag String which specifies what element tag should be rendered by the validate component, defaults to span
auto-label: Boolean, defaults to false. Automatically set for and id attributes of label and input elements found inside the validate component

field-messages

state Optional way of passing in the form state. If omitted form state will be found in the $parent
name String which specifies the related field name
tag String, defaults to div
show: String, show error dependant on form field state e.g. $touched, $dirty || $touched, '$touched || $submitted'
auto-label: Boolean, defaults to false. Automatically set the for attribute of labels found inside the field-messages component

field

tag String, defaults to div
auto-label: Boolean, defaults to true. Automatically set for and id attributes of label and input elements found inside the validate component

Config

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',
    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',
      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',
      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',
      submitted: 'vf-submitted',
      pending: 'vf-pending'
    },
    Promise: typeof Promise === 'function' ? Promise : null
}

JoelESvensson/vue-form

vue-form

Install

Usage

Displaying messages

Validators

Custom validators

Async validators:

Reset state

State classes

Custom components

Component props

vue-form

validate

field-messages

field

Config