For cross browser consistency, <b-form-checkbox-group>
and <b-form-checkbox>
use
Bootstrap's custom checkbox input to replace the browser default checkbox input. It
is built on top of semantic and accessible markup, so it is a solid replacement for
the default checkbox input.
Example 1: Single checkbox
<template>
<div>
<b-form-checkbox id="checkbox1"
v-model="status"
value="accepted"
unchecked-value="not_accepted">
I accept the terms and use
</b-form-checkbox>
<div>State: <strong>{{status}}</strong></div>
</div>
</template>
<script>
export default {
data () {
return {
status: 'not_accepted'
}
}
}
</script>
Example 2: Multiple choice checkboxes
<template>
<div>
<b-form-group label="Using <code>options</code> array:">
<b-form-checkbox-group id="checkboxes1" name="flavour1" v-model="selected" :options="options">
</b-form-checkbox-group>
</b-form-group>
<b-form-group label="Using sub-components:">
<b-form-checkbox-group id="checkboxes2" name="flavour2" v-model="selected">
<b-form-checkbox value="orange">Orange</b-form-checkbox>
<b-form-checkbox value="apple">Apple</b-form-checkbox>
<b-form-checkbox value="pineapple">Pineapple</b-form-checkbox>
<b-form-checkbox value="grape">Grape</b-form-checkbox>
</b-form-checkbox-group>
</b-form-group>
<hr>
<div>Selected: <strong>{{ selected }}</strong></div>
</div>
</template>
<script>
export default {
data () {
return {
selected: [],
options: [
{text: 'Orange', value: 'orange'},
{text: 'Apple', value: 'apple'},
{text: 'Pineapple', value: 'pineapple'},
{text: 'Grape', value: 'grape'}
]
}
}
}
</script>
Feel free to mix and match options
prop and <b-form-checkbox>
in <b-form-checkbox-group>
.
Manually placed <b-form-checkbox>
inputs will appear below any checkbox inputs generated by
the options
prop. To have them apper above the inputs generated by options
, place them
in the named slot first
.
Options
Please see options in <b-form-select>
docs for details on passing
options (value array) to <b-form-checkboxes>
.
Inline and Stacked checkboxes
<b-form-checkbox>
components render as inline elements by default. Set the prop stacked
on
<b-form-checkbox-group>
to place each form control is on a separate line.
<template>
<div>
<b-form-group label="Inline checkboxes (default)">
<b-form-checkbox-group v-model="selected" name="flavour1" :options="options">
</b-form-checkbox-group>
</b-form-group>
<b-form-group label="Stacked checkboxes">
<b-form-checkbox-group stacked v-model="selected" name="flavour2" :options="options">
</b-form-checkbox-group>
</b-form-group>
</div>
</template>
<script>
export default {
data () {
return {
selected: [],
options: [
{text: 'Orange', value: 'orange'},
{text: 'Apple', value: 'apple'},
{text: 'Pineapple', value: 'pineapple'},
{text: 'Grape', value: 'grape'}
]
}
}
}
</script>
Value(s)
By default, <b-form-checkbox>
value will be true
when checked and false
when unchecked.
You can customize the checked and unchecked values by specifying the value
and unchecked-value
properties.
v-model
binds to the checked
property. When you have multiple checkboxes that bind to a
single data state variable, you must provide an array reference []
to your v-model
!
Note that when v-model
is bound to multiple checkboxes (i.e an array ref), the
unchecked-value
is not used. Only the value(s) of the checked chcekboxes will
be returned in the v-model
bound array. You should provide unique values for each
checkbox's value
prop.
Multiple checkboxes and accessibility
When binding multiple checkboxes together, you should set the name
prop to the same
value for all <b-formcheckbox>
s in the group individually or via the name
prop
of <b-form-checkbox-group>
. This will inform users of assitive technologies that the
checkboxes are related.
Whenever using multple checkboxes, it is recommended that the <b-form-check-group>
be placed in a <b-form-group>
component to
associate a label with the entire group of checkboxes.
Render checkboxes with the look of a button by setting the prop buttons
on <b-form-checkbox-group>
.
Change the button variant by setting the button-variant
prop to one of the standard Bootstrap
button variants (see <b-button>
for supported variants). The
default button-variant
is secondary
.
Button style checkboxes will have the class .active
automatically applied to the label
when they are in the checked state.
<template>
<div>
<b-form-group label="Button style checkboxes">
<b-form-checkbox-group buttons v-model="selected" name="butons1" :options="options">
</b-form-checkbox-group>
</b-form-group>
<b-form-group label="Button style checkboxes with variant <code>primary</code> and large buttons">
<b-form-checkbox-group v-model="selected"
buttons
button-variant="primary"
size="lg"
name="buttons2"
:options="options">
</b-form-checkbox-group>
</b-form-group>
<b-form-group label="Stacked (vertical) button style checkboxes">
<b-form-checkbox-group buttons v-model="selected" stacked :options="options">
</b-form-checkbox-group>
</b-form-group>
</div>
</template>
<script>
export default {
data () {
return {
selected: [],
options: [
{text: 'Orange', value: 'orange'},
{text: 'Apple', value: 'apple'},
{text: 'Pineapple', value: 'pineapple'},
{text: 'Grape', value: 'grape'}
]
}
}
}
</script>
Note: <b-form-checkbox-group>
uses the HTML attribute data-toggle="buttons"
to
apply the button styling to the checkboxes. This can cause a potential conflict if you
are including Bootstrap V4's jQuery code in your project for other purposes.
To get around this, you will need to exclude the Bootstrap V4 jQuery buttons plugin, and
include only the other Bootstrap V4 jQuery plugins you reqwuire.
You can have <b-form-checkbox-group>
or <b-form-checkbox>
render a browser native
chechbox input by setting the plain
prop.
<template>
<div>
<b-form-group label="Plain inline checkboxes">
<b-form-checkbox-group plain v-model="selected" :options="options" />
</b-form-group>
<b-form-group label="Plain stacked checkboxes">
<b-form-checkbox-group plain stacked v-model="selected" :options="options" />
</b-form-group>
</div>
</template>
<script>
export default {
data () {
return {
selected: [],
options: [
{text: 'Orange', value: 'orange'},
{text: 'Apple', value: 'apple'},
{text: 'Pineapple', value: 'pineapple'},
{text: 'Grape', value: 'grape'}
]
}
}
}
</script>
Note: The plain
prop has no effect when button
is set.
Contextual states
Bootstrap includes validation styles for valid
and invalid
states
on most form controls.
Generally speaking, you’ll want to use a particular state for specific types of feedback:
'invalid'
(or false
) is great for when there’s a blocking or required field. A user must fill in
this field properly to submit the form.
'valid'
(or true
) is ideal for situations when you have per-field validation throughout a form
and want to encourage a user through the rest of the fields.
null
Displays no validation state
To apply one of the contextual state icons on <b-form-checkbox>
, set the state
prop
to 'invalid'
(or false
), 'valid'
(or true
), or null
.
Note: Contextual states are not supported when in button mode.
Indeterminate (tri-state) support
Normally a checkbox input can only have two states: checked or unchecked. They can
have any value, but they either submit that value (checked) or don't (unchecked) with
a form submission (although Bootstrap-Vue allows a value for the unchecked state)
Visually, there are actually three states a checkbox can be in: checked,
unchecked, or indeterminate.
The indeterminate state is visual only. The checkbox is still either checked or
unchecked as a value. That means the visual indeterminate state masks the real value
of the checkbox, so that better make sense in your UI!
<b-form-checkbox>
supports setting this visual indeterminate state via the indeterminate
prop (defaults to false
). Clicking the checkbox will clear its indeterminate state.
The indeterminate
prop can be synced to the checkboxe's state by v-binding the
indeterminate
prop with the .sync
modifier.
Note: indeterminate is not supported in button mode, nor is it supported in
<b-form-checkbox-group>
(multiple checkboxes).
Single Indeterminate checkbox:
<template>
<div>
<b-form-checkbox v-model="checked" :indeterminate.sync="indeterminate">
Click me to see what happens
</b-form-checkbox>
<div class="mt-3">
Checked: <strong>{{ checked }}</strong><br>
Indeterminate: <strong>{{ indeterminate }}</strong>
</div>
<b-btn @click="toggleIndeterminate">Toggle Indeterminate State</b-btn>
</div>
</template>
<script>
export default {
data () {
return {
checked: true,
indeterminate: true
}
},
methods: {
toggleIndeterminate () {
this.indeterminate = !this.indeterminate
}
}
}
</script>
Indeterminate checkbox use-case:
<template>
<div>
<b-form-group>
<template slot="label">
<b>Choose your flavours:</b><br>
<b-form-checkbox v-model="allSelected"
:indeterminate="indeterminate"
aria-describedby="flavours"
aria-controls="flavours"
@change="toggleAll"
>
{{ allSelected ? 'Un-select All' : 'Select All' }}
</b-form-checkbox>
</template>
<b-form-checkbox-group id="flavors"
stacked
v-model="selected"
name="flavs"
:options="flavours"
class="ml-4"
aria-label="Individual flavours"
></b-form-checkbox-group>
</b-form-group>
<p>
Selected: <strong>{{ selected }}</strong><br>
All Selected: <strong>{{ allSelected }}</strong><br>
Indeterminate: <strong>{{ indeterminate }}</strong><br>
</p>
</div>
</template>
<script>
export default {
data () {
return {
flavours: ['Orange', 'Grape', 'Apple', 'Lime', 'Very Berry'],
selected: [],
allSelected: false,
indeterminate: false
}
},
methods: {
toggleAll (checked) {
this.selected = checked ? this.flavours.slice() : []
}
},
watch: {
selected (newVal, oldVal) {
if (newVal.length === 0) {
this.indeterminate = false
this.allSelected = false
} else if (newVal.length === this.flavours.length) {
this.indeterminate = false
this.allSelected = true
} else {
this.indeterminate = true
this.allSelected = false
}
}
}
}
</script>
Note: indeterminate is not supported in button
mode, nor in multiple checkbox mode.
Indeterminate state and accessibility
Not all screen readers will convey the indeterminate state to screen reader users.
So it is recommended to provide some form of textual feedback to the user (possibly
by via the .sr-only
class) if the indeterminate state has special contextual
meaning in your application.
Checkbox component aliases
<b-form-checkbox-group>
can be used by the shorter aliases <b-checkbox-group>
and <b-check-group>
.
<b-form-checkbox>
can be used by thes shorter aliases <b-checkbox>
and <b-check>
.
Component Reference