README.md
Form Checkbox
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="checkbox-1"
v-model="status"
name="checkbox-1"
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>
<!-- b-form-checkbox.vue -->
Example 2: Multiple choice checkboxes
<template>
<div>
<b-form-group label="Using options array:" v-slot="{ ariaDescribedby }">
<b-form-checkbox-group
id="checkbox-group-1"
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
name="flavour-1"
></b-form-checkbox-group>
</b-form-group>
<b-form-group label="Using sub-components:" v-slot="{ ariaDescribedby }">
<b-form-checkbox-group
id="checkbox-group-2"
v-model="selected"
:aria-describedby="ariaDescribedby"
name="flavour-2"
>
<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>
<div>Selected: <strong>{{ selected }}</strong></div>
</div>
</template>
<script>
export default {
data() {
return {
selected: [], // Must be an array reference!
options: [
{ text: 'Orange', value: 'orange' },
{ text: 'Apple', value: 'apple' },
{ text: 'Pineapple', value: 'pineapple' },
{ text: 'Grape', value: 'grape' }
]
}
}
}
</script>
<!-- b-form-checkbox-multiple.vue -->
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 appear above the inputs generated by options, place them in the
named slot first.
Checkbox group options array
options can be an array of strings or objects. Available fields:
valueThe selected value which will be set onv-modeldisabledDisables item for selectiontextDisplay text, orhtmlDisplay basic inline html
value can be a string, number, or simple object. Avoid using complex types in values.
If both html and text are provided, html will take precedence. Only basic/native HTML is
supported in the html field (components will not work). Note that not all browsers will render
inline html (i.e. <i>, <strong>, etc.) inside <option> elements of a <select>.
Be cautious of placing user supplied content in the html field, as it may make you vulnerable to XSS attacks, if you do not first sanitize the user supplied string.
<!-- eslint-disable no-unused-vars -->
const options = ['A', 'B', 'C', { text: 'D', value: { d: 1 }, disabled: true }, 'E', 'F']
If an array entry is a string, it will be used for both the generated value and text fields.
You can mix using strings and objects in the array.
Internally, BootstrapVue will convert the above array to the following array (the array of objects) format:
<!-- eslint-disable no-unused-vars -->
const options = [
{ text: 'A', value: 'A', disabled: false },
{ text: 'B', value: 'B', disabled: false },
{ text: 'C', value: 'C', disabled: false },
{ text: 'D', value: { d: 1 }, disabled: true },
{ text: 'E', value: 'E', disabled: false },
{ text: 'F', value: 'F', disabled: false }
]
Options as an array of objects
<!-- eslint-disable no-unused-vars -->
const options = [
{ text: 'Item 1', value: 'first' },
{ text: 'Item 2', value: 'second' },
{ html: '<b>Item</b> 3', value: 'third', disabled: true },
{ text: 'Item 4' },
{ text: 'Item 5', value: { foo: 'bar', baz: true } }
]
If value is missing, then text will be used as both the value and text fields. If you use
the html property, you must supply a value property.
Internally, BootstrapVue will convert the above array to the following array (the array of objects) format:
<!-- eslint-disable no-unused-vars -->
const options = [
{ text: 'Item 1', value: 'first', disabled: false },
{ text: 'Item 2', value: 'second', disabled: false },
{ html: '<b>Item</b> 3', value: 'third', disabled: true },
{ text: 'Item 4', value: 'Item 4', disabled: false },
{ text: 'Item 5', value: 'E', disabled: false }
]
Changing the option field names
If you want to customize the field property names (for example using name field for display
text) you can easily change them by setting the text-field, html-field, value-field, and
disabled-field props to a string that contains the property name you would like to use:
<template>
<div>
<b-form-checkbox-group
v-model="selected"
:options="options"
class="mb-3"
value-field="item"
text-field="name"
disabled-field="notEnabled"
></b-form-checkbox-group>
<div class="mt-3">Selected: <strong>{{ selected }}</strong></div>
</div>
</template>
<script>
export default {
data() {
return {
selected: [],
options: [
{ item: 'A', name: 'Option A' },
{ item: 'B', name: 'Option B' },
{ item: 'D', name: 'Option C', notEnabled: true },
{ item: { d: 1 }, name: 'Option D' }
]
}
}
}
</script>
<!-- b-form-checkbox-group-options-fields.vue -->
Inline and stacked checkboxes
<b-form-checkbox-group> components render inline checkboxes by default, while <b-form-checkbox>
renders block-level (stacked) checkboxes.
Set the prop stacked on <b-form-checkbox-group> to place each form control one over the other,
or if using individual checkboxes not inside a <b-form-checkbox-group>, set the inline prop on
<b-form-checkbox>.
<template>
<div>
<b-form-group
label="Form-checkbox-group inline checkboxes (default)"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
name="flavour-1a"
></b-form-checkbox-group>
</b-form-group>
<b-form-group
label="Form-checkbox-group stacked checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
name="flavour-2a"
stacked
></b-form-checkbox-group>
</b-form-group>
<b-form-group
label="Individual stacked checkboxes (default)"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox
v-for="option in options"
v-model="selected"
:key="option.value"
:value="option.value"
:aria-describedby="ariaDescribedby"
name="flavour-3a"
>
{{ option.text }}
</b-form-checkbox>
</b-form-group>
<b-form-group
label="Individual inline checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox
v-for="option in options"
v-model="selected"
:key="option.value"
:value="option.value"
:aria-describedby="ariaDescribedby"
name="flavour-4a"
inline
>
{{ option.text }}
</b-form-checkbox>
</b-form-group>
</div>
</template>
<script>
export default {
data() {
return {
selected: [], // Must be an array reference!
options: [
{ text: 'Orange', value: 'orange' },
{ text: 'Apple', value: 'apple' },
{ text: 'Pineapple', value: 'pineapple' },
{ text: 'Grape', value: 'grape' }
]
}
}
}
</script>
<!-- b-form-checkbox-stacked.vue -->
Control sizing
Use the size prop to control the size of the checkbox. The default size is medium. Supported size
values are sm (small) and lg (large).
<div>
<b-form-checkbox size="sm">Small</b-form-checkbox>
<b-form-checkbox>Default</b-form-checkbox>
<b-form-checkbox size="lg">Large</b-form-checkbox>
</div>
<!-- form-checkbox-sizes.vue -->
Sizes can be set on individual <b-form-checkbox> components, or inherited from the size setting of
<b-form-checkbox-group>.
Note: Bootstrap v4.x does not natively support sizes for the custom checkbox control. However, BootstrapVue includes custom SCSS/CSS that adds support for sizing the custom checkboxes.
Checkbox values and v-model
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, respectively.
The v-model binds to the checked prop. When you have multiple checkboxes that bind to a single
data state variable, you must provide an array reference ([]) to your v-model. Do not use
the checked prop directly.
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 checkboxes will be returned in the v-model bound
array. You should provide a unique value for each checkbox's value prop (the default of true
will not work when bound to an array)
To pre-check any radios, set the v-model to the value(s) of the checks that you would like
pre-selected.
When placing individual <b-form-checkbox> components within a <b-form-checkbox-group>, most
props and the v-model are inherited from the <b-form-checkbox-group>.
Note: the unchecked-value prop does not affect the native <input>'s value attribute,
because browsers don't include unchecked boxes in form submissions. To guarantee that one of two
values is submitted in a native <form> submit (e.g. 'yes' or 'no'), use radio inputs instead.
This is the same limitation that
Vue has with native checkbox inputs.
Multiple checkboxes and accessibility
When binding multiple checkboxes together, you must set the name prop to the same value for all
<b-form-checkbox>s in the group individually or via the name prop of <b-form-checkbox-group>.
This will inform users of assistive technologies that the checkboxes are related and enables native
browser keyboard navigation.
Whenever using multiple checkboxes, it is recommended that the checkboxes be placed in a <code><b-form-group></code> component to associate a label with the entire group of checkboxes. See examples above.
Button style checkboxes
You can optionally render checkboxes to appear as buttons, either individually, or in a group.
Button style checkboxes will have the class .active automatically applied to the label when they
are in the checked state.
Individual checkbox button style
A single checkbox can be rendered with a button appearance by setting the prop button to true
Change the button variant by setting the button-variant prop to one of the standard Bootstrap
button variants (see <code><b-button></code> for supported variants). The default
variant is secondary.
<template>
<div>
<b-form-checkbox v-model="checked1" name="check-button" button>
Button Checkbox <b>(Checked: {{ checked1 }})</b>
</b-form-checkbox>
<b-form-checkbox v-model="checked2" name="check-button" button button-variant="info">
Button Checkbox <b>(Checked: {{ checked2 }})</b>
</b-form-checkbox>
</div>
</template>
<script>
export default {
data() {
return {
checked1: false,
checked2: false
}
}
}
</script>
<!-- b-form-checkbox-button.vue -->
The inline prop has no effect on individual button-style checkboxes.
Grouped button style checkboxes
Render groups of checkboxes with the look of a button-group 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 <code><b-button></code> for supported
variants). The default button-variant is secondary.
<template>
<div>
<b-form-group
label="Button-group style checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
name="buttons-1"
buttons
></b-form-checkbox-group>
</b-form-group>
<b-form-group
label="Button-group style checkboxes with variant primary and large buttons"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
buttons
button-variant="primary"
size="lg"
name="buttons-2"
></b-form-checkbox-group>
</b-form-group>
<b-form-group
label="Stacked (vertical) button-group style checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
stacked
buttons
></b-form-checkbox-group>
</b-form-group>
</div>
</template>
<script>
export default {
data() {
return {
selected: [], // Must be an array reference!
options: [
{ text: 'Orange', value: 'orange' },
{ text: 'Apple', value: 'apple' },
{ text: 'Pineapple', value: 'pineapple' },
{ text: 'Grape', value: 'grape' }
]
}
}
}
</script>
<!-- b-form-checkbox-button-group.vue -->
Switch style checkboxes
Switch styling is supported on <b-form-checkbox> and <b-form-checkbox-group> components.
Note: If the checkbox is in button mode, switch mode will have no effect.
Individual checkbox switch style
A single checkbox can be rendered with a switch appearance by setting the prop switch to true
<template>
<div>
<b-form-checkbox v-model="checked" name="check-button" switch>
Switch Checkbox <b>(Checked: {{ checked }})</b>
</b-form-checkbox>
</div>
</template>
<script>
export default {
data() {
return {
checked: false
}
}
}
</script>
<!-- b-form-checkbox-switch.vue -->
Grouped switch style checkboxes
Render groups of checkboxes with the look of a switches by setting the prop switches on
<b-form-checkbox-group>.
<template>
<div>
<b-form-group
label="Inline switch style checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
switches
></b-form-checkbox-group>
</b-form-group>
<b-form-group
label="Stacked (vertical) switch style checkboxes"
v-slot="{ ariaDescribedby }"
>
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
switches
stacked
></b-form-checkbox-group>
</b-form-group>
</div>
</template>
<script>
export default {
data() {
return {
selected: [], // Must be an array reference!
options: [
{ text: 'Red', value: 'red' },
{ text: 'Green', value: 'green' },
{ text: 'Yellow (disabled)', value: 'yellow', disabled: true },
{ text: 'Blue', value: 'blue' }
]
}
}
}
</script>
<!-- b-form-checkboxes-switch-group.vue -->
Switch sizing
Use the size prop to control the size of the switch. The default size is medium. Supported size
values are sm (small) and lg (large).
<div>
<b-form-checkbox switch size="sm">Small</b-form-checkbox>
<b-form-checkbox switch>Default</b-form-checkbox>
<b-form-checkbox switch size="lg">Large</b-form-checkbox>
</div>
<!-- form-checkbox-switch-sizes.vue -->
Sizes can be set on individual <b-form-checkbox> components, or inherited from the size setting of
<b-form-checkbox-group>.
Note: Bootstrap v4.x does not natively support sizes for the custom switch control. However, BootstrapVue includes custom SCSS/CSS that adds support for sizing the custom switches.
Non custom check inputs (plain)
You can have <b-form-checkbox-group> or <b-form-checkbox> render a browser native checkbox input
by setting the plain prop.
<template>
<div>
<b-form-group label="Plain inline checkboxes" v-slot="{ ariaDescribedby }">
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
plain
></b-form-checkbox-group>
</b-form-group>
<b-form-group label="Plain stacked checkboxes" v-slot="{ ariaDescribedby }">
<b-form-checkbox-group
v-model="selected"
:options="options"
:aria-describedby="ariaDescribedby"
plain
stacked
></b-form-checkbox-group>
</b-form-group>
</div>
</template>
<script>
export default {
data() {
return {
selected: [], // Must be an array reference!
options: [
{ text: 'Orange', value: 'orange' },
{ text: 'Apple', value: 'apple' },
{ text: 'Pineapple', value: 'pineapple' },
{ text: 'Grape', value: 'grape' }
]
}
}
}
</script>
<!-- b-form-checkbox-plain.vue -->
Note: The plain prop has no effect when button or buttons 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:
false(denotes invalid state) is great for when there's a blocking or required field. A user must fill in this field properly to submit the form.true(denotes valid state) 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.nullDisplays no validation state (neither valid nor invalid)
To apply one of the contextual state icons on <b-form-checkbox>, set the state prop to false
(for invalid), true (for valid), or null (no validation state).
Note: Contextual states are not supported when in button mode.
Contextual state and validation example
<template>
<div>
<b-form-checkbox-group
v-model="value"
:options="options"
:state="state"
name="checkbox-validation"
>
<b-form-invalid-feedback :state="state">Please select two</b-form-invalid-feedback>
<b-form-valid-feedback :state="state">Thank you</b-form-valid-feedback>
</b-form-checkbox-group>
</div>
</template>
<script>
export default {
data() {
return {
value: [],
options: [
{ text: 'First Check', value: 'first' },
{ text: 'Second Check', value: 'second' },
{ text: 'Third Check', value: 'third' }
]
}
},
computed: {
state() {
return this.value.length === 2
}
}
}
</script>
<!-- form-checkbox-validation.vue -->
Required constraint
When using individual <b-form-checkbox> components (not in a <b-form-checkbox-group>), and you
want the checkbox(es) to be required in your form, you must provide a name on each
<b-form-checkbox> in order for the required constraint to work. All <b-form-checkbox> components
tied to the same v-model must have the same name.
The name is required in order for Assistive Technologies (such as screen readers, and keyboard
only users) to know which checkboxes belong to the same form variable (the name also automatically
enables native browser keyboard navigation), hence required will only work if name is set.
<b-form-checkbox-group> will automatically generate a unique input name if one is not provided on
the group.
Autofocus
When the autofocus prop is set on <b-form-checkbox>, the input will be auto-focused when it is
inserted (i.e. mounted) into the document, or re-activated when inside a Vue <keep-alive>
component. Note that this prop does not set the autofocus attribute on the input, nor can it
tell when the input becomes visible.
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 BootstrapVue allows a value for the unchecked state on a single checkbox)
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 checkbox's state by v-binding the indeterminate prop with the .sync
modifier.
Note: indeterminate styling is not supported in button or switch 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-button @click="toggleIndeterminate">Toggle Indeterminate State</b-button>
</div>
</template>
<script>
export default {
data() {
return {
checked: true,
indeterminate: true
}
},
methods: {
toggleIndeterminate() {
this.indeterminate = !this.indeterminate
}
}
}
</script>
<!-- b-form-checkbox-indeterminate.vue -->
Indeterminate checkbox use-case example:
<template>
<div>
<b-form-group>
<template #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>
<template v-slot="{ ariaDescribedby }">
<b-form-checkbox-group
id="flavors"
v-model="selected"
:options="flavours"
:aria-describedby="ariaDescribedby"
name="flavors"
class="ml-4"
aria-label="Individual flavours"
stacked
></b-form-checkbox-group>
</template>
</b-form-group>
<div>
Selected: <strong>{{ selected }}</strong><br>
All Selected: <strong>{{ allSelected }}</strong><br>
Indeterminate: <strong>{{ indeterminate }}</strong>
</div>
</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(newValue, oldValue) {
// Handle changes in individual flavour checkboxes
if (newValue.length === 0) {
this.indeterminate = false
this.allSelected = false
} else if (newValue.length === this.flavours.length) {
this.indeterminate = false
this.allSelected = true
} else {
this.indeterminate = true
this.allSelected = false
}
}
}
}
</script>
<!-- b-form-checkbox-indeterminate-multiple.vue -->
Note: indeterminate is not supported in button mode, nor in multiple checkbox mode. Also pay
attention that plain checkbox (i.e. with prop plain) also supports indeterminate state on
Windows/Linux/Mac/Android, but not on iOS.
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.
<!-- Component reference added automatically from component package.json -->