src/components/toast/README.md
Push notifications to your visitors with a
<b-toast>and<b-toaster>, lightweight components which are easily customizable for generating alert messages.
Toasts are lightweight notifications designed to mimic the push notifications that have been popularized by mobile and desktop operating systems.
Toasts are intended to be small interruptions to your visitors or users, and therefore should contain minimal, to-the-point, non-interactive content. Please refer to the Accessibility tips section below for important usage information.
To encourage extensible and predictable toasts, we recommend providing a header (title) and body.
Toast headers use the style 'display: flex', allowing easy alignment of content thanks to
Bootstrap's margin and flexbox utility classes.
Toasts are slightly translucent, too, so they blend over whatever they might appear over. For
browsers that support the backdrop-filter CSS property, they also attempt to blur the elements
under the toast.
<template>
<div class="p-3 bg-secondary progress-bar-striped" style="min-height: 170px;">
<b-button class="mb-2" variant="primary" @click="$bvToast.show('example-toast')">
Show toast
</b-button>
<b-toast id="example-toast" title="BootstrapVue" static no-auto-hide>
Hello, world! This is a toast message.
</b-toast>
</div>
</template>
<!-- toast-intro.vue -->
Note: we are using the static prop in the above example to render the toast in-place in the
document, rather than transporting it to a <b-toaster> target container. And we have added classes
bg-secondary and progress-bar-striped to the outer <div> for illustrative purposes of toast
transparency only.
this.$bvToast object, or manually created
using the <b-toast> component.<strong> element,
unless using the toast-title slot.no-close-button prop.no-close-button prop.auto-hide-delay prop, or disabled
with the no-auto-hide prop.no-hover-pause prop to true.solid prop to true.<b-toaster> target component. BootstrapVue comes with several
pre-defined toaster targets. Toasts will check for the named toaster in the document before they
are shown, and will dynamically create the named toaster target if one is not found.<b-toast> components.<div> with class b-toast to allow for Vue list-transition support when
displayed in a toaster component.BootstrapVue uses PortalVue to transport toasts into the toasters.
Generate a dynamic toast from anywhere in your app via the this.$bvToast Vue component instance
injection, without the need to place a <b-toast> component in your app.
Use the this.$bvToast.toast() method to generate on demand toasts. The method accepts two
arguments:
message: the content of the toast body (either a string, or an array of VNodes). Required.
Toasts with an empty message will not be shown. See the Advanced usage section
for an example of passing an array of VNodes as the message.options: an optional options object for providing a title and/or additional configuration
options. The title option can be either a string or an array of VNodesThe options argument accepts most of the props that the <b-toast> component accepts (with the
exception of static, and visible) in <samp>camelCase</samp> name format instead of
<samp>kebab-case</samp>.
<template>
<div>
<b-button @click="makeToast()">Show Toast</b-button>
<b-button @click="makeToast(true)">Show Toast (appended)</b-button>
</div>
</template>
<script>
export default {
data() {
return {
toastCount: 0
}
},
methods: {
makeToast(append = false) {
this.toastCount++
this.$bvToast.toast(`This is toast number ${this.toastCount}`, {
title: 'BootstrapVue Toast',
autoHideDelay: 5000,
appendToast: append
})
}
}
}
</script>
<!-- toasts-bv-toast-example.vue -->
Once a toast which was generated using this.$bvToast.toast() has been hidden, it will
automatically be destroyed and removed from the document.
Notes:
this.$bvToast injection is only available when using the full BootstrapVue plugin or the
ToastPlugin plugin. It is not available if importing just the b-toast or b-toaster
components. To just import the $bvToast injection, use the BVToastPlugin plugin.$bvToast injection (mixin) is created for each Vue virtual machine instance (i.e. each
instantiated component), and is not usable via direct access to the Vue.prototype, as it needs
access to the instance's this and $root contexts.this.$bvToast.toast() are children of the Vue instance that calls the
this.$bvToast.toast() method, and will be hidden and destroyed if that Vue instance (i.e. your
component or app) is also destroyed. If the vm context is inside a <router-view>, and the
$route changes, the toast will also be destroyed (as all the children of <router-view> are
destroyed. To make on-demand toasts persist across router $route changes, use
this.$root.$bvToast.toast() instead to make the toast's parent the root of your app.Toasts have various options that can control their style and behaviour. Options are available both
as props on the <b-toast> component and as properties of the options object passed to
this.$bvToast.toast(). When passing options to this.$bvToast.toast(), use the
<samp>camelCase</samp> version of the component prop name, i.e. use noAutoHide instead of
no-auto-hide.
Add a title to your toast via the title option. Just like the toast message, the title can be a
simple string, or an array of VNodes. See the Advanced usage section for an
example of passing an array of VNodes as the message and title.
Toasts have a semi-transparent background by default. To disable the default transparency, just set
the solid prop to true to remove the alpha channel from the background color.
Transparency can also be altered via the BootstrapVue custom SCSS variable
$b-toast-background-opacity when using the SCSS files rather than CSS files. Refer to the
Theming reference section.
BootstrapVue toasts provide custom CSS to define color variants. Variants follow the standard Bootstrap v4 variant names. If you have custom SCSS defined Bootstrap color theme variants, the toast custom SCSS will automatically create toast variants for you (refer to the Theming reference section).
<template>
<div>
<b-button @click="makeToast()" class="mb-2">Default</b-button>
<b-button variant="primary" @click="makeToast('primary')" class="mb-2">Primary</b-button>
<b-button variant="secondary" @click="makeToast('secondary')" class="mb-2">Secondary</b-button>
<b-button variant="danger" @click="makeToast('danger')" class="mb-2">Danger</b-button>
<b-button variant="warning" @click="makeToast('warning')" class="mb-2">Warning</b-button>
<b-button variant="success" @click="makeToast('success')" class="mb-2">Success</b-button>
<b-button variant="info" @click="makeToast('info')" class="mb-2">Info</b-button>
</div>
</template>
<script>
export default {
methods: {
makeToast(variant = null) {
this.$bvToast.toast('Toast body content', {
title: `Variant ${variant || 'default'}`,
variant: variant,
solid: true
})
}
}
}
</script>
<!-- toast-variants.vue -->
BootstrapVue comes with the following "built-in" toaster names (and associated styles defined in SCSS):
b-toaster-top-rightb-toaster-top-leftb-toaster-top-centerb-toaster-top-fullb-toaster-bottom-rightb-toaster-bottom-leftb-toaster-bottom-centerb-toaster-bottom-full<template>
<div>
<b-button @click="toast('b-toaster-top-right')" class="mb-2">b-toaster-top-right</b-button>
<b-button @click="toast('b-toaster-top-left')" class="mb-2">b-toaster-top-left</b-button>
<b-button @click="toast('b-toaster-top-center')" class="mb-2">b-toaster-top-center</b-button>
<b-button @click="toast('b-toaster-top-full')" class="mb-2">b-toaster-top-full</b-button>
<b-button @click="toast('b-toaster-bottom-right', true)" class="mb-2">b-toaster-bottom-right</b-button>
<b-button @click="toast('b-toaster-bottom-left', true)" class="mb-2">b-toaster-bottom-left</b-button>
<b-button @click="toast('b-toaster-bottom-center', true)" class="mb-2">b-toaster-bottom-center</b-button>
<b-button @click="toast('b-toaster-bottom-full', true)" class="mb-2">b-toaster-bottom-full</b-button>
</div>
</template>
<script>
export default {
data() {
return {
counter: 0
}
},
methods: {
toast(toaster, append = false) {
this.counter++
this.$bvToast.toast(`Toast ${this.counter} body content`, {
title: `Toaster ${toaster}`,
toaster: toaster,
solid: true,
appendToast: append
})
}
}
}
</script>
<!-- toast-targets.vue -->
Notes:
<body> inside a <b-toaster> with class name and ID set
to the toaster target name). The only default styling the toaster will have is a z-index of
1100.b-toaster-top-* toasters together, or b-toaster-bottom-* toasters together, at the
same time in your app as notifications could be obscured/overlap on small screens (i.e. xs).Toasts default to prepending themselves to the top of the toasts shown in the specified toaster in
the order they were created. To append new toasts to the bottom, set the append-toast prop to
true.
Change to auto hide delay time via the auto-hide-delay prop (value is in milliseconds), which
defaults to 5000 (minimum value 1000). Or, disable the auto-hide feature completely by setting
the no-auto-hide prop to true.
When auto-hide is enabled, hovering over the toast will pause the auto-hide timer. When you un-hover
the toast, the auto-hide timer will be resumed. You can disable this feature by setting the
no-hover-pause prop to true.
Toasts have a close button to hide them on use click by default. Setting the no-close-button prop
to true will prevent this and creates a toast without the default close button.
It is still possible to create a custom close button for the toast by providing a unique ID and use
the this.$bvToast.hide(id) method to hide the specific toast:
<template>
<div>
<b-button @click="showToast">Show Toast</b-button>
</div>
</template>
<script>
export default {
data() {
return {
count: 0
}
},
methods: {
showToast() {
// Use a shorter name for `this.$createElement`
const h = this.$createElement
// Create a ID with a incremented count
const id = `my-toast-${this.count++}`
// Create the custom close button
const $closeButton = h(
'b-button',
{
on: { click: () => this.$bvToast.hide(id) }
},
'Close'
)
// Create the toast
this.$bvToast.toast([$closeButton], {
id: id,
title: `Toast ${this.count}`,
noCloseButton: true
})
}
}
}
</script>
<!-- toasts-advanced.vue -->
Toasts are rendered with a default role attribute of 'alert' and aria-live attribute of
'assertive'. For toasts that are meant for a casual notification, set the is-status prop to
true, which will change the role and aria-live attributes to 'status' and 'polite'
respectively.
For more information, please the the Accessibility section below.
Optionally convert the toast body to a link (<a>) or <router-link> (or <nuxt-link>) via the
href and to props respectively. When set, the entire toast body becomes a link.
<template>
<div>
<b-button @click="toast()">Toast with link</b-button>
</div>
</template>
<script>
export default {
methods: {
toast() {
this.$bvToast.toast(`Toast with action link`, {
href: '#foo',
title: 'Example'
})
}
}
}
</script>
<!-- toast-link.vue -->
<b-toast> componentWhen you have a custom component that would like to display just a single toast at a time, use the
<b-toast> component. The <b-toast> component can be placed anywhere in your custom component or
app, and does not render an element (they render a comment placeholder node which will not affect
layout).
The toast can be made visible via a v-model (which is tied to the visible prop), or shown using
the component's show() and hide() instance methods, or via the this.$bvToast.show(id) and
this.$bvToast.hide(id) methods (requires that a unique ID be set on the <b-toast> component).
Toasts, by default will be paced into the b-toaster-top-right <b-toaster> component. The toaster
specified by the toaster prop will be created on demand if it doesn't already exist in document.
You can force a <b-toast> to appear in-place in the document by setting the static prop to
true. you still need to show and hide the toast, but it will not be transported into a toaster
component.
<template>
<div>
<b-button @click="$bvToast.show('my-toast')">Show toast</b-button>
<b-toast id="my-toast" variant="warning" solid>
<template #toast-title>
<div class="d-flex flex-grow-1 align-items-baseline">
<b-img blank blank-color="#ff5555" class="mr-2" width="12" height="12"></b-img>
<strong class="mr-auto">Notice!</strong>
<small class="text-muted mr-2">42 seconds ago</small>
</div>
</template>
This is the content of the toast.
It is short and to the point.
</b-toast>
</div>
</template>
<!-- toast-component.vue -->
toast-title: Content to replace the default title element.default: Content of the toast bodyBoth slots are optionally scoped with the following scope:
| Method or property | Description |
|---|---|
hide() | Hides the toast when called. Useful if you are providing your own close button. |
Slots are only available when using the <b-toast> component.
<b-toaster> target componentThe <b-toaster> component provides a container where toasts will appear (the Toaster). Toasters
require a unique name, and toasts can be targeted to appear in a specific named toaster.
In most cases you will not need to directly use this component, as <b-toast> will automatically
insert a <b-toaster> component (appended to <body>) with the requested toaster name if one is
not found in the document. But sometimes you may want to explicitly place a toaster in your app.
The toaster name becomes the ID of the inserted container, and will also be used a class name on
the rendered toaster container.
Toaster positioning and the positioning of toasts inside the toaster is driven completely by CSS classes (based on the name of the toaster)
The following "built-in" toaster names (and associated styles) are defined in BootstrapVue's custom SCSS:
b-toaster-top-rightb-toaster-top-leftb-toaster-top-centerb-toaster-top-fullb-toaster-bottom-rightb-toaster-bottom-leftb-toaster-bottom-centerb-toaster-bottom-fullThe above toasters place the toasts in a stacked (columnar format), fixed within the viewport (meaning they will always be in view regardless of viewport scroll position). If there are more toasts than can fit on the viewport screen, some will be visually hidden offscreen until other toasts are closed/hidden.
<b-toast> uses the b-toaster-top-right toaster by default.
Notes:
<b-toaster> with the same name already exists in document (either auto-created by
<b-toast>, this.$bvToast.toast(), or manually placed), then <b-toaster> will just render an
empty <div> element and issue a console warning.<b-toaster> component, make sure it is placed as the last element in
bottom of your app root element, so that it will be available to all pages in your app.<b-toaster>
component in your app, as they will be auto generated on demand if needed. But if you need to
override any of the toaster default settings, ensure that you place the toaster in your app in a
location that will not be destroyed due to changes in the route.When using the this.$bvToast.toast(...) method for generating toasts, you may want the toast
content to be more than just a string message. As mentioned in the
Toasts on demand section above, you can pass arrays of VNodes as the message
and title for more complex content.
Remember to keep toast content simple and to the point. Avoid placing interactive components or elements inside toasts, as this can cause issues for users of assistive technologies. Refer to the Accessibility section below.
Below is an example of using Vue's
this.$createElement() method
for generating more complex toast content:
<template>
<div>
<b-button @click="showToast">Show Toast with custom content</b-button>
</div>
</template>
<script>
export default {
data() {
return {
count: 0
}
},
methods: {
showToast() {
// Use a shorter name for this.$createElement
const h = this.$createElement
// Increment the toast count
this.count++
// Create the message
const vNodesMsg = h(
'p',
{ class: ['text-center', 'mb-0'] },
[
h('b-spinner', { props: { type: 'grow', small: true } }),
' Flashy ',
h('strong', 'toast'),
` message #${this.count} `,
h('b-spinner', { props: { type: 'grow', small: true } })
]
)
// Create the title
const vNodesTitle = h(
'div',
{ class: ['d-flex', 'flex-grow-1', 'align-items-baseline', 'mr-2'] },
[
h('strong', { class: 'mr-2' }, 'The Title'),
h('small', { class: 'ml-auto text-italics' }, '5 minutes ago')
]
)
// Pass the VNodes as an array for message and title
this.$bvToast.toast([vNodesMsg], {
title: [vNodesTitle],
solid: true,
variant: 'info'
})
}
}
}
</script>
<!-- toasts-advanced.vue -->
In some cases you may need just a simple alert style message (i.e. cookie usage notifications,
etc.). In these cases it is usually better to use an fixed position alert instead of a toast, by
applying a few Bootstrap utility classes and a small bit of
custom styling on a <b-alert> component:
<template>
<div>
<b-button size="sm" @click="showBottom = !showBottom">
{{ showBottom ? 'Hide' : 'Show' }} Fixed bottom Alert
</b-button>
<b-alert
v-model="showBottom"
class="position-fixed fixed-bottom m-0 rounded-0"
style="z-index: 2000;"
variant="warning"
dismissible
>
Fixed position (bottom) alert!
</b-alert>
<b-button size="sm" @click="showTop = !showTop">
{{ showTop ? 'Hide' : 'Show' }} Fixed top Alert
</b-button>
<b-alert
v-model="showTop"
class="position-fixed fixed-top m-0 rounded-0"
style="z-index: 2000;"
variant="success"
dismissible
>
Fixed position (top) alert!
</b-alert>
</div>
</template>
<script>
export default {
data() {
return {
showBottom: false,
showTop: false
}
}
}
</script>
<!-- fixed-position-alerts.vue -->
We use class position-fixed to set the positioning to fixed within the user's viewport, and either
class fixed-bottom or fixed-top to position the alert on the bottom or top of the viewport.
Class m-0 removes the default margins around the alert and rounded-0 removes the default rounded
corners. We also set the z-index to a large value to ensure the alert appears over any other
content on the page (the default for fixed-top and fixed-bottom is 1030). You may need to
adjust the z-index for your specific layout.
Since the alert markup remains in the DOM where you placed the <b-alert> component, its tab
sequence (for accessing the dismiss button) is easily accessible to screen reader and keyboard-only
users.
Toasts are intended to be small interruptions to your visitors or users, so to help those with
screen readers and similar assistive technologies, toasts are wrapped in an aria-live region.
Changes to live regions (such as injecting/updating a toast component) are automatically announced
by screen readers without needing to move the user's focus or otherwise interrupt the user.
Additionally, aria-atomic="true" is automatically set to ensure that the entire toast is always
announced as a single (atomic) unit, rather than announcing what was changed (which could lead to
problems if you only update part of the toast's content, or if displaying the same toast content at
a later point in time).
If you just need a single simple message to appear along the bottom or top of the user's window, use
a fixed position <b-alert> instead.
Typically, toast messages should display one or two-line non-critical messages that do not require user interaction. Without taking extra steps, toasts can have numerous accessibility issues that can impact both people with and without disabilities. The following list, while not complete, provides general guidelines when using toasts.
<b-alert> component instead of <b-toast>.<b-toast>, by default, sets the attributes role to 'alert' and aria-live to 'assertive'.
If it's an important message like an error, this default setting is appropriate, otherwise set the
prop is-status to true which will change the attributes role to 'status' and aria-live
to 'polite'.no-auto-hide to true, you must have a close button to allow users to dismiss
the toast. If you have also set prop no-close-button to true, you must provide your own close
button or dismiss the toast by some other means. Toasts have a tab index of 0 so that they can
be reached by keyboard-only users.auto-hide-delay to a larger timeout, to allow
users time to read the content of the toast. The average person reads about 200 words per minute,
so a good length of time to keep messages up is 5 seconds, plus 300 extra milliseconds per word.
The shortest default that should be used as a best practice is 5 seconds (5000ms). In addition to
a reasonable default timeout, you could also allow the user to choose how long they want toasts to
stay up for. Most people inherently understand whether they are fast or slow readers. Having a
profile setting that is part of the user login will allow slow readers to pick a longer time if
the messages are going away too fast, and fast readers to pick a short time if the messages are
staying up too long.Unfortunately, IE 11 when used with NVDA or
JAWS screen readers, will not properly
announce/voice toasts when they appear. If you have a large non-sighted user-base using IE 11, you
may want to create an additional off-screen aria-live region for IE 11 browsers only (created on
page load) where copies of toast message text are placed dynamically, in addition to displaying
toasts.