Dialog
Dialogs inform users about a task and can contain critical information, require decisions, or involve multiple tasks.
Installation
Base UI components are all available as a single package.
npm install @base_ui/react
Once you have the package installed, import the component.
import { Dialog } from '@base_ui/react/Dialog';
Anatomy
Dialogs are implemented using a collection of related components:
<Dialog.Root />
is a top-level component that facilitates communication between other components. It does not render to the DOM.<Dialog.Popup />
is the dialog panel itself.<Dialog.Backdrop />
is the background element appearing when a popup is visible. Use it to indicate that the page is inert when using a modal dialog. The Backdrop must be a sibling of the Popup component. It is mandatory for modal dialogs.<Dialog.Trigger />
is the component (a button by default) that, when clicked, shows the popup. When it's not provided, the visibility of the Dialog can be controlled with itsopen
prop (see Controlled vs. uncontrolled behavior).<Dialog.Close />
renders a button that closes the popup. You can attach your own click handlers to it to perform additional actions.<Dialog.Title />
is an header element displaying the title of the dialog. It is referenced in the Dialog's ARIA attributes to properly announce the dialog.<Dialog.Description />
is an element describing of the dialog. It is referenced in the Dialog's ARIA attributes to properly announce the dialog.
<Dialog.Root>
<Dialog.Trigger />
<Dialog.Backdrop />
<Dialog.Popup>
<Dialog.Title />
<Dialog.Description />
<Dialog.Close />
</Dialog.Popup>
</Dialog.Root>
Modal and non-modal dialogs
Dialogs can be either modal (rendering the rest of the page inert) or non-modal. A non-modal dialog can be used to implement tool windows.
The modal
prop of the <Dialog.Root>
controls this.
By default Dialogs are modal.
<Dialog.Root modal={false}>{/* ... */}</Dialog.Root>
To make the Dialog fully modal, you must have a Backdrop component and style it so it covers the entire viewport, blocking pointer interaction with other elements on the page.
Closing the dialog
The default way to close the dialog is clicking on the <Dialog.Close>
component.
Dialogs also close when the user clicks outside of them or presses the Esc key.
Closing on outside click can be disabled with a dismissible
prop on the Dialog.Root
:
<Dialog.Root dismissible={false}>{/* ... */}</Dialog.Root>
Controlled vs. uncontrolled behavior
The simplest way to control the visibility of the dialog is to use the <Dialog.Trigger>
and <Dialog.Close>
components.
You can set the initial state with the defaultOpen
prop.
<Dialog.Root>
<Dialog.Trigger>Open</Dialog.Trigger>
<Dialog.Popup>
<Dialog.Title>Demo dialog</Dialog.Title>
<Dialog.Close>Close</Dialog.Close>
</Dialog.Popup>
</Dialog.Root>
Doing so ensures that the accessibity attributes are set correctly so that the trigger button is approriately announced by assistive technologies.
If you need to control the visibility programmatically from the outside, use the value
prop.
You can still use the <Dialog.Trigger>
and <Dialog.Close>
components (though it's not necessary), but you need to make sure to create a handler for the onOpenChange
event and update the state manually.
const [open, setOpen] = React.useState(false);
return (
<Dialog.Root open={open} onOpenChange={setOpen}>
<Dialog.Trigger>Open</Dialog.Trigger>
<Dialog.Popup>
<Dialog.Title>Demo dialog</Dialog.Title>
<Dialog.Close>Close</Dialog.Close>
</Dialog.Popup>
</Dialog.Root>
);
Nested dialogs
A dialog can open another dialog. At times, it may be useful to know how may open sub-dialogs a given dialog has. One example of this could be styling the bottom dialog in a way they appear below the top-most one.
The number of open child dialogs is present in the data-nested-dialogs
attribute and in the --nested-dialogs
CSS variable on the <Dialog.Popup>
component.
Note that when dialogs are nested, only the bottom-most backdrop is rendered.
Animation
The <Dialog.Popup>
and <Dialog.Backdrop>
components support transitions on entry and exit.
CSS animations and transitions are supported out of the box. If a component has a transition or animation applied to it when it closes, it will be unmounted only after the animation finishes.
As this detection of exit animations requires an extra render, you may opt out of it by setting the animated
prop on Root to false
.
We also recommend doing so in automated tests, to avoid asynchronous behavior and make testing easier.
Alternatively, you can use JavaScript-based animations with a library like framer-motion, React Spring, or similar.
With this approach set the keepMounted
to true
and let the animation library control mounting and unmounting.
CSS transitions
Here is an example of how to apply a symmetric scale and fade transition with the default conditionally-rendered behavior:
<Dialog.Popup className="DialogPopup">Dialog</Dialog.Popup>
.DialogPopup {
transition-property: opacity, transform;
transition-duration: 0.2s;
/* Represents the final styles once exited */
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
/* Represents the final styles once entered */
.DialogPopup[data-open] {
opacity: 1;
transform: translate(-50%, -50%) scale(1);
}
/* Represents the initial styles when entering */
.DialogPopup[data-entering] {
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
Styles need to be applied in three states:
- The exiting styles, placed on the base element class
- The open styles, placed on the base element class with
[data-open]
- The entering styles, placed on the base element class with
[data-entering]
In newer browsers, there is a feature called @starting-style
which allows transitions to occur on open for conditionally-mounted components:
/* Base UI API - Polyfill */
.DialogPopup[data-entering] {
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
/* Official Browser API - no Firefox support as of May 2024 */
@starting-style {
.DialogPopup[data-open] {
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
}
CSS animations
CSS animations can also be used, requiring only two separate declarations:
@keyframes scale-in {
from {
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
}
@keyframes scale-out {
to {
opacity: 0;
transform: translate(-50%, -35%) scale(0.8);
}
}
.DialogPopup {
animation: scale-in 0.2s forwards;
}
.DialogPopup[data-exiting] {
animation: scale-out 0.2s forwards;
}
JavaScript animations
The keepMounted
prop lets an external library control the mounting, for example framer-motion
's AnimatePresence
component.
function App() {
const [open, setOpen] = useState(false);
return (
<Dialog.Root open={open} onOpenChange={setOpen}>
<Dialog.Trigger>Trigger</Dialog.Trigger>
<AnimatePresence>
{open && (
<Dialog.Popup
keepMounted
render={
<motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }} />
}
>
Dialog
</Dialog.Popup>
)}
</AnimatePresence>
</Dialog.Root>
);
}
Animation states
Four states are available as data attributes to animate the dialog, which enables full control depending on whether the popup is being animated with CSS transitions or animations, JavaScript, or is using the keepMounted
prop.
[data-open]
-open
state istrue
.[data-entering]
- the popup was just inserted to the DOM. The attribute is removed 1 animation frame later. Enables "starting styles" upon insertion for conditional rendering.[data-exiting]
- the popup is in the process of being removed from the DOM, but is still mounted.
Composing a custom React component
Use the render
prop to override the rendered element:
<Dialog.Popup render={<MyCustomDialog />} />
// or
<Dialog.Popup render={(props) => <MyCustomDialog {...props} />} />
Accessibility
Using the <Dialog.Trigger>
sets the required accessibility attributes on the trigger button.
If you prefer controlling the open state differently, you need to apply these attributes on your own:
const [open, setOpen] = React.useState(false);
return (
<div>
<button
aria-haspopup="dialog"
aria-controls="my-popup"
type="button"
onClick={() => setOpen(true)}
>
Open
</button>
<Dialog.Root open={open} onOpenChange={setOpen}>
<Dialog.Popup id="my-popup">
<Dialog.Title>Demo dialog</Dialog.Title>
<Dialog.Close>Close</Dialog.Close>
</Dialog.Popup>
</Dialog.Root>
</div>
);
API Reference
DialogBackdrop
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
keepMounted | bool | false | If true , the backdrop element is kept in the DOM when closed. |
render | union | A function to customize rendering of the component. |
DialogClose
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
render | union | A function to customize rendering of the component. |
DialogDescription
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
render | union | A function to customize rendering of the component. |
DialogPopup
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
container | union | The container element to which the popup is appended to. | |
finalFocus | custom | Determines an element to focus after the dialog is closed. If not provided, the focus returns to the trigger. | |
initialFocus | union | Determines an element to focus when the dialog is opened. It can be either a ref to the element or a function that returns such a ref. If not provided, the first focusable element is focused. | |
keepMounted | bool | false | If true , the dialog element is kept in the DOM when closed. |
render | union | A function to customize rendering of the component. |
DialogRoot
Prop | Type | Default | Description |
---|---|---|---|
animated | bool | true | If true , the dialog supports CSS-based animations and transitions. It is kept in the DOM until the animation completes. |
defaultOpen | bool | Determines whether the dialog is initally open. This is an uncontrolled equivalent of the open prop. | |
dismissible | bool | true | Determines whether the dialog should close when clicking outside of it. |
modal | bool | true | Determines whether the dialog is modal. |
onOpenChange | func | Callback invoked when the dialog is being opened or closed. | |
open | bool | Determines whether the dialog is open. |
DialogTitle
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
render | union | A function to customize rendering of the component. |
DialogTrigger
Renders a trigger element that opens the Dialog.
Prop | Type | Default | Description |
---|---|---|---|
className | union | Class names applied to the element or a function that returns them based on the component's state. | |
render | union | A function to customize rendering of the component. |