components / dialog

Dialog

Modal overlay surface with focus containment, backdrop dismissal, and tokenized sizing.

Overview

What it is

This section explains the intent of the component before the implementation details.

  • Dialog is the DK modal surface for moments when the user must address a focused task or decision before continuing.
  • It provides clear structure, focus containment, and predictable close behavior.

Aliases

modal

Decision guide

How to choose it

Use these notes to decide quickly whether this is the right DK component for the job.

Decision guide

  • Choose Dialog when the interaction should feel deliberate, documented, and reusable across product surfaces.
  • If the scenario is more specialized than the current Dialog contract, prefer a simpler component or build a dedicated workflow on top of the lower-level DK primitives.

Do

  • Keep the Dialog label, value, or status language direct enough to scan quickly.
  • Use the documented size and state recipes instead of inventing one-off variants in product code.

Do not

  • Do not hide the main purpose of Dialog behind decorative copy or overloaded surface treatments.
  • Do not stretch Dialog into a workflow it was not designed to handle just because the visuals are close.

Usage

When to use

Prefer these situations when choosing this component.

  • Use Dialog for blocking confirmations, brief forms, or focused review tasks.
  • Use title and description to explain why the modal appeared and what the user is deciding.

Usage

When not to use

These patterns are better served by a different component or a simpler surface.

  • Do not use Dialog for passive status messages; use Alert or Toast.
  • Do not use Dialog for long side workflows that should preserve more surrounding context; use Drawer.

Anti-patterns

  • Using Dialog as a generic layout container instead of a purpose-built interaction or content surface.
  • Forking the documented recipe in product code instead of extending the shared DK contract.

Migration notes

  • Migrate legacy dialog usage by mapping existing variants and states onto the documented DK props before porting any custom styling.
  • Treat the docs examples as the reference contract for accessibility and event behavior during adoption.

Anatomy

Structural parts

The anatomy explains which pieces matter to the recipe and accessibility model.

open affordance

trigger

Control that opens the dialog.

modal container

surface

Contains title, description, body, and footer.

actions row

footer

Optional closing actions area.

API

Public interface

The docs contract distinguishes props, DOM events, and slots so integration behavior is explicit.

Props

NameTypeDefaultDescription
openbooleanfalseControlled open state.
size'sm' | 'md' | 'lg''md'Chooses the dialog size recipe.
titlestring—Dialog title.
descriptionstring—Optional supporting explanation.
closeOnEscapebooleantrueAllows Escape to close the dialog.
closeOnOutsidePressbooleantrueAllows outside press dismissal.
onOpenChange(detail: { open: boolean }) => void—Callback fired when the dialog opens or closes.
themeThemeContract—Overrides the compiled DK theme used to resolve tokens and recipes for this component.

Events

NamePayloadDescription
openchange{ open: boolean }Fires when an overlay-style component opens or closes through user interaction.

Slots

NameDescription
triggerOptional trigger content.
defaultDialog body content.
footerOptional footer actions.

Recipes

Variants, sizes, and states

These notes summarize the intended recipe surface rather than exposing raw implementation detail first.

Variants

  • modal: Centered blocking overlay surface.

Sizes

  • sm: Compact modal
  • md: Default modal
  • lg: Larger modal for more content

States

  • closed: Dialog is hidden
  • open: Dialog is visible and focus-contained

Accessibility

Accessibility contract

This is the behavior the component promises to assistive tech and keyboard users today.

Semantics

  • Uses overlay semantics that reflect whether the surface is modal, contextual, or advisory.
  • Uses dialog semantics with labeled title and optional description.

Keyboard

  • Supports Escape dismissal when allowed.
  • Returns focus to the trigger after closing.
  • Focus moves into the dialog on open and returns to the trigger on close.

Screen readers

  • Announces the overlay surface with its title, description, or tooltip content as available.

Checklist

  • Verify the visible label or title still produces a clear accessible name.
  • Verify focus remains obvious in every supported state and size.
  • Verify disabled, selected, and error states do not rely on color alone.

Implementation

Tokens and slot vars

This section shows the representative compiled slot variables that the runtime consumes for the selected design system.

root

--dk-motion-duration
200ms

backdrop

--dk-dialog-backdrop-bg
rgba(15, 23, 42, 0.45)

surface

--dk-dialog-surface-bg
#f2f5fb
--dk-dialog-surface-fg
#16181c
--dk-dialog-surface-border
#95989d
--dk-dialog-surface-radius
clamp(1.333rem, 1.2222rem + 0.494vw, 1.667rem)
--dk-dialog-surface-shadow
0 10px 15px rgba(0, 0, 0, 0.06), 0 4px 6px rgba(0, 0, 0, 0.04)
--dk-dialog-surface-width
420px
--dk-dialog-surface-padding
clamp(1.778rem, 1.6296rem + 0.658vw, 2.222rem)

title

--dk-dialog-title-size
clamp(1.778rem, 1.6296rem + 0.658vw, 2.222rem)
--dk-dialog-title-weight
650

description

--dk-dialog-description-size
clamp(1.333rem, 1.2222rem + 0.494vw, 1.667rem)

footer

--dk-dialog-footer-gap
clamp(0.75rem, 0.6875rem + 0.278vw, 0.938rem)

Implementation notes

  • Dialog is modal-only in this contract; non-modal instructional surfaces should use Popover or Drawer.

Implementation checklist

  • Use the public component API first and only drop to lower-level primitives when the component contract genuinely does not fit.
  • Keep theme overrides token-driven so proofs and recipes stay meaningful.
  • Verify the shipped examples and proof fixtures still represent the real product scenario you are implementing.

Examples

Copy-paste examples

Each example is intentionally practical, grouped by starter, common pattern, and edge-case coverage.

Examples
3
Depth
expanded

Starter

1 example

starter

Starter: confirm action

A standard confirm/review modal.

Copy snippet

<Dialog title="Release notes" description="Confirm the publication details before shipping."><svelte:fragment slot="trigger">Open dialog</svelte:fragment>Review the release details.</Dialog>

Common patterns

1 example

common

Common: explicit footer actions

Use a footer when the decision needs multiple clear next steps.

Copy snippet

<Dialog title="Confirm delete"><svelte:fragment slot="footer"><Button variant="ghost">Cancel</Button><Button variant="destructive">Delete</Button></svelte:fragment>Review the consequences before continuing.</Dialog>

Edge cases

1 example

edge

Edge: controlled modal state

Control open state when product logic owns the workflow.

Copy snippet

<Dialog open={isOpen} onOpenChange={(detail) => isOpen = detail.open} title="Release notes">Review details</Dialog>

Verification

Curated proof fixtures

Proofs stay visible in the docs so the system shows what it can guarantee, not just what it can render.

default (size=sm)

pass

size=sm

  • Contrast: 98.5 Lc
  • Layout: 0 / 360, 420, 560

default (size=md)

pass

size=md

  • Contrast: 98.5 Lc
  • Layout: 0 / 360, 420, 560

large

pass

size=lg

  • Contrast: 98.5 Lc
  • Layout: 0 / 360, 420, 560