`Stack`¶

Arrange children vertically with a validated, consistent gap.


Import	`from hedron import Stack`
Distribution	`hedron`
Backend activity	No
Normal render mode	`RenderMode.FRAGMENT`

Live demo¶

Build completed42 seconds agoPreview deployedEnvironment readyReview requested2 teammates notified

The preview is a local docs simulation (not a running Hedron server). Interactive demos show a “Simulated HTMX” trace when applicable.

Basic use¶

from hedron import Button, Heading, Stack, Text

component = Stack(Heading('Settings', level=2), Text('Profile'), Button('Save'), gap='1.25rem')

Compose under Page for full documents, or return from a fragment route for HTMX swaps.

How it works¶

Stack writes layout intent and the validated gap to data attributes consumed by the theme; the shipped theme applies that exact gap without requiring an unsafe inline style. Its built-in class is retained when you add an application class. DOM order is unchanged, so the visual sequence matches reading and keyboard order.

This component's core behavior is server-rendered HTML and does not require a browser runtime. The preview is ordinary semantic HTML, so keyboard, form, link, and disclosure behavior comes from the platform.

Constructor and parameters¶

Stack(*nodes, children=None, gap='1rem', id=None, class_=None)

Parameter	Type	Meaning
`nodes`	`NodeLike`	Positional items in visual and DOM order.
`children`	`NodeLike \| sequence \| None`	Keyword child list; combines with positional nodes.
`gap`	`CSS length`	Validated `rem`, `em`, `px`, or `%` spacing.
`id`	`str \| None`	Stable DOM target for the stack region.
`class_`	`str \| None`	Optional class appended to `hedron-stack`.

Composition and backend behavior¶

Keep Stack at the smallest semantic boundary. Fragment routes should return only the replaced region and preserve stable target IDs across success, validation, empty, loading, and error responses.

This component is primarily presentational; keep any mutation on an explicit action or component route.

Accessibility¶

Keep DOM order meaningful and never use CSS reordering to change the task sequence.

Security¶

Escaping and SafeUrl / TrustedHtml are framework concerns; authorization and data exposure remain application code. Redact secrets before rendering.

Common mistakes¶

Values such as calc(...), viewport units, and arbitrary CSS are rejected; use a supported length token.
Do not copy docs-preview JavaScript into an application server.

Testing¶

from hedron import RenderMode, render

result = render(component, mode=RenderMode.FRAGMENT)
assert result.html
assert not result.diagnostics

All component demos · Built-in API · Testing

Stack¶