`Container`¶

Constrain and center a readable block of page content.

Phase 0.61 published surface

This additive contract is implemented and verified for the published 0.61.x Supported surface. See RELEASE_0_61.


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

Live demo¶

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This readable block stays centered with a bounded width.

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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 Container, Heading, Text
component = Container(Heading('Profile', level=1), Text('Manage your public details.'), query='inline-size', name='profile')

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

How it works¶

The component emits an addressable div and always retains the hedron-container theme hook. In 0.59, query='inline-size' opts the boundary into container-aware responsive styling and name= adds a validated named-container marker. Phase 0.61 adds finite width, alignment, and spacing markers without changing the default viewport behavior. Positional nodes and children= use the same normalization rules, and an application class augments rather than disables the built-in layout.

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¶

Container(*nodes, children=None, id=None, class_=None, query='none', name=None, max_width=None, align=None, padding=None)

Parameter	Type	Meaning
`nodes`	`NodeLike`	Positional content inside the width constraint.
`children`	`NodeLike \| sequence \| None`	Keyword alternative for generated or declarative child lists; combines with positional nodes.
`id`	`str \| None`	Stable DOM target for links, tests, and HTMX swaps.
`class_`	`str \| None`	Application class appended after `hedron-container`; the built-in theme hook is retained.
`query`	`Literal['none', 'inline-size']`	Opt into an inline-size query boundary. Default: `'none'` (existing viewport behavior).
`name`	`str \| None`	Validated container name, valid only with `query='inline-size'`.
`max_width`	`xs \| sm \| md \| lg \| xl \| full \| None`	Finite readable-width token.
`align`	`start \| center \| end \| None`	Inline alignment inside the containing block.
`padding`	`none \| sm \| md \| lg \| None`	Theme-owned block spacing token.

Composition and backend behavior¶

Keep Container 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.

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

Accessibility¶

A container has no semantics of its own, so keep headings and landmarks inside it.

Security¶

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

Common mistakes¶

Do not use Container as a substitute for Main or Section. Do not assume query='inline-size' is a viewport breakpoint; use the existing responsive maps when viewport semantics are intended.
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

Container¶