`Header`¶

Render the semantic header landmark for introductory content.


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

Live demo¶

<header>Header content

Render the semantic `header` landmark for introductory content.

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 Header, Heading, Text
component = Header(Heading('Acme', level=1), Text('Workspace overview'))

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

How it works¶

Header emits a native <header>, preserving semantic navigation instead of using a generic div. Children may be passed individually or as one non-string sequence. Landmark helpers are real typed classes with an allowlisted attribute set.

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¶

Header(*nodes, children=None, class_=None, id=None, lang=None, dir=None, role=None, aria=None, data=None, ...)

Parameter	Type	Meaning
`nodes`	`NodeLike`	Positional content belonging to this semantic region.
`children`	`NodeLike \| sequence \| None`	Keyword alternative; combines with positional nodes.
`class_`	`str \| None`	Optional authored class name.
`id`	`str \| None`	Stable fragment or target identifier.
`lang / dir / role / title / tabindex / aria / data / hidden`	`allowlisted`	Safe HTML attributes; hostile roles like `presentation` / `none` are rejected.

Composition and backend behavior¶

Keep Header 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.

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

Accessibility¶

Do not nest a page-level header inside main; a section may have its own header when it labels that section.

Security¶

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

Common mistakes¶

A header is not automatically a banner landmark when nested. Choose placement intentionally.
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

Header¶