`Image`¶

Render an image with a validated source and required alternative text.


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

Live demo¶

Image preview

Meaningful alternative: “The platform team at the meetup.”

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 Image

component = Image('/static/team.jpg', alt='The platform team at the 2026 meetup', width=960, height=540)

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

How it works¶

Image applies the SafeUrl asset policy and always writes the supplied alternative. Supplying intrinsic dimensions lets the browser reserve space before the asset arrives. Loading strategy is not a constructor option on this built-in.

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¶

Image(src, *, alt, width=None, height=None, allow_external=False)

Parameter	Type	Meaning
`src`	`SafeUrl \| str`	Validated asset URL.
`alt`	`str`	Required text alternative; use an empty string for decorative images.
`width / height`	`int \| None`	Intrinsic dimensions to reduce layout shift.
`allow_external`	`bool`	Permit a validated external asset origin.

Composition and backend behavior¶

Keep Image 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¶

Describe the image's purpose in context; use alt='' only when nearby content already conveys everything.

Security¶

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

Common mistakes¶

Do not enable external assets casually: review privacy, CSP, availability, and tracking implications.
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

Image¶