How-to guides

Short, focused recipes. Each guide solves one problem and assumes you already know the basics — start with the Tutorials if you don’t.

• Assemble a page in parts
• Stream HTML to a socket
• Stream HTML asynchronously
• Convert a CSV to an HTML table
• Embed binary data with a data: URI
• Lazy children with callables
• Conditional attributes with ABSENT
• Boolean attributes
• Custom tags
• Fragments vs Raw
• Inline and embedded CSS
• Unescaped content in <script> and <style>
• Pre-resolve async data
• Serve HTML fragments to htmx

Recipe index

Building pages

• Assemble a page in parts — share references to nodes and fill them in later.

• Custom tags — emit non-standard tag names without subclassing.

• Fragments vs Raw — group children with no wrapper, or embed pre-rendered HTML safely.

Attributes

• Conditional attributes with ABSENT

• Boolean attributes

• Inline and embedded CSS

Dynamic content

• Lazy children with callables

• Pre-resolve async data

• Unescaped content in <script> and <style>

I/O & streaming

• Stream HTML to a socket

• Stream HTML asynchronously — with tagz.aio, for handlers that await DB/HTTP inline.

• Convert a CSV file to an HTML table

• Embed binary data with a data: URI

Frameworks

• Serve HTML fragments to htmx — minimal aiohttp + htmx demo; a fuller version lives in examples/htmx-asyncio.