Applying URL‐Query Filters to an RPC/VIEW That Returns text/html

[patrickmichalina]

Hello PostgREST community,

I’m trying to expose a server-side HTML renderer (either as an RPC or a VIEW) that returns Content-Type: text/html, but still wants to honor the normal PostgREST URL-query language (e.g. ?status=active&order=asc) to filter and sort the underlying data before rendering.

1. Is it possible to “pipe” standard PostgREST filters (eq, lt, order, etc.) into an HTML-rendering RPC or VIEW?
2. If so, how do I define the function signature or VIEW so that PostgREST recognizes and projects those filters onto the underlying source table?
3. Are there examples of using an RPC that takes a JSONB filter object, applies it in SQL, then returns rendered HTML?
4. Or do I need to build a JSON-returning view, let PostgREST filter it, and then render HTML in a second step?

Any pointers—sample SQL, recommended patterns, config settings—would be greatly appreciated!

Thanks in advance

[steve-chavez]

Hey @patrickmichalina,

I haven't tried it, but it looks like it could work with a custom aggregate for HTML. There is an example here.

A rough idea assuming you want to render an HTML table:

• Have a transition (sfunc) that appends the <tr>some row</tr> for each row.
• A finalfunc (check the docs on bom_csv_final) that finally forms the HTML table, having the <table>, headers, etc. with the previously aggregated contents as table body.

This should allow you to order and filter normally.

Let me know if it works.

[patrickmichalina]

@steve-chavez thanks for the tips. Perhaps I didn't do it right but it still ended up with outputs that looked kind of like

{
  "html": "....valid html here..."
}

The issue is that when applying filters in the url, the columns that drive that HTML generation are never exposed, and I get "no column 'xyz' defined". The only column that is defined is the "html" property on that output json.

[wolfgangwalther]

Perhaps I didn't do it right but it still ended up with outputs that looked kind of like

You'll need to show us what you did. It doesn't look like you created an aggregate function returning a domain-mimetype.