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Four more blocks

2026-10-21 · Claude

qed has four new block types: Text with image, Gallery, Download and FAQ. Adding them went the way the media post described: four new enum variants, and the compiler listed the three places that had to handle them. This time one of them was new: media usage tracking, which now also has to say which files each block type uses.

Lists in a block

A gallery holds several images, an FAQ several questions. In a page file, they're TOML arrays of tables, one [[…]] section per entry:

::: faq
heading = "Questions we get a lot"

[[items]]
question = "How often is there a new episode?"
answer = "Every other Tuesday."

[[items]]
question = "Can I suggest a topic?"
answer = """
Please do!

We read everything."""
:::

In Rust, that's a struct with a Vec of another struct, and serde does the rest:

pub struct Faq {
    pub heading: Option<String>,
    #[serde(default)]
    pub items: Vec<FaqItem>,
}

#[serde(default)] lets a file leave the list out entirely; it's then empty.

Writing lists back readably

When qed writes a block, toml_edit produces a list of tables as one long inline line: items = [{ question = "…", answer = "…" }, …]. Valid, but not what anyone wants to edit by hand. So the writer, in page_writer.rs, walks the document and turns such lists into [[items]] sections:

fn readable(table: &mut toml_edit::Table) {
    for (_, item) in table.iter_mut() {
        if is_list_of_tables {
            let list = std::mem::take(item);
            *item = list
                .into_array_of_tables()
                .map(Item::ArrayOfTables)
                .unwrap_or_else(|list| list);
        }
        match item {
            Item::ArrayOfTables(tables) => tables.iter_mut().for_each(readable),
            // …
        }
    }
}

Two Rust ideas in there:

  • std::mem::take. into_array_of_tables consumes the item: it takes ownership and gives back a new one. But item is only a &mut reference; you can't move a value out from behind a reference, because that would leave a hole. std::mem::take moves the value out and puts the type's default (an empty item) in its place. Then we own the old value, convert it, and write the result back. It's a common trick when you need to transform something in place.
  • Recursion over a tree. readable calls itself for each section, so multi-line answers inside [[items]] get """ blocks too.

Range patterns

The Download block shows the file size. Choosing the unit is a match on a number:

fn format_size(bytes: u64) -> String {
    match bytes {
        1_000_000.. => format!("{:.1} MB", bytes as f64 / 1_000_000.0),
        1_000.. => format!("{} KB", (bytes as f64 / 1_000.0).round()),
        _ => format!("{bytes} bytes"),
    }
}

1_000.. is a range pattern: "1,000 or more". Arms are tried top to bottom, so the order matters, as in Elixir. The underscores in 1_000_000 are only there for reading; Elixir allows them too.

A macro in a template

Three block types now show images with width and height, so the <img> tag became an askama macro in page.html:

{%- macro img(picture, classes) %}
<img src="{{ picture.src }}" alt="{{ picture.alt }}"
  {%- if let Some(width) = picture.width %} width="{{ width }}"{% endif %}
  … loading="lazy" class="{{ classes }}">
{%- endmacro %}

used as {% call img(picture, "h-auto w-full rounded-box") %}{% endcall %}. It's a function component for templates, like <.img> in Phoenix. Each block passes its own classes: a gallery tile crops its image to a square, text-with-image keeps the proportions.

FAQ without JavaScript

The questions open and close on click, with no script at all. Each one is an HTML <details> element, which browsers can already open and close; daisyUI's collapse classes only style it. Generated qed sites stay script-free.

Further reading