Custom components and packs

Your own component

A component is a Typst function that takes one dictionary. Register it under an id, and every request can use that id:

use renderreport::components::ComponentId;
use renderreport::prelude::*;

let mut engine = Engine::new()?;
engine.components_mut().register(
    ComponentId::new("note-strip"),
    r#"#let note-strip(data) = block(
  width: 100%,
  inset: spacing-3,
  fill: color-accent-soft,
  radius: 4pt,
)[#text(weight: "bold")[#data.label] #data.text]"#
        .to_string(),
);

{ "type": "note-strip", "data": { "label": "Note", "text": "Prices exclude VAT." } }

The function name must equal the id, and the template can use every theme token as a variable. The engine includes the function only in reports that use it. Components that are not in the built-in catalog are laid out keep-together.

From Rust, implement the Component trait (component_id and to_data) for your struct and pass it to add_component like a built-in one.

Template packs

To ship components together with a page layout, themes and assets, put them in a template pack: the engine renders a pack’s components like built-in ones, also inside grid-component and flow-group, and a pack component with a built-in id replaces it.