process.js - Yatate

Plain JavaScript. Declares every output page, decides which layout partials get composited onto which page, and can prepare presentation data for blocks. Required - a project with no process.js, or one that never declares a page, generates nothing at all. Runs after validate.js passes.

Name	Type	Meaning
`inputs`	object	Same submitted-data map `validate.js` sees. A new or reassigned property forwards to every block.
`addPage(properties)`	function	Declares one output page - blank or backed by a PDF resource file. Page number = position in the call sequence.
`overlay(filename[, page])`	function	Composites a partial onto `page` (default `1`, an `addPage()`-declared page number). Callable more than once, targeting different pages.

addPage({ width: 210, height: 297, backgroundColor: "#FFFFFF" }); // page 1

overlay("overlay.json");
if (inputs["is_certified"]) {
  overlay("certified_badge.json");   // only when the checkbox is on
}

See JavaScript API for the full function reference - addPage()/overlay()'s complete property/transform shapes, plus every other available function (page refinement, project introspection, formatting).

Handing computed data to blocks

Assign a new inputs property instead of writing a long formula inline in a block:

inputs.gridData = [];
for (var i = 0; i < inputs.options.length; i++) {
  var o = inputs.options[i];
  inputs.gridData.push({ text: o.description }, { text: '$' + o.price });
}

A block then references it: "data": "inputs.gridData". See Grid for the full pattern.

process.js and a block's own template run in separate scripting contexts - the only bridge is inputs. A plain local variable (var x = 5;) never reaches a block.