Builds

A build reveals a slide one part per click. Order comes from the slide's structure, not from a field: the parts of an ordered primitive show in reading order, and everything else shows from the first click. Slides stay stateless, and the host owns the click counter.

What builds

Primitive	One click reveals
`slideBulletList`	an item
`slideList`	a row
`slidePipeline`	a step; the rail and the `start` chip show from the first click, the `end` chip comes with the last step, and in spans mode a span's bracket and caption with the step it ends on
`slideSequence`	a message; the actors and their lifelines show from the first click
`slideTimeline`	an item; the rail shows from the first click
`slideTranscript`	a turn

A slide embedded with slideRender, slideRenderGrid, or slideAnnotatedRender is a picture of a finished slide and never builds. Hidden parts keep their layout box (visibility: hidden), so nothing moves when one appears.

Only the React and HTML surfaces build. The image, text, Markdown, and Slack surfaces draw the finished slide.

Driving builds from a host

Render with the SLIDE_BUILDS enhancement, count the clicks with slideBuilds, and apply a step with showSlideBuild after each render commits:

		import {
  SLIDE_BUILDS,
  showSlideBuild,
  slideBuilds,
} from '@elastic/isomer-primitives-slides';

const element = runtime.surfaces.react.render(composition, {
  enhancements: [SLIDE_BUILDS],
});
const clicks = slideBuilds(composition, runtime.primitives);
// After the render commits into `root`:
showSlideBuild(root, composition, step, runtime.primitives);
		
	

The html surface takes the same id: runtime.surfaces.html.render(composition, { enhancements: [SLIDE_BUILDS] }). A React host collects the pack's CSS with a Distillate live collection, as embedding shows.

slideBuilds(composition, primitives) is the number of clicks the slide takes. showSlideBuild(root, composition, step, primitives) shows the first step parts and hides the rest; call it again with a lower step to go back. It first shows anything an earlier call hid, so it is safe after React reuses elements across slides. A node whose parts it cannot find stays whole. Both walk only this pack's primitives unless given primitives, which misses a buildable node inside another pack's container. Pass the full inventory, such as runtime.primitives, to both: given different inventories, the count can stop before the parts showSlideBuild hides are shown.

The enhancement adds only node anchors, which is how showSlideBuild finds each node through findNodeElementPairs. It ships no script. A render without the enhancement, or with no ordered primitive, carries no anchors.

Making a primitive build

Add a build.ts beside the primitive that exports a SlideBuild: count(node), and units(owner, node), which returns each part's elements under the primitive's anchored root. Find elements by tag and position, never by class name, since class names are minified. Then wrap the definition in the primitive's index.tsx with withBuild(definePrimitive({ … }), build) from src/builds/types.ts, which types the build against the definition's node. slideBuilds and showSlideBuild find it on the registered definition.