TypeScript Lab: Collapse List Renderer

LAB / EXPLORATION

TypeScript Lab: Collapse List Renderer

Planned

LAB 049 — Rendering & Generation
Turn child records into expandable documentation items.

LAB TypeScript Lab: Collapse List Renderer Preview coming soon

LAB 049

TypeScript Lab: Collapse List Renderer

Concept

Stateful disclosure markup adds details without duplicating source content.

Concept

Stateful disclosure markup adds details without duplicating source content.

Objective & Explanation

What the project should make visible and why the concept matters.

Learning Target

Objective

Turn child records into expandable documentation items.

Explanation

Stateful disclosure markup adds details without duplicating source content.

Project Plan

Structure, technologies, data boundary, and source connection.

Structure

project/
├── package.json
├── tsconfig.json
├── index.html
├── styles.css
└── src/
    └── app.ts

Technologies

TypeScript
HTML
CSS
JSON

Data Layer

Use a small local object, array, or JSON fixture so the transformation stays visible.

Sandbox Source

src/generator/generate.ts → renderStandardChild()

Build Instructions

Build only the focused behavior, then use the visual layer to inspect it.

Setup

Create the standalone project folder and listed files.

Implement

Implement the smallest version that demonstrates the concept.

Run & Inspect

Change one input and observe the visible output change.

Code & Configuration

Starter configuration plus the focused implementation example.

Focused TypeScript

Implement this behavior first, then alter the input.

button.addEventListener("click", () => {
  const panel = document.querySelector("#details") as HTMLElement;
  panel.hidden = !panel.hidden;
  button.setAttribute("aria-expanded", String(!panel.hidden));
});

Starter Configuration

Keep the project independently buildable.

package.json

{
  "type": "module",
  "scripts": { "build": "tsc" },
  "devDependencies": { "typescript": "^7.0.2" }
}

tsconfig.json

{
  "compilerOptions": {
    "rootDir": "./src",
    "outDir": "./dist",
    "target": "ES2022",
    "module": "ES2022",
    "lib": ["ES2022", "DOM"],
    "strict": true,
    "sourceMap": true
  },
  "include": ["src/**/*.ts"]
}

Expected Visual Result

The output is the proof that the concept is working.

Visible Proof

The browser should visibly demonstrate: turn child records into expandable documentation items.

Data: JSON