TypeScript Lab: Attribute Inspector

LAB / EXPLORATION

TypeScript Lab: Attribute Inspector

Planned

LAB 069 — DOM & Async
Add and remove HTML attributes while viewing DOM changes.

LAB TypeScript Lab: Attribute Inspector Preview coming soon

LAB 069

TypeScript Lab: Attribute Inspector

Concept

Element attribute APIs control state, semantics, and behavior.

Concept

Element attribute APIs control state, semantics, and behavior.

Objective & Explanation

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

Learning Target

Objective

Add and remove HTML attributes while viewing DOM changes.

Explanation

Element attribute APIs control state, semantics, and behavior.

Project Plan

Structure, technologies, data boundary, and source connection.

Structure

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

Technologies

TypeScript
DOM
HTML
CSS

Data Layer

No persistent data layer. Keep all demonstration values inside the standalone project.

Sandbox Source

src/local-editor/client.ts

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.

const box = document.querySelector("#box") as HTMLElement;

box.setAttribute("data-state", "active");
box.setAttribute("aria-hidden", "false");
box.classList.add("selected");

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: add and remove HTML attributes while viewing DOM changes.

Data: None