TypeScript Lab: HTML Escape Machine

LAB / EXPLORATION

TypeScript Lab: HTML Escape Machine

Planned

LAB 028 — Data Transformation
Display the difference between raw and escaped markup.

LAB TypeScript Lab: HTML Escape Machine Preview coming soon

LAB 028

TypeScript Lab: HTML Escape Machine

Concept

Escaping converts dangerous markup characters into safe text entities.

Concept

Escaping converts dangerous markup characters into safe text entities.

Objective & Explanation

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

Learning Target

Objective

Display the difference between raw and escaped markup.

Explanation

Escaping converts dangerous markup characters into safe text entities.

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

Data Layer

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

Sandbox Source

src/generator/generate.ts → escapeHtml(), attr()

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.

function escapeHtml(value: string): string {
  return value
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;")
    .replace(/'/g, "&#039;");
}

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: display the difference between raw and escaped markup.

Data: None