Introduction

This project serves as the backend service for the Graph Task Generator, designed to generate tasks involving graphs and export them as PDF files.

Key Features

• Task Generation: Generate tasks with customizable graph parameters.
• Graph Creation: Create and layout graphs using Graphology.
• PDF Export: Export tasks and graphs as PDF files.
• Input Validation: Validate task input data to ensure correctness.
• Error Handling: Handle errors gracefully with custom middleware.

For Developers

Technologies Used

The project leverages a variety of technologies, including:

• Express.js: A flexible Node.js web application framework for creating the server and handling HTTP requests.
• Graphology: A robust and versatile library for graph theory, used for generating and manipulating graphs, as well as creating SVG images from them
• pdf-lib: A powerful library for creating and modifying PDF documents in JavaScript.
• Sharp: A high-performance image processing library used to convert SVG images to PNG format.
• TypeScript: A statically typed superset of JavaScript that enhances code quality and maintainability.

Project Structure

.env
.gitignore
generated_pdf/
    generated_task.pdf
graph_svg/
    graph.svg
package.json
src/
    controllers/
        dataController.ts
    middleware/
        errorHandler.ts
    models/
        taskModel.ts
    routes/
        dataFromFrontend.ts
    server.tsx
    services/
        generateGraph.ts
        generateGraphImage.ts
        generatePDF.ts
        taskService.ts
    utils/
        validationUtils.ts
tsconfig.json

Installation

1. Clone the repository
2. Install dependencies (npm install)
3. Create a .env file in the root directory and add any necessary environment variables.

Scripts

• npm run dev: Start the development server using ts-node.
• npm run build: Compile the TypeScript code to JavaScript.
• npm start: Start the compiled server.

API Endpoints

Generate Task

• URL : /api/generate-task

• Method : POST

• Description : Generates a task with a graph and exports it as a PDF.

• Request Body :

  {
  "taskType": "string",
  "graphNodes": "number",
  "graphEdges": "number",
  "taskTitle": "string",
  "taskText": "string",
  "dateChecked": "boolean",
  "date": "string (optional, ISO format)"
  }
  

• Response :

• Success: Returns the generated PDF file.

• Error: Returns an error message.

Error Handling

Errors are handled by the custom error handler middleware defined in errorHandler.ts.

Validation

Input validation is performed using the utility functions defined in validationUtils.ts.

Graph Generation

Graphs are generated using the functions defined in generateGraph.ts.

PDF Generation

PDF files are generated using the functions defined in generatePDF.ts.

Other

License

This project is licensed under the the Apache License. See the LICENSE file for details.

Author

This project is maintained by Benjámin Bartha-Tóth as part of his MA thesis work at ELTE Eötvös Loránd University (Hungary).