Todo API - Golang

Overview

This project is a simple Todo API built using Golang, featuring CRUD operations to manage todo items. It leverages Gorilla Mux for routing and TheDevSaddam Renderer for JSON responses and templating. The API is designed to be minimal yet functional, supporting essential features like creating, updating, retrieving, and deleting todo items. Additionally, it includes graceful server shutdown handling and basic input validation.

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Features & Functionalities

1️⃣ Home Page Rendering

• The API includes a basic homepage using an HTML template (home.tpl).
• The homeHandler function renders this template when a request is made to /.

2️⃣ CRUD Operations

The API provides full CRUD (Create, Read, Update, Delete) functionality:

✅ Create a Todo

• Endpoint: POST /todo
• Function: createTodo
• Request Body: JSON containing title (string).
• Response: Returns the created todo item with a unique id and created_at timestamp.
• Validation: The title field is required.

✅ Fetch All Todos

• Endpoint: GET /todo
• Function: fetchTodos
• Response: Returns all todo items as a JSON array.

✅ Update a Todo

• Endpoint: PUT /todo/{id}
• Function: updateTodo
• Request Body: JSON containing updated title and completed status.
• Response: Updates the todo item if found; returns an error if the ID is invalid.

✅ Delete a Todo

• Endpoint: DELETE /todo/{id}
• Function: deleteTodo
• Response: Removes the specified todo item if found; returns an error if not found.

3️⃣ Error Handling

• Ensures that bad requests (e.g., missing title, incorrect JSON format) return meaningful error messages.
• Uses http.StatusBadRequest for invalid requests and http.StatusNotFound for missing todos.

4️⃣ Graceful Shutdown Handling

• The server listens for os.Interrupt signals and safely shuts down when triggered.
• Uses context.WithTimeout() to allow the server to finish ongoing requests before stopping.

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How It Works (Technical Breakdown)

1️⃣ Setting Up the Renderer

• The renderer.Render instance (rnd) is initialized in the init() function.
• It is used to render templates (home.tpl) and return JSON responses.

2️⃣ Handling API Routes

• Uses mux.NewRouter() to define API endpoints.
• Registers handlers for different HTTP methods (GET, POST, PUT, DELETE).

3️⃣ Storing and Managing Todos

• Uses an in-memory slice ([]todo) to store todo items.
• Each todo item contains:
  • ID (string) – Unique identifier based on timestamp.
  • Title (string) – Task description.
  • Completed (bool) – Task completion status.
  • CreatedAt (time.Time) – Timestamp when the task was created.

4️⃣ Running the HTTP Server

• The server listens on port 9010.
• Uses http.Server with timeouts for better performance and security.
• Logs server start-up and shutdown events.

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How to Run This Project

Prerequisites

Ensure you have the following installed:

• Golang (1.16 or later)
• Git (for version control)

Clone the Repository

git clone <repository-url>
cd <project-folder>

Install Dependencies

go mod tidy

Run the Server

go run main.go

The server will start on http://localhost:9010.

Test API Endpoints

You can use Postman or curl to test the endpoints:

Create a Todo

curl -X POST "http://localhost:9010/todo" -H "Content-Type: application/json" -d '{"title":"Learn Golang"}'

Fetch All Todos

curl -X GET "http://localhost:9010/todo"

Update a Todo

curl -X PUT "http://localhost:9010/todo/{id}" -H "Content-Type: application/json" -d '{"title":"Updated Task", "completed":true}'

Delete a Todo

curl -X DELETE "http://localhost:9010/todo/{id}"

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