Implemented In-Memory CRUD API for Book Management in Flask

Dockerfile

@@ -0,0 +1,21 @@
+# Use an official Python runtime as the base image
+FROM python:3.11-slim
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Copy the current directory contents into the container at /app
+COPY . /app
+
+# Install any needed packages specified in requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Expose port 5000 for Flask to run on
+EXPOSE 5000
+
+# Define the environment variable for Flask
+ENV FLASK_APP=app.py
+ENV FLASK_RUN_HOST=0.0.0.0
+
+# Run the Flask application
+CMD ["flask", "run"]

README.md

@@ -17,10 +17,76 @@ Your task is to implement simple CRUD API using a simple in-memory data structur
   - _title_ - book's title (string, **required**)
   - _author_ - book's auther name (string, **required**)
   - _price_ - book's price (int, **required**)
-  - _category_ - book's category (_array_ of _strings_, **required**) 
+  - _category_ - book's category (_array_ of _strings_, **required**)
   - _publication_year_ - date and year of the book's publicaiton (date, **required**)
 
 
 - Requests to non-existing endpoints (e.g. _/some-non/existing/resource_) should be handled.
 - Internal server errors should be handled and processed correctly.
 - Make sure the api is accesible by frontend apps hosted on a different domain (cross-site resource sharing)
+
+
+---
+---
+
+# Simple Doc for Flask App [Version 1]
+
+A lightweight Flask application that runs entirely in-memory, no database required! This app provides basic book management functionality with RESTful API routes.
+
+## Features:
+- Add, update, delete, and fetch books.
+- Runs in-memory (no database required).
+- Dockerized for easy deployment.
+
+## Getting Started:
+
+### Prerequisites:
+- [Python 3.8+](https://www.python.org/downloads/)
+- [Docker](https://www.docker.com/)
+
+### Run Locally:
+
+1. **Clone the repository**
+   ```bash
+   git clone https://github.com/Yohannes90/flask-crud-challenge.git
+   cd flask-crud-challenge
+   ```
+
+2. **Install dependencies**
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+3. **Run the app**
+   ```bash
+   python -m flask --app app run
+   ```
+
+4. **Access the API**
+   - Open your browser or Postman and visit: `http://127.0.0.1:5000/books`
+
+### Run with Docker:
+
+1. **Build the Docker image**
+   ```bash
+   docker build -t flask-app .
+   ```
+
+2. **Run the Docker container**
+   ```bash
+   docker run -p 5000:5000 flask-app
+   ```
+
+3. **Access the API**
+   - Open your browser or Postman and visit: `http://localhost:5000/books`
+
+---
+
+## API Endpoints:
+- **GET** `/books` - Retrieve all books.
+- **GET** `/books/:id` - Retrieve a specific book by ID.
+- **POST** `/books` - Add a new book.
+- **PUT** `/books/:id` - Update an existing book by ID.
+- **DELETE** `/books/:id` - Delete a book by ID.
+
+---

app.py

@@ -0,0 +1,17 @@
+from flask import Flask
+from flask_cors import CORS
+from routes import book_routes
+from config import DevelopmentConfig
+
+
+app = Flask(__name__)
+CORS(app)
+
+# Register the blueprints
+app.register_blueprint(book_routes)
+
+app.config.from_object(DevelopmentConfig)
+
+
+if __name__ == "__main__":
+    app.run()

config.py

@@ -0,0 +1,3 @@
+class DevelopmentConfig:
+    DEBUG = True
+    CORS_HEADERS = 'Content-Type'

models.py

@@ -0,0 +1,11 @@
+from uuid import uuid4
+
+
+class Book:
+    def __init__(self, title, author, price, category, publication_year):
+        self.id = str(uuid4())
+        self.title = title
+        self.author = author
+        self.price = price
+        self.category = category
+        self.publication_year = publication_year

requirements.txt

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+Flask==3.0.3
+Flask-Cors==5.0.0
+Werkzeug==3.0.4

routes.py

@@ -0,0 +1,97 @@
+from flask import Blueprint, jsonify, request
+from uuid import uuid4
+from validators import validate_book
+
+
+book_routes = Blueprint('book_routes', __name__)
+
+# In-memory data structure
+books = []
+
+
+@book_routes.route('/books', methods=['GET'])
+def get_all_books():
+    return jsonify(books), 200
+
+
+@book_routes.route('/books/<string:book_id>', methods=['GET'])
+def get_book_by_id(book_id):
+    for book in books:
+        if book['id'] == book_id:
+            return jsonify(book), 200
+
+    return jsonify({"error": "Book not found"}), 404
+
+
+@book_routes.route('/books', methods=['POST'])
+def add_book():
+    data = request.get_json()
+
+    if not data:
+        return jsonify({"error": "No data provided."}), 400
+
+    validation_error = validate_book(data)
+    if validation_error:
+        return jsonify(validation_error), validation_error[1]
+
+    new_book = {
+        'id': str(uuid4()),
+        'title': data['title'],
+        'author': data['author'],
+        'price': data['price'],
+        'category': data['category'],
+        'publication_year': data['publication_year']
+    }
+    books.append(new_book)
+
+    return jsonify(new_book), 201
+
+
+@book_routes.route('/books/<string:book_id>', methods=['PUT'])
+def update_book_by_id(book_id):
+    data = request.get_json()
+
+    if not data:
+        return jsonify({"error": "No data provided."}), 400
+
+    validation_error = validate_book(data)
+    if validation_error:
+        return jsonify(validation_error), validation_error[1]
+
+    for book in books:
+        if book['id'] == book_id:
+            book.update(data)
+            return jsonify(book), 200
+
+    return jsonify({"error": "Book not found"}), 404
+
+
+@book_routes.route('/books/<string:book_id>', methods=['DELETE'])
+def delete_book_by_id(book_id):
+    for book in books:
+        if book['id'] == book_id:
+            books.remove(book)
+            return jsonify({"message": "Book deleted"}), 200
+
+    return jsonify({"error": "Book not found"}), 404
+
+
+@book_routes.errorhandler(404)
+def not_found(error):
+    return jsonify({"error": "Resource not found"}), 404
+
+
+@book_routes.errorhandler(400)
+def bad_request(error):
+    return jsonify({"error": "Bad Request", "message": str(error)}), 400
+
+
+@book_routes.errorhandler(500)
+def internal_error(error):
+    return jsonify({"error": "An internal error occurred"}), 500
+
+
+
+
+
+

validators.py

@@ -0,0 +1,30 @@
+from datetime import datetime
+
+
+# Validate the book data
+def validate_book(data):
+    required_fields = ['title', 'author', 'price', 'category', 'publication_year']
+    for field in required_fields:
+        if field not in data:
+            return {"error": f"'{field}' is a required field."}, 400
+
+    if not isinstance(data['title'], str):
+        return {"error": "'title' must be a string."}, 400
+
+    if not isinstance(data['author'], str):
+        return {"error": "'author' must be a string."}, 400
+
+    if not isinstance(data['price'], int):
+        return {"error": "'price' must be an integer."}, 400
+
+    if not isinstance(data['category'], list) or not all(isinstance(cat, str) for cat in data['category']):
+        return {"error": "'category' must be an array of strings."}, 400
+
+    try:
+        pub_year = int(data['publication_year'])
+        if pub_year > datetime.now().year:
+            return {"error": "'publication_year' cannot be in the future."}, 400
+    except ValueError:
+        return {"error": "'publication_year' must be a valid year (integer)."}, 400
+
+    return None