Create a simple Caching CRUD application for managing a list of books

CodeIgniter4 is a PHP framework that provides tools for building web applications quickly and efficiently. One of the features it offers is caching, which can significantly improve the performance of your application by storing frequently used data in a cache and retrieving it without the need for repeated database queries or expensive computations. In this explanation, I’ll guide you through setting up a sample CRUD (Create, Read, Update, Delete) project in CodeIgniter4 with caching.

Let’s assume you want to create a simple CRUD application for managing a list of books. We’ll implement caching for the list of books to demonstrate the concept.

Step 1: Setup and Installation

1. Install CodeIgniter4 by following the official installation guide: https://codeigniter.com/user_guide/installation/index.html

Step 2: Create the Database and Table

Assuming you have a MySQL database named “library” and a table named “books” with fields: id, title, author, published_year.

Step 3: Configure the Database

Open the app/Config/Database.php file and configure your database connection settings.

public $default = [
    'DSN'      => '',
    'hostname' => 'localhost',
    'username' => 'your_username',
    'password' => 'your_password',
    'database' => 'library',
    'DBDriver' => 'MySQLi',
    'DBPrefix' => '',
    'pConnect' => false,
    'DBDebug'  => (ENVIRONMENT !== 'production'),
    'cacheOn'  => false, // Disable Query Caching for now
    'cacheDir' => '',
    'charset'  => 'utf8',
    'DBCollat' => 'utf8_general_ci',
    'swapPre'  => '',
    'encrypt'  => false,
    'compress' => false,
    'strictOn' => false,
    'failover' => [],
    'port'     => 3306,
];

Step 4: Create Model, Controller, and Views

Let’s assume you’ve created the necessary model, controller, and views to perform CRUD operations on books. You can follow the CodeIgniter documentation or tutorials for creating these components.

Step 5: Implement Caching

Now, let’s implement caching for the list of books in the controller. We’ll use the CodeIgnite4 caching library to achieve this.

In your controller’s method that fetches the list of books (e.g., BooksController.php), add the following code:

public function index()
{
    $cacheKey = 'books_list'; // Define a unique cache key
    $cacheTime = 3600; // Cache expiration time in seconds (1 hour)

    // Try to get the data from cache
    if ($cachedBooks = cache($cacheKey)) {
        $books = $cachedBooks;
    } else {
        // Data not found in cache, fetch from the database
        $books = $this->bookModel->findAll();

        // Store the data in cache
        cache()->save($cacheKey, $books, $cacheTime);
    }

    // Load your view and pass the $books variable
}

In this code, we first check if the data is available in the cache using the specified cache key. If it’s found, we use the cached data; otherwise, we fetch the data from the database, save it in the cache, and then use it. This approach reduces the need for repeated database queries and improves performance.

Remember that caching should be used judiciously, as cached data might become stale if not managed properly. You can invalidate cache when new books are added, updated, or deleted.

This example demonstrates how to implement caching for a list of books in a CodeIgniter4 CRUD project. You can extend this concept to other parts of your application where caching can improve performance.