As developers, we frequently find ourselves interacting with various APIs to streamline our workflows, enhance performance and improve the overall user experience. Two of the tools that help us achieve this are the HTTP API and the Transients API. In this blog we will explore both of these, as to how we can incorporate them into our WordPress projects.

The Transients API

The Transients API allows us to store temporary data in the WordPress database with a fixed expiration time. This is perfect for data that doesn’t change frequently like API responses, settings or query results. When we store data as a transient, WordPress automatically delete it once it expires, reducing the need for manual data clean up.

Why Use Transients?

The Transients API is an excellent tool for improving query performance by reducing the number of database queries or even the external API calls. By caching data that does not change often we can reduce server load and speed up the page loads, and improve the overall user experience.

Transients are especially useful for storing API responses, product listings, user preferences or any data that is expensive to fetch or compute but doesn’t change frequently.

Setting and Getting Transients

To work with transients we have a few key functions which we can use—

• set_transient( $transient, $value, $expiration ) – Used to store data as a transient.
• get_transient( $transient ) – Retrieves the data stored in a transient.
• delete_transient( $transient ) – Deletes a specific transient.

// Store data in a transient
set_transient('my_transient', 'This is some data', 3600);

// Retrieve data from the transient
$stored_data = get_transient('my_transient');

if ($stored_data) {
    echo "Transient data: $stored_data";
} else {
    echo "No transient data found.";
}

The HTTP API

The HTTP API in WordPress is a tool that simplifies making HTTP requests, such as GET, POST, PUT, and DELETE. When we need to fetch data from external sources or send data to external servers, the HTTP API is our go-to solution.

GET with Transient Caching

When working with external APIs we often face performance issues. Fetching data from remote servers can be slow and resource intensive, the problem becomes ever worse when the same data is being fetched repeatedly. This is where transient caching becomes invaluable.

The Transients API allows us to store data for a specific period reducing the need for repeated HTTP requests. By combining the HTTP API with transient caching we can ensure that our application only fetches data from external sources when necessary which in turn helps to reduce latency and minimize the load on servers.

$transient_key = 'external_api_data';
$cached_data = get_transient($transient_key);

if (false === $cached_data) {
    // no cache is found so make the HTTP request
    $response = wp_remote_get('https://api.example.com/data');
    
    if (is_wp_error($response)) {
        $error = $response->get_error_message();
        echo "Something went wrong: $error";
    } else {
        // Cache the response
        $cached_data = wp_remote_retrieve_body($response);
        set_transient($transient_key, $cached_data, 12 * HOUR_IN_SECONDS);
        echo "Data fetched successfully: $cached_data";
    }
} else {
    // Use cached data
    echo "Using cached data: $cached_data";
}

Conclusion

The HTTP API and Transients API are two powerful tools that can help us build efficient and high performance WordPress applications. By understanding how to use them effectively—whether its caching GET requests or storing temporary data we can create better sites and all while reducing server load.