What is a Heartbeat API in WordPress?

At its core, the Heartbeat API facilitates seamless communication between the server and the browser. This communication is vital for real-time data transfer, enabling various features that improve the functionality and user experience of WordPress sites.

The API operates by establishing a consistent interval, known as a “tick,” which typically occurs every 15 to 120 seconds when a page is loaded.

During these intervals, the API collects data, sends it to the server through an AJAX request using the /wp-admin/admin-ajax.php file, and waits for a response. The server processes this data, prepares a response, and returns it in JSON format.

The client side then receives this data, completing the communication loop.

Key Features Enabled by the Heartbeat API

The Heartbeat API is not just a background process; it actively enhances the WordPress experience by enabling several key features:

Autosaving and Revisions

One of the most significant benefits of the Heartbeat API is its autosaving feature. This function automatically saves drafts and revisions during content creation, providing a safety net against data loss due to unexpected issues like browser crashes or connectivity problems.

Real-time Dashboard Notifications

The API powers real-time dashboard notifications. These notifications keep users informed with the latest updates, ensuring they are always aware of important changes or events on their WordPress site.

Content Locking

In multi-user environments, the Heartbeat API plays a critical role in content management. It prevents simultaneous editing of the same post by different users, thereby avoiding conflicts and ensuring content integrity.

Session Management

The API aids in session management by keeping track of user activities within the WordPress dashboard. This feature is essential for maintaining an orderly and secure working environment within the CMS.

Developer Tools

For developers, the Heartbeat API offers a range of possibilities. It can be used to add real-time features to themes and plugins, enhancing the interactive capabilities of WordPress sites.

Real-time Synchronization

The API ensures that changes made by multiple users on the same post or page are synchronized in real-time. This feature is essential for collaborative work, as it helps prevent confusion and lost edits.

Support for Plugins

Many plugins, especially those requiring real-time data updates like social media feeds or notification systems, rely on the Heartbeat API for accurate and timely information delivery.

Managing the Heartbeat API

While the Heartbeat API is beneficial, it can also lead to high CPU usage if not managed properly. This is because of the frequent server requests it generates. Fortunately, WordPress offers tools for managing this API effectively.

Using the Heartbeat Control Plugin

The Heartbeat Control plugin by WP Rocket is a user-friendly tool for managing the Heartbeat API. It offers options to enable, disable, or modify the API’s behavior.

This plugin also allows setting rules for specific locations, such as the Dashboard, Frontend, or Post Editor. Managing the API through this plugin is straightforward:

Install the Heartbeat Control plugin from the WordPress plugin repository.
Activate the plugin and navigate to “Settings” -> “Heartbeat Control Settings.”
In the settings, choose your preferred Heartbeat behavior and specify the locations where these settings should apply.

Manually Editing the Code

For users who prefer manual control or wish to avoid using additional plugins, modifying the Heartbeat API can be achieved by adding code to the theme’s functions.php file. For instance, to change the interval of the Heartbeat ticks:

function change_frequency_of_heartbeat_settings( $settings ) {
$settings['interval'] = 100; // Modify the interval as needed, within 15-120 seconds
return $settings;
}

add_filter( 'heartbeat_settings', 'change_frequency_of_heartbeat_settings' );

This snippet adjusts the frequency of the Heartbeat API, allowing for a more customized experience that balances functionality and server resource utilization.

Heart API