validate_plugin_requirements() │ WP 5.2.0

Checks that the current plugin meets the necessary requirements for PHP version, WordPress, and active dependent plugins.

The function reads plugin file data and based on the following headers determines whether the current plugin is compatible with the current versions of WP and PHP:

It is often used within the register_activation_hook() function to prevent the activation of the plugin if the requirements are not met.

Notifications are displayed through WordPress administrative notices (admin notice) — they can be styled or translated.

Changes:

Before WP version 5.3, data was read from the readme.txt file.

Starting from WP version 5.3, readme.txt became an additional file in which these headers can be present.

Since version 5.8.0, readme.txt has been removed from support, and now these headers must be in the main plugin file.

Since version 6.5.0, support for the Requires Plugins header has been added.

Uses: is_wp_version_compatible(), is_php_version_compatible(), get_file_data()

No Hooks.

Returns

true|WP_Error. True if the minimum requirements are met, WP_Error if incompatible.

Usage

validate_plugin_requirements( $plugin );
$plugin(string) (required)

Path to the main plugin file relative to the plugins directory. What is returned by plugin_basename().

IMPORTANT! You need to specify the path to the main plugin file (not the plugin folder name)! If you just specify the plugin name (its folder), the function will always return true!

Examples

0

#1 Checking plugin compatibility

Let's check the compatibility of PHP and WP Versions for Democracy Poll plugin:

To do this, the following code can be put on plugin activation hook:

register_activation_hook( __FILE__, 'myplugin_activate' );

function myplugin_activate(){

	// for the front
	require_once ABSPATH . '/wp-admin/includes/plugin.php'; 

	$plugin = 'democracy-poll/democracy.php';
	$valid  = validate_plugin_requirements( $plugin );

	if( is_wp_error( $valid ) ){

		wp_die( $valid->get_error_message() );
		// Will lead out:
		// Error: Current WordPress and PHP versions do not meet minimum requirements for Democracy Poll.

	}

}

Changelog

Since 5.2.0 Introduced.
Since 5.3.0 Added support for reading the headers from the plugin's main PHP file, with readme.txt as a fallback.
Since 5.8.0 Removed support for using readme.txt as a fallback.
Since 6.5.0 Added support for the 'Requires Plugins' header.

validate_plugin_requirements() code WP 6.8.1

wp-admin/includes/plugin.php 
function validate_plugin_requirements( $plugin ) {
	$plugin_headers = get_plugin_data( WP_PLUGIN_DIR . '/' . $plugin );

	$requirements = array(
		'requires'         => ! empty( $plugin_headers['RequiresWP'] ) ? $plugin_headers['RequiresWP'] : '',
		'requires_php'     => ! empty( $plugin_headers['RequiresPHP'] ) ? $plugin_headers['RequiresPHP'] : '',
		'requires_plugins' => ! empty( $plugin_headers['RequiresPlugins'] ) ? $plugin_headers['RequiresPlugins'] : '',
	);

	$compatible_wp  = is_wp_version_compatible( $requirements['requires'] );
	$compatible_php = is_php_version_compatible( $requirements['requires_php'] );

	$php_update_message = '</p><p>' . sprintf(
		/* translators: %s: URL to Update PHP page. */
		__( '<a href="%s">Learn more about updating PHP</a>.' ),
		esc_url( wp_get_update_php_url() )
	);

	$annotation = wp_get_update_php_annotation();

	if ( $annotation ) {
		$php_update_message .= '</p><p><em>' . $annotation . '</em>';
	}

	if ( ! $compatible_wp && ! $compatible_php ) {
		return new WP_Error(
			'plugin_wp_php_incompatible',
			'<p>' . sprintf(
				/* translators: 1: Current WordPress version, 2: Current PHP version, 3: Plugin name, 4: Required WordPress version, 5: Required PHP version. */
				_x( '<strong>Error:</strong> Current versions of WordPress (%1$s) and PHP (%2$s) do not meet minimum requirements for %3$s. The plugin requires WordPress %4$s and PHP %5$s.', 'plugin' ),
				get_bloginfo( 'version' ),
				PHP_VERSION,
				$plugin_headers['Name'],
				$requirements['requires'],
				$requirements['requires_php']
			) . $php_update_message . '</p>'
		);
	} elseif ( ! $compatible_php ) {
		return new WP_Error(
			'plugin_php_incompatible',
			'<p>' . sprintf(
				/* translators: 1: Current PHP version, 2: Plugin name, 3: Required PHP version. */
				_x( '<strong>Error:</strong> Current PHP version (%1$s) does not meet minimum requirements for %2$s. The plugin requires PHP %3$s.', 'plugin' ),
				PHP_VERSION,
				$plugin_headers['Name'],
				$requirements['requires_php']
			) . $php_update_message . '</p>'
		);
	} elseif ( ! $compatible_wp ) {
		return new WP_Error(
			'plugin_wp_incompatible',
			'<p>' . sprintf(
				/* translators: 1: Current WordPress version, 2: Plugin name, 3: Required WordPress version. */
				_x( '<strong>Error:</strong> Current WordPress version (%1$s) does not meet minimum requirements for %2$s. The plugin requires WordPress %3$s.', 'plugin' ),
				get_bloginfo( 'version' ),
				$plugin_headers['Name'],
				$requirements['requires']
			) . '</p>'
		);
	}

	WP_Plugin_Dependencies::initialize();

	if ( WP_Plugin_Dependencies::has_unmet_dependencies( $plugin ) ) {
		$dependency_names       = WP_Plugin_Dependencies::get_dependency_names( $plugin );
		$unmet_dependencies     = array();
		$unmet_dependency_names = array();

		foreach ( $dependency_names as $dependency => $dependency_name ) {
			$dependency_file = WP_Plugin_Dependencies::get_dependency_filepath( $dependency );

			if ( false === $dependency_file ) {
				$unmet_dependencies['not_installed'][ $dependency ] = $dependency_name;
				$unmet_dependency_names[]                           = $dependency_name;
			} elseif ( is_plugin_inactive( $dependency_file ) ) {
				$unmet_dependencies['inactive'][ $dependency ] = $dependency_name;
				$unmet_dependency_names[]                      = $dependency_name;
			}
		}

		$error_message = sprintf(
			/* translators: 1: Plugin name, 2: Number of plugins, 3: A comma-separated list of plugin names. */
			_n(
				'<strong>Error:</strong> %1$s requires %2$d plugin to be installed and activated: %3$s.',
				'<strong>Error:</strong> %1$s requires %2$d plugins to be installed and activated: %3$s.',
				count( $unmet_dependency_names )
			),
			$plugin_headers['Name'],
			count( $unmet_dependency_names ),
			implode( wp_get_list_item_separator(), $unmet_dependency_names )
		);

		if ( is_multisite() ) {
			if ( current_user_can( 'manage_network_plugins' ) ) {
				$error_message .= ' ' . sprintf(
					/* translators: %s: Link to the plugins page. */
					__( '<a href="%s">Manage plugins</a>.' ),
					esc_url( network_admin_url( 'plugins.php' ) )
				);
			} else {
				$error_message .= ' ' . __( 'Please contact your network administrator.' );
			}
		} else {
			$error_message .= ' ' . sprintf(
				/* translators: %s: Link to the plugins page. */
				__( '<a href="%s">Manage plugins</a>.' ),
				esc_url( admin_url( 'plugins.php' ) )
			);
		}

		return new WP_Error(
			'plugin_missing_dependencies',
			"<p>{$error_message}</p>",
			$unmet_dependencies
		);
	}

	return true;
}

plugin

Plugins, Hooks