uo_tincanny_file_motified_http_status_code

Description

Usage

add_filter( 'uo_tincanny_file_motified_http_status_code', 'your_function_name', 10, 1 );

Return Value

The filtered value.

Examples

/**
 * Example of modifying the HTTP status code for unmodified files.
 *
 * This filter allows you to change the default 304 Not Modified
 * status code to something else if needed, for specific scenarios.
 * For example, you might want to return a 200 OK with an empty body
 * in some edge cases, though 304 is standard.
 */
add_filter( 'uo_tincanny_file_motified_http_status_code', 'my_custom_unmodified_file_status', 10, 1 );

function my_custom_unmodified_file_status( $http_status_code ) {
	// In most cases, you'll want to return the original status code
	// or a standard one like 304. This is just an example of how
	// you *could* change it.

	// For instance, if you wanted to always return 200 OK (not recommended
	// for performance and caching) if the client's ETag matches,
	// you would modify the logic in the source file accordingly.
	// This filter is placed *after* the check, so it receives the
	// intended status code from the original logic.

	// Let's add a hypothetical condition: if the file size is very small,
	// maybe we don't want to send a 304, but this is a very unusual case.
	// We need access to the file path, which this filter doesn't directly provide.
	// Therefore, a more realistic use case is to simply return the default or
	// a known alternative.

	// For demonstration, let's say we want to default to 304, but if a specific
	// query parameter is present in the request, we want to force a 200.
	// This requires checking $_GET, which is available globally.
	if ( isset( $_GET['force_refresh'] ) && 'true' === $_GET['force_refresh'] ) {
		return 200; // Force a 200 OK status code
	}

	// Otherwise, return the original status code (which is 304 by default)
	return $http_status_code;
}

Placement

This code should be placed in the functions.php file of your active theme, a custom plugin, or using a code snippets plugin.

Source Code

src/core/tin-canny-protection.php:173

private function set_headers() {

		$headers = array(
			// Set content type
			'Content-Type' => 'Content-Type: ' . $this->get_content_type(),
			// Set X-Robots-Tag
			'X-Robots-Tag' => 'X-Robots-Tag: none',
		);

		// Set content length
		if ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS' ) === false ) {
			$headers['Content-Length'] = 'Content-Length: ' . filesize( $this->content_data->complete_path );
		}

		// Set Cache control
		$headers['Cache-Control'] = 'Cache-Control: no-store, no-cache, must-revalidate';
		$headers['Pragma']        = 'Pragma: no-cache';
		$headers['Expires']       = 'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + 100000000 ) . ' GMT';

		// Get and set last modified date
		$last_modified            = gmdate( 'D, d M Y H:i:s', filemtime( $this->content_data->complete_path ) );
		$headers['Last-Modified'] = 'Last-Modified: ' . $last_modified . ' GMT';

		// Create eTag using a md5 hash of the last modified date
		$etag            = '"' . md5( $last_modified ) . '"';
		$headers['ETag'] = 'ETag: ' . $etag;

		// Check if it supports xsendfile
		if ( $this->supports_mod_xsendfile() ) {
			$headers['X-Sendfile'] = 'X-Sendfile: ' . $this->content_data->complete_path;
		}

		$headers = apply_filters( 'uo_tincanny_protection_headers', $headers );

		if ( is_array( $headers ) && ! empty( $headers ) ) {
			foreach ( $headers as $header ) {
				if ( ! empty( $header ) ) {
					header( $header );
				}
			}
		}

		// Get client eTag
		$client_etag = isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ? stripslashes( $_SERVER['HTTP_IF_NONE_MATCH'] ) : false;

		if ( ! isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
			$_SERVER['HTTP_IF_MODIFIED_SINCE'] = false;
		}

		// Get client last modified
		$client_last_modified = trim( $_SERVER['HTTP_IF_MODIFIED_SINCE'] );
		// Get the timestamp
		$client_modified_timestamp = $client_last_modified ? strtotime( $client_last_modified ) : 0;

		// Make a timestamp for our most recent modification
		$modified_timestamp = strtotime( $last_modified );

		// Check if the client data is defined
		$is_client_data_defined = $client_last_modified && $client_etag;
		// Check if the client has a more recent change to the file than the file in the server
		$client_has_more_recent_modification = $client_modified_timestamp >= $modified_timestamp;
		// Check if the client has the same eTag
		$client_has_same_etag = $client_etag == $etag;
		// Compare last modified from the file with the last modified from the client
		if ( $is_client_data_defined ? ( $client_has_more_recent_modification && $client_has_same_etag ) : ( $client_has_more_recent_modification || $client_has_same_etag ) ) {
			status_header( apply_filters( 'uo_tincanny_file_motified_http_status_code', 304 ) );
			exit;
		}
	}