WordPress как на ладони
Недорогой хостинг для сайтов на WordPress: wordpress.jino.ru
функция не описана

WP::send_headers() WP 2.0.0

Sends additional HTTP headers for caching, content type, etc.

Sets the Content-Type header. Sets the 'error' status (if passed) and optionally exits. If showing a feed, it will also send Last-Modified, ETag, and 304 status if needed.

Это метод класса: WP

Хуки из метода
Возвращает

Null. Ничего.

Использование

$WP = new WP();
$var = $WP->send_headers();

Список изменений

С версии 2.0.0 Введена.
С версии 4.4.0 X-Pingback header is added conditionally after posts have been queried in handle_404().

Код WP::send headers: wp-includes/class-wp.php WP 5.3.2

<?php
public function send_headers() {
	$headers       = array();
	$status        = null;
	$exit_required = false;

	if ( is_user_logged_in() ) {
		$headers = array_merge( $headers, wp_get_nocache_headers() );
	}
	if ( ! empty( $this->query_vars['error'] ) ) {
		$status = (int) $this->query_vars['error'];
		if ( 404 === $status ) {
			if ( ! is_user_logged_in() ) {
				$headers = array_merge( $headers, wp_get_nocache_headers() );
			}
			$headers['Content-Type'] = get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' );
		} elseif ( in_array( $status, array( 403, 500, 502, 503 ) ) ) {
			$exit_required = true;
		}
	} elseif ( empty( $this->query_vars['feed'] ) ) {
		$headers['Content-Type'] = get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' );
	} else {
		// Set the correct content type for feeds
		$type = $this->query_vars['feed'];
		if ( 'feed' == $this->query_vars['feed'] ) {
			$type = get_default_feed();
		}
		$headers['Content-Type'] = feed_content_type( $type ) . '; charset=' . get_option( 'blog_charset' );

		// We're showing a feed, so WP is indeed the only thing that last changed.
		if ( ! empty( $this->query_vars['withcomments'] )
			|| false !== strpos( $this->query_vars['feed'], 'comments-' )
			|| ( empty( $this->query_vars['withoutcomments'] )
				&& ( ! empty( $this->query_vars['p'] )
					|| ! empty( $this->query_vars['name'] )
					|| ! empty( $this->query_vars['page_id'] )
					|| ! empty( $this->query_vars['pagename'] )
					|| ! empty( $this->query_vars['attachment'] )
					|| ! empty( $this->query_vars['attachment_id'] )
				)
			)
		) {
			$wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastcommentmodified( 'GMT' ), false );
		} else {
			$wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastpostmodified( 'GMT' ), false );
		}

		if ( ! $wp_last_modified ) {
			$wp_last_modified = gmdate( 'D, d M Y H:i:s' );
		}

		$wp_last_modified .= ' GMT';

		$wp_etag                  = '"' . md5( $wp_last_modified ) . '"';
		$headers['Last-Modified'] = $wp_last_modified;
		$headers['ETag']          = $wp_etag;

		// Support for Conditional GET
		if ( isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) {
			$client_etag = wp_unslash( $_SERVER['HTTP_IF_NONE_MATCH'] );
		} else {
			$client_etag = false;
		}

		$client_last_modified = empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ? '' : trim( $_SERVER['HTTP_IF_MODIFIED_SINCE'] );
		// If string is empty, return 0. If not, attempt to parse into a timestamp
		$client_modified_timestamp = $client_last_modified ? strtotime( $client_last_modified ) : 0;

		// Make a timestamp for our most recent modification...
		$wp_modified_timestamp = strtotime( $wp_last_modified );

		if ( ( $client_last_modified && $client_etag ) ?
				( ( $client_modified_timestamp >= $wp_modified_timestamp ) && ( $client_etag == $wp_etag ) ) :
				( ( $client_modified_timestamp >= $wp_modified_timestamp ) || ( $client_etag == $wp_etag ) ) ) {
			$status        = 304;
			$exit_required = true;
		}
	}

	/**
	 * Filters the HTTP headers before they're sent to the browser.
	 *
	 * @since 2.8.0
	 *
	 * @param string[] $headers Associative array of headers to be sent.
	 * @param WP       $this    Current WordPress environment instance.
	 */
	$headers = apply_filters( 'wp_headers', $headers, $this );

	if ( ! empty( $status ) ) {
		status_header( $status );
	}

	// If Last-Modified is set to false, it should not be sent (no-cache situation).
	if ( isset( $headers['Last-Modified'] ) && false === $headers['Last-Modified'] ) {
		unset( $headers['Last-Modified'] );

		if ( ! headers_sent() ) {
			header_remove( 'Last-Modified' );
		}
	}

	if ( ! headers_sent() ) {
		foreach ( (array) $headers as $name => $field_value ) {
			header( "{$name}: {$field_value}" );
		}
	}

	if ( $exit_required ) {
		exit();
	}

	/**
	 * Fires once the requested HTTP headers for caching, content type, etc. have been sent.
	 *
	 * @since 2.1.0
	 *
	 * @param WP $this Current WordPress environment instance (passed by reference).
	 */
	do_action_ref_array( 'send_headers', array( &$this ) );
}