WP::send_headers()

Description

Hooks fired · 2

2 hooks fire while WP::send_headers() runs, in this order:

1. 1
   apply_filters( wp_headers )filterline 563 (+128 into the body)

   Filters the HTTP headers before they're sent to the browser.

2. 2
   do_action( send_headers )actionline 595 (+160 into the body)

   Fires once the requested HTTP headers for caching, content type, etc. have been sent.

Uses · 16

• is_user_logged_in()Determines whether the current visitor is a logged in user.
• wp_get_nocache_headers()Gets the HTTP header information to prevent caching.
• get_option()Retrieves an option value based on an option name.
• get_default_feed()Retrieves the default feed.
• feed_content_type()Returns the content type for specified feed type.
• str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
• mysql2date()Converts given MySQL date string into a different format.
• get_lastpostmodified()Gets the most recent time that a post on the site was modified.
• get_lastcommentmodified()Retrieves the date the last comment was modified.
• wp_unslash()Removes slashes from a string or recursively removes slashes from strings within an array.
• is_singular()Determines whether the query is for an existing single post of any post type (post, attachment, page, custom post types).
• pings_open()Determines whether the current post is open for pings.

Used by · 1

• WP::main()Sets up all of the variables required by the WordPress environment.

Source

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435	public function send_headers() {436		global $wp_query;437 438		$headers       = array();439		$status        = null;440		$exit_required = false;441		$date_format   = 'D, d M Y H:i:s';442 443		if ( is_user_logged_in() ) {444			$headers = array_merge( $headers, wp_get_nocache_headers() );445		} elseif ( ! empty( $_GET['unapproved'] ) && ! empty( $_GET['moderation-hash'] ) ) {446			// Unmoderated comments are only visible for 10 minutes via the moderation hash.447			$expires = 10 * MINUTE_IN_SECONDS;448 449			$headers['Expires']       = gmdate( $date_format, time() + $expires );450			$headers['Cache-Control'] = sprintf(451				'max-age=%d, must-revalidate',452				$expires453			);454		}455		if ( ! empty( $this->query_vars['error'] ) ) {456			$status = (int) $this->query_vars['error'];457 458			if ( 404 === $status ) {459				if ( ! is_user_logged_in() ) {460					$headers = array_merge( $headers, wp_get_nocache_headers() );461				}462 463				$headers['Content-Type'] = get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' );464			} elseif ( in_array( $status, array( 403, 500, 502, 503 ), true ) ) {465				$exit_required = true;466			}467		} elseif ( empty( $this->query_vars['feed'] ) ) {468			$headers['Content-Type'] = get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' );469		} else {470			// Set the correct content type for feeds.471			$type = $this->query_vars['feed'];472			if ( 'feed' === $this->query_vars['feed'] ) {473				$type = get_default_feed();474			}475 476			$headers['Content-Type'] = feed_content_type( $type ) . '; charset=' . get_option( 'blog_charset' );477 478			// We're showing a feed, so WP is indeed the only thing that last changed.479			if ( ! empty( $this->query_vars['withcomments'] )480				|| str_contains( $this->query_vars['feed'], 'comments-' )481				|| ( empty( $this->query_vars['withoutcomments'] )482					&& ( ! empty( $this->query_vars['p'] )483						|| ! empty( $this->query_vars['name'] )484						|| ! empty( $this->query_vars['page_id'] )485						|| ! empty( $this->query_vars['pagename'] )486						|| ! empty( $this->query_vars['attachment'] )487						|| ! empty( $this->query_vars['attachment_id'] )488					)489				)490			) {491				$wp_last_modified_post    = mysql2date( $date_format, get_lastpostmodified( 'GMT' ), false );492				$wp_last_modified_comment = mysql2date( $date_format, get_lastcommentmodified( 'GMT' ), false );493 494				if ( strtotime( $wp_last_modified_post ) > strtotime( $wp_last_modified_comment ) ) {495					$wp_last_modified = $wp_last_modified_post;496				} else {497					$wp_last_modified = $wp_last_modified_comment;498				}499			} else {500				$wp_last_modified = mysql2date( $date_format, get_lastpostmodified( 'GMT' ), false );501			}502 503			if ( ! $wp_last_modified ) {504				$wp_last_modified = gmdate( $date_format );505			}506 507			$wp_last_modified .= ' GMT';508			$wp_etag           = '"' . md5( $wp_last_modified ) . '"';509 510			$headers['Last-Modified'] = $wp_last_modified;511			$headers['ETag']          = $wp_etag;512 513			// Support for conditional GET.514			if ( isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) {

History

Introduced in 2.0.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.8.8 tag, from src/wp-includes/class-wp.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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