media_upload_form_handler(): null|array|void

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

null|array|void

Array of error messages keyed by attachment ID, null or void on success.

Performance profile

How much work a call to media_upload_form_handler() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via get_post().

Scaling

Scales with input

The body loops, so the work grows with how much data it finds.

Instructions

19–87

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 201.

Plugin surface

2 hooks

Third-party callbacks on 'attachment_fields_to_save', 'media_send_to_editor' run inside this call, and their cost is not bounded by anything here.

Called by

3

3 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• querycontent queryget_post()called directly
• hookthird-party callbacksapply_filters()called directly
• cacheobject cachewp_cache_delete()one call below media_upload_form_handler()
• optionoption read or writeget_option()one call below media_upload_form_handler()

Further down the call graph this can also reach serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 20 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost media_upload_form_handler() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 2

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

1. 1
   apply_filters( attachment_fields_to_save )filterline 792 (+51 into the body)

   Filters the attachment fields to be saved.

2. 2
   apply_filters( media_send_to_editor )filterline 858 (+117 into the body)

   Filters the HTML markup for a media item sent to the editor.

Uses · 16

• check_admin_referer()Ensures intent by verifying that a user was referred from another admin page with the correct security nonce.
• get_post()Retrieves post data given a post ID or post object.
• current_user_can()Returns whether the current user has the specified capability.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_unslash()Removes slashes from a string or recursively removes slashes from strings within an array.
• get_post_meta()Retrieves a post meta field for the given post ID.
• wp_strip_all_tags()Properly strips all HTML tags including 'script' and 'style'.
• update_post_meta()Updates a post meta field based on the given post ID.
• wp_slash()Adds slashes to a string or recursively adds slashes to strings within an array.
• wp_update_post()Updates a post with new post data.
• get_attachment_taxonomies()Retrieves taxonomies attached to given the attachment.
• wp_set_object_terms()Creates term and taxonomy relationships.

Used by · 3

• media_upload_gallery()Retrieves the legacy media uploader form in an iframe.
• media_upload_library()Retrieves the legacy media library form in an iframe.
• wp_media_upload_handler()Handles the process of uploading media.

Source code

View on Trac ↗View on GitHub ↗

741function media_upload_form_handler() {742	check_admin_referer( 'media-form' );743 744	$errors = null;745 746	if ( isset( $_POST['send'] ) ) {747		$keys    = array_keys( $_POST['send'] );748		$send_id = (int) reset( $keys );749	}750 751	if ( ! empty( $_POST['attachments'] ) ) {752		foreach ( $_POST['attachments'] as $attachment_id => $attachment ) {753			$post  = get_post( $attachment_id, ARRAY_A );754			$_post = $post;755 756			if ( ! current_user_can( 'edit_post', $attachment_id ) ) {757				continue;758			}759 760			if ( isset( $attachment['post_content'] ) ) {761				$post['post_content'] = $attachment['post_content'];762			}763 764			if ( isset( $attachment['post_title'] ) ) {765				$post['post_title'] = $attachment['post_title'];766			}767 768			if ( isset( $attachment['post_excerpt'] ) ) {769				$post['post_excerpt'] = $attachment['post_excerpt'];770			}771 772			if ( isset( $attachment['menu_order'] ) ) {773				$post['menu_order'] = $attachment['menu_order'];774			}775 776			if ( isset( $send_id ) && $attachment_id === $send_id ) {777				if ( isset( $attachment['post_parent'] ) ) {778					$post['post_parent'] = $attachment['post_parent'];779				}780			}781 782			/**783			 * Filters the attachment fields to be saved.784			 *785			 * @since 2.5.0786			 *787			 * @see wp_get_attachment_metadata()788			 *789			 * @param array $post       An array of post data.790			 * @param array $attachment An array of attachment metadata.791			 */792			$post = apply_filters( 'attachment_fields_to_save', $post, $attachment );793 794			if ( isset( $attachment['image_alt'] ) ) {795				$image_alt = wp_unslash( $attachment['image_alt'] );796 797				if ( get_post_meta( $attachment_id, '_wp_attachment_image_alt', true ) !== $image_alt ) {798					$image_alt = wp_strip_all_tags( $image_alt, true );799 800					// update_post_meta() expects slashed.801					update_post_meta( $attachment_id, '_wp_attachment_image_alt', wp_slash( $image_alt ) );802				}803			}804 805			if ( isset( $post['errors'] ) ) {806				$errors[ $attachment_id ] = $post['errors'];807				unset( $post['errors'] );808			}809 810			if ( $post != $_post ) {811				wp_update_post( $post );812			}813 814			foreach ( get_attachment_taxonomies( $post ) as $t ) {815				if ( isset( $attachment[ $t ] ) ) {816					wp_set_object_terms( $attachment_id, array_map( 'trim', preg_split( '/,+/', $attachment[ $t ] ) ), $t, false );817				}818			}819		}820	}

Changelog

Introduced in 2.5.0. One change between 6.7.7 and 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-admin/includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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