WP_REST_Attachments_Controller::prepare_item_for_response( WP_Post $item, WP_REST_Request $request ): WP_REST_Response

Compatibility

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

Parameters

$itemWP_Post

Attachment object.

$requestWP_REST_Request

Request object.

Return value

WP_REST_Response

Response object.

Performance profile

How much work a call to WP_REST_Attachments_Controller::prepare_item_for_response() 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 what you pass in.

Instructions

67–163

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 239.

Plugin surface

4 hooks

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

Called by

4

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

What it touches

• hookthird-party callbacksapply_filters()called directly
• querycontent queryget_post()one call below WP_REST_Attachments_Controller::prepare_item_for_response()

Further down the call graph this can also reach cache, option, 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 · 80 distinct outcomes

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

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Hooks and filters fired · 4

4 hooks fire while WP_REST_Attachments_Controller::prepare_item_for_response() runs, in this order:

1. 1
   apply_filters( the_content )filterline 862 (+12 into the body)

   Filters the post content.

2. 2
   apply_filters( get_the_excerpt )filterline 868 (+18 into the body)

   Filters the retrieved post excerpt.

3. 3
   apply_filters( the_excerpt )filterline 871 (+21 into the body)

   Filters the displayed post excerpt.

4. 4
   apply_filters( rest_prepare_attachment )filterline 970 (+120 into the body)

   Filters an attachment returned from the REST API.

Uses · 13

• apply_filters()Calls the callback functions that have been added to a filter hook.
• get_post_meta()Retrieves a post meta field for the given post ID.
• wp_attachment_is_image()Determines whether an attachment is an image.
• wp_get_attachment_metadata()Retrieves attachment metadata for attachment ID.
• wp_get_attachment_image_src()Retrieves an image to represent an attachment.
• wp_basename()i18n-friendly version of basename().
• wp_get_attachment_url()Retrieves the URL for an attachment.
• wp_get_missing_image_subsizes()Compare the existing image sub-sizes (as saved in the attachment meta) to the currently registered image sub-sizes, and return the difference.
• rest_ensure_response()Ensures a REST response is a response object (for consistency).
• WP_REST_Posts_Controller::prepare_item_for_response()Prepares a single post output for response.
• WP_REST_Attachments_Controller::get_fields_for_response()
• stdClass::__construct()

Used by · 4

• WP_REST_Attachments_Controller::create_item()Creates a single attachment.
• WP_REST_Attachments_Controller::edit_media_item()Applies edits to a media item and creates a new attachment record.
• WP_REST_Attachments_Controller::post_process_item()Performs post-processing on an attachment.
• WP_REST_Attachments_Controller::update_item()Updates a single attachment.

Source code

View on Trac ↗View on GitHub ↗

850	public function prepare_item_for_response( $item, $request ) {851		// Restores the more descriptive, specific name for use within this method.852		$post = $item;853 854		$response = parent::prepare_item_for_response( $post, $request );855		$fields   = $this->get_fields_for_response( $request );856		$data     = $response->get_data();857 858		if ( in_array( 'description', $fields, true ) ) {859			$data['description'] = array(860				'raw'      => $post->post_content,861				/** This filter is documented in wp-includes/post-template.php */862				'rendered' => apply_filters( 'the_content', $post->post_content ),863			);864		}865 866		if ( in_array( 'caption', $fields, true ) ) {867			/** This filter is documented in wp-includes/post-template.php */868			$caption = apply_filters( 'get_the_excerpt', $post->post_excerpt, $post );869 870			/** This filter is documented in wp-includes/post-template.php */871			$caption = apply_filters( 'the_excerpt', $caption );872 873			$data['caption'] = array(874				'raw'      => $post->post_excerpt,875				'rendered' => $caption,876			);877		}878 879		if ( in_array( 'alt_text', $fields, true ) ) {880			$data['alt_text'] = get_post_meta( $post->ID, '_wp_attachment_image_alt', true );881		}882 883		if ( in_array( 'media_type', $fields, true ) ) {884			$data['media_type'] = wp_attachment_is_image( $post->ID ) ? 'image' : 'file';885		}886 887		if ( in_array( 'mime_type', $fields, true ) ) {888			$data['mime_type'] = $post->post_mime_type;889		}890 891		if ( in_array( 'media_details', $fields, true ) ) {892			$data['media_details'] = wp_get_attachment_metadata( $post->ID );893 894			// Ensure empty details is an empty object.895			if ( empty( $data['media_details'] ) ) {896				$data['media_details'] = new stdClass();897			} elseif ( ! empty( $data['media_details']['sizes'] ) ) {898 899				foreach ( $data['media_details']['sizes'] as $size => &$size_data ) {900 901					if ( isset( $size_data['mime-type'] ) ) {902						$size_data['mime_type'] = $size_data['mime-type'];903						unset( $size_data['mime-type'] );904					}905 906					// Use the same method image_downsize() does.907					$image_src = wp_get_attachment_image_src( $post->ID, $size );908					if ( ! $image_src ) {909						continue;910					}911 912					$size_data['source_url'] = $image_src[0];913				}914 915				$full_src = wp_get_attachment_image_src( $post->ID, 'full' );916 917				if ( ! empty( $full_src ) ) {918					$data['media_details']['sizes']['full'] = array(919						'file'       => wp_basename( $full_src[0] ),920						'width'      => $full_src[1],921						'height'     => $full_src[2],922						'mime_type'  => $post->post_mime_type,923						'source_url' => $full_src[0],924					);925				}926			} else {927				$data['media_details']['sizes'] = new stdClass();928			}929		}

Changelog

Introduced in 4.7.0. 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/rest-api/endpoints/class-wp-rest-attachments-controller.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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