/** * REST API: WP_REST_Attachments_Controller class * * @package WordPress * @subpackage REST_API * @since 4.7.0 */ /** * Core controller used to access attachments via the REST API. * * @since 4.7.0 * * @see WP_REST_Posts_Controller */ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller { /** * Whether the controller supports batching. * * @since 5.9.0 * @var false */ protected $allow_batch = false; /** * Registers the routes for attachments. * * @since 5.3.0 * * @see register_rest_route() */ public function register_routes() { parent::register_routes(); register_rest_route( $this->namespace, '/' . $this->rest_base . '/(?P[\d]+)/post-process', array( 'methods' => WP_REST_Server::CREATABLE, 'callback' => array( $this, 'post_process_item' ), 'permission_callback' => array( $this, 'post_process_item_permissions_check' ), 'args' => array( 'id' => array( 'description' => __( 'Unique identifier for the attachment.' ), 'type' => 'integer', ), 'action' => array( 'type' => 'string', 'enum' => array( 'create-image-subsizes' ), 'required' => true, ), ), ) ); register_rest_route( $this->namespace, '/' . $this->rest_base . '/(?P[\d]+)/edit', array( 'methods' => WP_REST_Server::CREATABLE, 'callback' => array( $this, 'edit_media_item' ), 'permission_callback' => array( $this, 'edit_media_item_permissions_check' ), 'args' => $this->get_edit_media_item_args(), ) ); } /** * Determines the allowed query_vars for a get_items() response and * prepares for WP_Query. * * @since 4.7.0 * * @param array $prepared_args Optional. Array of prepared arguments. Default empty array. * @param WP_REST_Request $request Optional. Request to prepare items for. * @return array Array of query arguments. */ protected function prepare_items_query( $prepared_args = array(), $request = null ) { $query_args = parent::prepare_items_query( $prepared_args, $request ); if ( empty( $query_args['post_status'] ) ) { $query_args['post_status'] = 'inherit'; } $media_types = $this->get_media_types(); if ( ! empty( $request['media_type'] ) && isset( $media_types[ $request['media_type'] ] ) ) { $query_args['post_mime_type'] = $media_types[ $request['media_type'] ]; } if ( ! empty( $request['mime_type'] ) ) { $parts = explode( '/', $request['mime_type'] ); if ( isset( $media_types[ $parts[0] ] ) && in_array( $request['mime_type'], $media_types[ $parts[0] ], true ) ) { $query_args['post_mime_type'] = $request['mime_type']; } } // Filter query clauses to include filenames. if ( isset( $query_args['s'] ) ) { add_filter( 'wp_allow_query_attachment_by_filename', '__return_true' ); } return $query_args; } /** * Checks if a given request has access to create an attachment. * * @since 4.7.0 * * @param WP_REST_Request $request Full details about the request. * @return true|WP_Error Boolean true if the attachment may be created, or a WP_Error if not. */ public function create_item_permissions_check( $request ) { $ret = parent::create_item_permissions_check( $request ); if ( ! $ret || is_wp_error( $ret ) ) { return $ret; } if ( ! current_user_can( 'upload_files' ) ) { return new WP_Error( 'rest_cannot_create', __( 'Sorry, you are not allowed to upload media on this site.' ), array( 'status' => 400 ) ); } // Attaching media to a post requires ability to edit said post. if ( ! empty( $request['post'] ) && ! current_user_can( 'edit_post', (int) $request['post'] ) ) { return new WP_Error( 'rest_cannot_edit', __( 'Sorry, you are not allowed to upload media to this post.' ), array( 'status' => rest_authorization_required_code() ) ); } $files = $request->get_file_params(); /** * Filter whether the server should prevent uploads for image types it doesn't support. Default true. * * Developers can use this filter to enable uploads of certain image types. By default image types that are not * supported by the server are prevented from being uploaded. * * @since 6.8.0 * * @param bool $check_mime Whether to prevent uploads of unsupported image types. * @param string|null $mime_type The mime type of the file being uploaded (if available). */ $prevent_unsupported_uploads = apply_filters( 'wp_prevent_unsupported_mime_type_uploads', true, isset( $files['file']['type'] ) ? $files['file']['type'] : null ); // If the upload is an image, check if the server can handle the mime type. if ( $prevent_unsupported_uploads && isset( $files['file']['type'] ) && str_starts_with( $files['file']['type'], 'image/' ) ) { // List of non-resizable image formats. $editor_non_resizable_formats = array( 'image/svg+xml', ); // Check if the image editor supports the type or ignore if it isn't a format resizable by an editor. if ( ! in_array( $files['file']['type'], $editor_non_resizable_formats, true ) && ! wp_image_editor_supports( array( 'mime_type' => $files['file']['type'] ) ) ) { return new WP_Error( 'rest_upload_image_type_not_supported', __( 'The web server cannot generate responsive image sizes for this image. Convert it to JPEG or PNG before uploading.' ), array( 'status' => 400 ) ); } } return true; } /** * Creates a single attachment. * * @since 4.7.0 * * @param WP_REST_Request $request Full details about the request. * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure. */ public function create_item( $request ) { if ( ! empty( $request['post'] ) && in_array( get_post_type( $request['post'] ), array( 'revision', 'attachment' ), true ) ) { return new WP_Error( 'rest_invalid_param', __( 'Invalid parent type.' ), array( 'status' => 400 ) ); } $insert = $this->insert_attachment( $request ); if ( is_wp_error( $insert ) ) { return $insert; } $schema = $this->get_item_schema(); // Extract by name. $attachment_id = $insert['attachment_id']; $file = $insert['file']; if ( isset( $request['alt_text'] ) ) { update_post_meta( $attachment_id, '_wp_attachment_image_alt', sanitize_text_field( $request['alt_text'] ) ); } if ( ! empty( $schema['properties']['featured_media'] ) && isset( $request['featured_media'] ) ) { $thumbnail_update = $this->handle_featured_media( $request['featured_media'], $attachment_id ); if ( is_wp_error( $thumbnail_update ) ) { return $thumbnail_update; } } if ( ! empty( $schema['properties']['meta'] ) && isset( $request['meta'] ) ) { $meta_update = $this->meta->update_value( $request['meta'], $attachment_id ); if ( is_wp_error( $meta_update ) ) { return $meta_update; } } $attachment = get_post( $attachment_id ); $fields_update = $this->update_additional_fields_for_object( $attachment, $request ); if ( is_wp_error( $fields_update ) ) { return $fields_update; } $terms_update = $this->handle_terms( $attachment_id, $request ); if ( is_wp_error( $terms_update ) ) { return $terms_update; } $request->set_param( 'context', 'edit' ); /** * Fires after a single attachment is completely created or updated via the REST API. * * @since 5.0.0 * * @param WP_Post $attachment Inserted or updated attachment object. * @param WP_REST_Request $request Request object. * @param bool $creating True when creating an attachment, false when updating. */ do_action( 'rest_after_insert_attachment', $attachment, $request, true ); wp_after_insert_post( $attachment, false, null ); if ( wp_is_serving_rest_request() ) { /* * Set a custom header with the attachment_id. * Used by the browser/client to resume creating image sub-sizes after a PHP fatal error. */ header( 'X-WP-Upload-Attachment-ID: ' . $attachment_id ); } // Include media and image functions to get access to wp_generate_attachment_metadata(). require_once ABSPATH . 'wp-admin/includes/media.php'; require_once ABSPATH . 'wp-admin/includes/image.php'; /* * Post-process the upload (create image sub-sizes, make PDF thumbnails, etc.) and insert attachment meta. * At this point the server may run out of resources and post-processing of uploaded images may fail. */ wp_update_attachment_metadata( $attachment_id, wp_generate_attachment_metadata( $attachment_id, $file ) ); $response = $this->prepare_item_for_response( $attachment, $request ); $response = rest_ensure_response( $response ); $response->set_status( 201 ); $response->header( 'Location', rest_url( sprintf( '%s/%s/%d', $this->namespace, $this->rest_base, $attachment_id ) ) ); return $response; } /** * Inserts the attachment post in the database. Does not update the attachment meta. * * @since 5.3.0 * * @param WP_REST_Request $request * @return array|WP_Error */ protected function insert_attachment( $request ) { // Get the file via $_FILES or raw data. $files = $request->get_file_params(); $headers = $request->get_headers(); $time = null; // Matches logic in media_handle_upload(). if ( ! empty( $request['post'] ) ) { $post = get_post( $request['post'] ); // The post date doesn't usually matter for pages, so don't backdate this upload. if ( $post && 'page' !== $post->post_type && substr( $post->post_date, 0, 4 ) > 0 ) { $time = $post->post_date; } } if ( ! empty( $files ) ) { $file = $this->upload_from_file( $files, $headers, $time ); } else { $file = $this->upload_from_data( $request->get_body(), $headers, $time ); } if ( is_wp_error( $file ) ) { return $file; } $name = wp_basename( $file['file'] ); $name_parts = pathinfo( $name ); $name = trim( substr( $name, 0, -( 1 + strlen( $name_parts['extension'] ) ) ) ); $url = $file['url']; $type = $file['type']; $file = $file['file']; // Include image functions to get access to wp_read_image_metadata(). require_once ABSPATH . 'wp-admin/includes/image.php'; // Use image exif/iptc data for title and caption defaults if possible. $image_meta = wp_read_image_metadata( $file ); if ( ! empty( $image_meta ) ) { if ( empty( $request['title'] ) && trim( $image_meta['title'] ) && ! is_numeric( sanitize_title( $image_meta['title'] ) ) ) { $request['title'] = $image_meta['title']; } if ( empty( $request['caption'] ) && trim( $image_meta['caption'] ) ) { $request['caption'] = $image_meta['caption']; } } $attachment = $this->prepare_item_for_database( $request ); $attachment->post_mime_type = $type; $attachment->guid = $url; // If the title was not set, use the original filename. if ( empty( $attachment->post_title ) && ! empty( $files['file']['name'] ) ) { // Remove the file extension (after the last `.`) $tmp_title = substr( $files['file']['name'], 0, strrpos( $files['file']['name'], '.' ) ); if ( ! empty( $tmp_title ) ) { $attachment->post_title = $tmp_title; } } // Fall back to the original approach. if ( empty( $attachment->post_title ) ) { $attachment->post_title = preg_replace( '/\.[^.]+$/', '', wp_basename( $file ) ); } // $post_parent is inherited from $attachment['post_parent']. $id = wp_insert_attachment( wp_slash( (array) $attachment ), $file, 0, true, false ); if ( is_wp_error( $id ) ) { if ( 'db_update_error' === $id->get_error_code() ) { $id->add_data( array( 'status' => 500 ) ); } else { $id->add_data( array( 'status' => 400 ) ); } return $id; } $attachment = get_post( $id ); /** * Fires after a single attachment is created or updated via the REST API. * * @since 4.7.0 * * @param WP_Post $attachment Inserted or updated attachment object. * @param WP_REST_Request $request The request sent to the API. * @param bool $creating True when creating an attachment, false when updating. */ do_action( 'rest_insert_attachment', $attachment, $request, true ); return array( 'attachment_id' => $id, 'file' => $file, ); } /** * Determines the featured media based on a request param. * * @since 6.5.0 * * @param int $featured_media Featured Media ID. * @param int $post_id Post ID. * @return bool|WP_Error Whether the post thumbnail was successfully deleted, otherwise WP_Error. */ protected function handle_featured_media( $featured_media, $post_id ) { $post_type = get_post_type( $post_id ); $thumbnail_support = current_theme_supports( 'post-thumbnails', $post_type ) && post_type_supports( $post_type, 'thumbnail' ); // Similar check as in wp_insert_post(). if ( ! $thumbnail_support && get_post_mime_type( $post_id ) ) { if ( wp_attachment_is( 'audio', $post_id ) ) { $thumbnail_support = post_type_supports( 'attachment:audio', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:audio' ); } elseif ( wp_attachment_is( 'video', $post_id ) ) { $thumbnail_support = post_type_supports( 'attachment:video', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:video' ); } } if ( $thumbnail_support ) { return parent::handle_featured_media( $featured_media, $post_id ); } return new WP_Error( 'rest_no_featured_media', sprintf( /* translators: %s: attachment mime type */ __( 'This site does not support post thumbnails on attachments with MIME type %s.' ), get_post_mime_type( $post_id ) ), array( 'status' => 400 ) ); } /** * Updates a single attachment. * * @since 4.7.0 * * @param WP_REST_Request $request Full details about the request. * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure. */ public function update_item( $request ) { if ( ! empty( $request['post'] ) && in_array( get_post_type( $request['post'] ), array( 'revision', 'attachment' ), true ) ) { return new WP_Error( 'rest_invalid_param', __( 'Invalid parent type.' ), array( 'status' => 400 ) ); } $attachment_before = get_post( $request['id'] ); $response = parent::update_item( $request ); if ( is_wp_error( $response ) ) { return $response; } $response = rest_ensure_response( $response ); $data = $response->get_data(); if ( isset( $request['alt_text'] ) ) { update_post_meta( $data['id'], '_wp_attachment_image_alt', $request['alt_text'] ); } $attachment = get_post( $request['id'] ); if ( ! empty( $schema['properties']['featured_media'] ) && isset( $request['featured_media'] ) ) { $thumbnail_update = $this->handle_featured_media( $request['featured_media'], $attachment->ID ); if ( is_wp_error( $thumbnail_update ) ) { return $thumbnail_update; } } $fields_update = $this->update_additional_fields_for_object( $attachment, $request ); if ( is_wp_error( $fields_update ) ) { return $fields_update; } $request->set_param( 'context', 'edit' ); /** This action is documented in wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php */ do_action( 'rest_after_insert_attachment', $attachment, $request, false ); wp_after_insert_post( $attachment, true, $attachment_before ); $response = $this->prepare_item_for_response( $attachment, $request ); $response = rest_ensure_response( $response ); return $response; } /** * Performs post-processing on an attachment. * * @since 5.3.0 * * @param WP_REST_Request $request Full details about the request. * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure. */ public function post_process_item( $request ) { switch ( $request['action'] ) { case 'create-image-subsizes': require_once ABSPATH . 'wp-admin/includes/image.php'; wp_update_image_subsizes( $request['id'] ); break; } $request['context'] = 'edit'; return $this->prepare_item_for_response( get_post( $request['id'] ), $request ); } /** * Checks if a given request can perform post-processing on an attachment. * * @since 5.3.0 * * @param WP_REST_Request $request Full details about the request. * @return true|WP_Error True if the request has access to update the item, WP_Error object otherwise. */ public function post_process_item_permissions_check( $request ) { return $this->update_item_permissions_check( $request ); } /** * Checks if a given request has access to editing media. * * @since 5.5.0 * * @param WP_REST_Request $request Full details about the request. * @return true|WP_Error True if the request has read access, WP_Error object otherwise. */ public function edit_media_item_permissions_check( $request ) { if ( ! current_user_can( 'upload_files' ) ) { return new WP_Error( 'rest_cannot_edit_image', __( 'Sorry, you are not allowed to upload media on this site.' ), array( 'status' => rest_authorization_required_code() ) ); } return $this->update_item_permissions_check( $request ); } /** * Applies edits to a media item and creates a new attachment record. * * @since 5.5.0 * * @param WP_REST_Request $request Full details about the request. * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure. */ public function edit_media_item( $request ) { require_once ABSPATH . 'wp-admin/includes/image.php'; $attachment_id = $request['id']; // This also confirms the attachment is an image. $image_file = wp_get_original_image_path( $attachment_id ); $image_meta = wp_get_attachment_metadata( $attachment_id ); if ( ! $image_meta || ! $image_file || ! wp_image_file_matches_image_meta( $request['src'], $image_meta, $attachment_id ) ) { return new WP_Error( 'rest_unknown_attachment', __( 'Unable to get meta information for file.' ), array( 'status' => 404 ) ); } $supported_types = array( 'image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/avif', 'image/heic' ); $mime_type = get_post_mime_type( $attachment_id ); if ( ! in_array( $mime_type, $supported_types, true ) ) { return new WP_Error( 'rest_cannot_edit_file_type', __( 'This type of file cannot be edited.' ), array( 'status' => 400 ) ); } // The `modifiers` param takes precedence over the older format. if ( isset( $request['modifiers'] ) ) { $modifiers = $request['modifiers']; } else { $modifiers = array(); if ( ! empty( $request['rotation'] ) ) { $modifiers[] = array( 'type' => 'rotate', 'args' => array( 'angle' => $request['rotation'], ), ); } if ( isset( $request['x'], $request['y'], $request['width'], $request['height'] ) ) { $modifiers[] = array( 'type' => 'crop', 'args' => array( 'left' => $request['x'], 'top' => $request['y'], 'width' => $request['width'], 'height' => $request['height'], ), ); } if ( 0 === count( $modifiers ) ) { return new WP_Error( 'rest_image_not_edited', __( 'The image was not edited. Edit the image before applying the changes.' ), array( 'status' => 400 ) ); } } /* * If the file doesn't exist, attempt a URL fopen on the src link. * This can occur with certain file replication plugins. * Keep the original file path to get a modified name later. */ $image_file_to_edit = $image_file; if ( ! file_exists( $image_file_to_edit ) ) { $image_file_to_edit = _load_image_to_edit_path( $attachment_id ); } $image_editor = wp_get_image_editor( $image_file_to_edit ); if ( is_wp_error( $image_editor ) ) { return new WP_Error( 'rest_unknown_image_file_type', __( 'Unable to edit this image.' ), array( 'status' => 500 ) ); } foreach ( $modifiers as $modifier ) { $args = $modifier['args']; switch ( $modifier['type'] ) { case 'rotate': // Rotation direction: clockwise vs. counterclockwise. $rotate = 0 - $args['angle']; if ( 0 !== $rotate ) { $result = $image_editor->rotate( $rotate ); if ( is_wp_error( $result ) ) { return new WP_Error( 'rest_image_rotation_failed', __( 'Unable to rotate this image.' ), array( 'status' => 500 ) ); } } break; case 'crop': $size = $image_editor->get_size(); $crop_x = (int) round( ( $size['width'] * $args['left'] ) / 100.0 ); $crop_y = (int) round( ( $size['height'] * $args['top'] ) / 100.0 ); $width = (int) round( ( $size['width'] * $args['width'] ) / 100.0 ); $height = (int) round( ( $size['height'] * $args['height'] ) / 100.0 ); if ( $size['width'] !== $width || $size['height'] !== $height ) { $result = $image_editor->crop( $crop_x, $crop_y, $width, $height ); if ( is_wp_error( $result ) ) { return new WP_Error( 'rest_image_crop_failed', __( 'Unable to crop this image.' ), array( 'status' => 500 ) ); } } break; } } // Calculate the file name. $image_ext = pathinfo( $image_file, PATHINFO_EXTENSION ); $image_name = wp_basename( $image_file, ".{$image_ext}" ); /* * Do not append multiple `-edited` to the file name. * The user may be editing a previously edited image. */ if ( preg_match( '/-edited(-\d+)?$/', $image_name ) ) { // Remove any `-1`, `-2`, etc. `wp_unique_filename()` will add the proper number. $image_name = preg_replace( '/-edited(-\d+)?$/', '-edited', $image_name ); } else { // Append `-edited` before the extension. $image_name .= '-edited'; } $filename = "{$image_name}.{$image_ext}"; // Create the uploads subdirectory if needed. $uploads = wp_upload_dir(); // Make the file name unique in the (new) upload directory. $filename = wp_unique_filename( $uploads['path'], $filename ); // Save to disk. $saved = $image_editor->save( $uploads['path'] . "/$filename" ); if ( is_wp_error( $saved ) ) { return $saved; } // Create new attachment post. $new_attachment_post = array( 'post_mime_type' => $saved['mime-type'], 'guid' => $uploads['url'] . "/$filename", 'post_title' => $image_name, 'post_content' => '', ); // Copy post_content, post_excerpt, and post_title from the edited image's attachment post. $attachment_post = get_post( $attachment_id ); if ( $attachment_post ) { $new_attachment_post['post_content'] = $attachment_post->post_content; $new_attachment_post['post_excerpt'] = $attachment_post->post_excerpt; $new_attachment_post['post_title'] = $attachment_post->post_title; } $new_attachment_id = wp_insert_attachment( wp_slash( $new_attachment_post ), $saved['path'], 0, true ); if ( is_wp_error( $new_attachment_id ) ) { if ( 'db_update_error' === $new_attachment_id->get_error_code() ) { $new_attachment_id->add_data( array( 'status' => 500 ) ); } else { $new_attachment_id->add_data( array( 'status' => 400 ) ); } return $new_attachment_id; } // Copy the image alt text from the edited image. $image_alt = get_post_meta( $attachment_id, '_wp_attachment_image_alt', true ); if ( ! empty( $image_alt ) ) { // update_post_meta() expects slashed. update_post_meta( $new_attachment_id, '_wp_attachment_image_alt', wp_slash( $image_alt ) ); } if ( wp_is_serving_rest_request() ) { /* * Set a custom header with the attachment_id. * Used by the browser/client to resume creating image sub-sizes after a PHP fatal error. */ header( 'X-WP-Upload-Attachment-ID: ' . $new_attachment_id ); } // Generate image sub-sizes and meta. $new_image_meta = wp_generate_attachment_metadata( $new_attachment_id, $saved['path'] ); // Copy the EXIF metadata from the original attachment if not generated for the edited image. if ( isset( $image_meta['image_meta'] ) && isset( $new_image_meta['image_meta'] ) && is_array( $new_image_meta['image_meta'] ) ) { // Merge but skip empty values. foreach ( (array) $image_meta['image_meta'] as $key => $value ) { if ( empty( $new_image_meta['image_meta'][ $key ] ) && ! empty( $value ) ) { $new_image_meta['image_meta'][ $key ] = $value; } } } // Reset orientation. At this point the image is edited and orientation is correct. if ( ! empty( $new_image_meta['image_meta']['orientation'] ) ) { $new_image_meta['image_meta']['orientation'] = 1; } // The attachment_id may change if the site is exported and imported. $new_image_meta['parent_image'] = array( 'attachment_id' => $attachment_id, // Path to the originally uploaded image file relative to the uploads directory. 'file' => _wp_relative_upload_path( $image_file ), ); /** * Filters the meta data for the new image created by editing an existing image. * * @since 5.5.0 * * @param array $new_image_meta Meta data for the new image. * @param int $new_attachment_id Attachment post ID for the new image. * @param int $attachment_id Attachment post ID for the edited (parent) image. */ $new_image_meta = apply_filters( 'wp_edited_image_metadata', $new_image_meta, $new_attachment_id, $attachment_id ); wp_update_attachment_metadata( $new_attachment_id, $new_image_meta ); $response = $this->prepare_item_for_response( get_post( $new_attachment_id ), $request ); $response->set_status( 201 ); $response->header( 'Location', rest_url( sprintf( '%s/%s/%s', $this->namespace, $this->rest_base, $new_attachment_id ) ) ); return $response; } /** * Prepares a single attachment for create or update. * * @since 4.7.0 * * @param WP_REST_Request $request Request object. * @return stdClass|WP_Error Post object. */ protected function prepare_item_for_database( $request ) { $prepared_attachment = parent::prepare_item_for_database( $request ); // Attachment caption (post_excerpt internally). if ( isset( $request['caption'] ) ) { if ( is_string( $request['caption'] ) ) { $prepared_attachment->post_excerpt = $request['caption']; } elseif ( isset( $request['caption']['raw'] ) ) { $prepared_attachment->post_excerpt = $request['caption']['raw']; } } // Attachment description (post_content internally). if ( isset( $request['description'] ) ) { if ( is_string( $request['description'] ) ) { $prepared_attachment->post_content = $request['description']; } elseif ( isset( $request['description']['raw'] ) ) { $prepared_attachment->post_content = $request['description']['raw']; } } if ( isset( $request['post'] ) ) { $prepared_attachment->post_parent = (int) $request['post']; } return $prepared_attachment; } /** * Prepares a single attachment output for response. * * @since 4.7.0 * @since 5.9.0 Renamed `$post` to `$item` to match parent class for PHP 8 named parameter support. * * @param WP_Post $item Attachment object. * @param WP_REST_Request $request Request object. * @return WP_REST_Response Response object. */ public function prepare_item_for_response( $item, $request ) { // Restores the more descriptive, specific name for use within this method. $post = $item; $response = parent::prepare_item_for_response( $post, $request ); $fields = $this->get_fields_for_response( $request ); $data = $response->get_data(); if ( in_array( 'description', $fields, true ) ) { $data['description'] = array( 'raw' => $post->post_content, /** This filter is documented in wp-includes/post-template.php */ 'rendered' => apply_filters( 'the_content', $post->post_content ), ); } if ( in_array( 'caption', $fields, true ) ) { /** This filter is documented in wp-includes/post-template.php */ $caption = apply_filters( 'get_the_excerpt', $post->post_excerpt, $post ); /** This filter is documented in wp-includes/post-template.php */ $caption = apply_filters( 'the_excerpt', $caption ); $data['caption'] = array( 'raw' => $post->post_excerpt, 'rendered' => $caption, ); } if ( in_array( 'alt_text', $fields, true ) ) { $data['alt_text'] = get_post_meta( $post->ID, '_wp_attachment_image_alt', true ); } if ( in_array( 'media_type', $fields, true ) ) { $data['media_type'] = wp_attachment_is_image( $post->ID ) ? 'image' : 'file'; } if ( in_array( 'mime_type', $fields, true ) ) { $data['mime_type'] = $post->post_mime_type; } if ( in_array( 'media_details', $fields, true ) ) { $data['media_details'] = wp_get_attachment_metadata( $post->ID ); // Ensure empty details is an empty object. if ( empty( $data['media_details'] ) ) { $data['media_details'] = new stdClass(); } elseif ( ! empty( $data['media_details']['sizes'] ) ) { foreach ( $data['media_details']['sizes'] as $size => &$size_data ) { if ( isset( $size_data['mime-type'] ) ) { $size_data['mime_type'] = $size_data['mime-type']; unset( $size_data['mime-type'] ); } // Use the same method image_downsize() does. $image_src = wp_get_attachment_image_src( $post->ID, $size ); if ( ! $image_src ) { continue; } $size_data['source_url'] = $image_src[0]; } $full_src = wp_get_attachment_image_src( $post->ID, 'full' ); if ( ! empty( $full_src ) ) { $data['media_details']['sizes']['full'] = array( 'file' => wp_basename( $full_src[0] ), 'width' => $full_src[1], 'height' => $full_src[2], 'mime_type' => $post->post_mime_type, 'source_url' => $full_src[0], ); } } else { $data['media_details']['sizes'] = new stdClass(); } } if ( in_array( 'post', $fields, true ) ) { $data['post'] = ! empty( $post->post_parent ) ? (int) $post->post_parent : null; } if ( in_array( 'source_url', $fields, true ) ) { $data['source_url'] = wp_get_attachment_url( $post->ID ); } if ( in_array( 'missing_image_sizes', $fields, true ) ) { require_once ABSPATH . 'wp-admin/includes/image.php'; $data['missing_image_sizes'] = array_keys( wp_get_missing_image_subsizes( $post->ID ) ); } $context = ! empty( $request['context'] ) ? $request['context'] : 'view'; $data = $this->filter_response_by_context( $data, $context ); $links = $response->get_links(); // Wrap the data in a response object. $response = rest_ensure_response( $data ); foreach ( $links as $rel => $rel_links ) { foreach ( $rel_links as $link ) { $response->add_link( $rel, $link['href'], $link['attributes'] ); } } /** * Filters an attachment returned from the REST API. * * Allows modification of the attachment right before it is returned. * * @since 4.7.0 * * @param WP_REST_Response $response The response object. * @param WP_Post $post The original attachment post. * @param WP_REST_Request $request Request used to generate the response. */ return apply_filters( 'rest_prepare_attachment', $response, $post, $request ); } /** * Retrieves the attachment's schema, conforming to JSON Schema. * * @since 4.7.0 * * @return array Item schema as an array. */ public function get_item_schema() { if ( $this->schema ) { return $this->add_additional_fields_schema( $this->schema ); } $schema = parent::get_item_schema(); $schema['properties']['alt_text'] = array( 'description' => __( 'Alternative text to display when attachment is not displayed.' ), 'type' => 'string', 'context' => array( 'view', 'edit', 'embed' ), 'arg_options' => array( 'sanitize_callback' => 'sanitize_text_field', ), ); $schema['properties']['caption'] = array( 'description' => __( 'The attachment caption.' ), 'type' => 'object', 'context' => array( 'view', 'edit', 'embed' ), 'arg_options' => array( 'sanitize_callback' => null, // Note: sanitization implemented in self::prepare_item_for_database(). 'validate_callback' => null, // Note: validation implemented in self::prepare_item_for_database(). ), 'properties' => array( 'raw' => array( 'description' => __( 'Caption for the attachment, as it exists in the database.' ), 'type' => 'string', 'context' => array( 'edit' ), ), 'rendered' => array( 'description' => __( 'HTML caption for the attachment, transformed for display.' ), 'type' => 'string', 'context' => array( 'view', 'edit', 'embed' ), 'readonly' => true, ), ), ); $schema['properties']['description'] = array( 'description' => __( 'The attachment description.' ), 'type' => 'object', 'context' => array( 'view', 'edit' ), 'arg_options' => array( 'sanitize_callback' => null, // Note: sanitization implemented in self::prepare_item_for_database(). 'validate_callback' => null, // Note: validation implemented in self::prepare_item_for_database(). ), 'properties' => array( 'raw' => array( 'description' => __( 'Description for the attachment, as it exists in the database.' ), 'type' => 'string', 'context' => array( 'edit' ), ), 'rendered' => array( 'description' => __( 'HTML description for the attachment, transformed for display.' ), 'type' => 'string', 'context' => array( 'view', 'edit' ), 'readonly' => true, ), ), ); $schema['properties']['media_type'] = array( 'description' => __( 'Attachment type.' ), 'type' => 'string', 'enum' => array( 'image', 'file' ), 'context' => array( 'view', 'edit', 'embed' ), 'readonly' => true, ); $schema['properties']['mime_type'] = array( 'description' => __( 'The attachment MIME type.' ), 'type' => 'string', 'context' => array( 'view', 'edit', 'embed' ), 'readonly' => true, ); $schema['properties']['media_details'] = array( 'description' => __( 'Details about the media file, specific to its type.' ), 'type' => 'object', 'context' => array( 'view', 'edit', 'embed' ), 'readonly' => true, ); $schema['properties']['post'] = array( 'description' => __( 'The ID for the associated post of the attachment.' ), 'type' => 'integer', 'context' => array( 'view', 'edit' ), ); $schema['properties']['source_url'] = array( 'description' => __( 'URL to the original attachment file.' ), 'type' => 'string', 'format' => 'uri', 'context' => array( 'view', 'edit', 'embed' ), 'readonly' => true, ); $schema['properties']['missing_image_sizes'] = array( 'description' => __( 'List of the missing image sizes of the attachment.' ), 'type' => 'array', 'items' => array( 'type' => 'string' ), 'context' => array( 'edit' ), 'readonly' => true, ); unset( $schema['properties']['password'] ); $this->schema = $schema; return $this->add_additional_fields_schema( $this->schema ); } /** * Handles an upload via raw POST data. * * @since 4.7.0 * @since 6.6.0 Added the `$time` parameter. * * @param string $data Supplied file data. * @param array $headers HTTP headers from the request. * @param string|null $time Optional. Time formatted in 'yyyy/mm'. Default null. * @return array|WP_Error Data from wp_handle_sideload(). */ protected function upload_from_data( $data, $headers, $time = null ) { if ( empty( $data ) ) { return new WP_Error( 'rest_upload_no_data', __( 'No data supplied.' ), array( 'status' => 400 ) ); } if ( empty( $headers['content_type'] ) ) { return new WP_Error( 'rest_upload_no_content_type', __( 'No Content-Type supplied.' ), array( 'status' => 400 ) ); } if ( empty( $headers['content_disposition'] ) ) { return new WP_Error( 'rest_upload_no_content_disposition', __( 'No Content-Disposition supplied.' ), array( 'status' => 400 ) ); } $filename = self::get_filename_from_disposition( $headers['content_disposition'] ); if ( empty( $filename ) ) { return new WP_Error( 'rest_upload_invalid_disposition', __( 'Invalid Content-Disposition supplied. Content-Disposition needs to be formatted as `attachment; filename="image.png"` or similar.' ), array( 'status' => 400 ) ); } if ( ! empty( $headers['content_md5'] ) ) { $content_md5 = array_shift( $headers['content_md5'] ); $expected = trim( $content_md5 ); $actual = md5( $data ); if ( $expected !== $actual ) { return new WP_Error( 'rest_upload_hash_mismatch', __( 'Content hash did not match expected.' ), array( 'status' => 412 ) ); } } // Get the content-type. $type = array_shift( $headers['content_type'] ); // Include filesystem functions to get access to wp_tempnam() and wp_handle_sideload(). require_once ABSPATH . 'wp-admin/includes/file.php'; // Save the file. $tmpfname = wp_tempnam( $filename ); $fp = fopen( $tmpfname, 'w+' ); if ( ! $fp ) { return new WP_Error( 'rest_upload_file_error', __( 'Could not open file handle.' ), array( 'status' => 500 ) ); } fwrite( $fp, $data ); fclose( $fp ); // Now, sideload it in. $file_data = array( 'error' => null, 'tmp_name' => $tmpfname, 'name' => $filename, 'type' => $type, ); $size_check = self::check_upload_size( $file_data ); if ( is_wp_error( $size_check ) ) { return $size_check; } $overrides = array( 'test_form' => false, ); $sideloaded = wp_handle_sideload( $file_data, $overrides, $time ); if ( isset( $sideloaded['error'] ) ) { @unlink( $tmpfname ); return new WP_Error( 'rest_upload_sideload_error', $sideloaded['error'], array( 'status' => 500 ) ); } return $sideloaded; } /** * Parses filename from a Content-Disposition header value. * * As per RFC6266: * * content-disposition = "Content-Disposition" ":" * disposition-type *( ";" disposition-parm ) * * disposition-type = "inline" | "attachment" | disp-ext-type * ; case-insensitive * disp-ext-type = token * * disposition-parm = filename-parm | disp-ext-parm * * filename-parm = "filename" "=" value * | "filename*" "=" ext-value * * disp-ext-parm = token "=" value * | ext-token "=" ext-value * ext-token = * * @since 4.7.0 * * @link https://tools.ietf.org/html/rfc2388 * @link https://tools.ietf.org/html/rfc6266 * * @param string[] $disposition_header List of Content-Disposition header values. * @return string|null Filename if available, or null if not found. */ public static function get_filename_from_disposition( $disposition_header ) { // Get the filename. $filename = null; foreach ( $disposition_header as $value ) { $value = trim( $value ); if ( ! str_contains( $value, ';' ) ) { continue; } list( , $attr_parts ) = explode( ';', $value, 2 ); $attr_parts = explode( ';', $attr_parts ); $attributes = array(); foreach ( $attr_parts as $part ) { if ( ! str_contains( $part, '=' ) ) { continue; } list( $key, $value ) = explode( '=', $part, 2 ); $attributes[ trim( $key ) ] = trim( $value ); } if ( empty( $attributes['filename'] ) ) { continue; } $filename = trim( $attributes['filename'] ); // Unquote quoted filename, but after trimming. if ( str_starts_with( $filename, '"' ) && str_ends_with( $filename, '"' ) ) { $filename = substr( $filename, 1, -1 ); } } return $filename; } /** * Retrieves the query params for collections of attachments. * * @since 4.7.0 * * @return array Query parameters for the attachment collection as an array. */ public function get_collection_params() { $params = parent::get_collection_params(); $params['status']['default'] = 'inherit'; $params['status']['items']['enum'] = array( 'inherit', 'private', 'trash' ); $media_types = $this->get_media_types(); $params['media_type'] = array( 'default' => null, 'description' => __( 'Limit result set to attachments of a particular media type.' ), 'type' => 'string', 'enum' => array_keys( $media_types ), ); $params['mime_type'] = array( 'default' => null, 'description' => __( 'Limit result set to attachments of a particular MIME type.' ), 'type' => 'string', ); return $params; } /** * Handles an upload via multipart/form-data ($_FILES). * * @since 4.7.0 * @since 6.6.0 Added the `$time` parameter. * * @param array $files Data from the `$_FILES` superglobal. * @param array $headers HTTP headers from the request. * @param string|null $time Optional. Time formatted in 'yyyy/mm'. Default null. * @return array|WP_Error Data from wp_handle_upload(). */ protected function upload_from_file( $files, $headers, $time = null ) { if ( empty( $files ) ) { return new WP_Error( 'rest_upload_no_data', __( 'No data supplied.' ), array( 'status' => 400 ) ); } // Verify hash, if given. if ( ! empty( $headers['content_md5'] ) ) { $content_md5 = array_shift( $headers['content_md5'] ); $expected = trim( $content_md5 ); $actual = md5_file( $files['file']['tmp_name'] ); if ( $expected !== $actual ) { return new WP_Error( 'rest_upload_hash_mismatch', __( 'Content hash did not match expected.' ), array( 'status' => 412 ) ); } } // Pass off to WP to handle the actual upload. $overrides = array( 'test_form' => false, ); // Bypasses is_uploaded_file() when running unit tests. if ( defined( 'DIR_TESTDATA' ) && DIR_TESTDATA ) { $overrides['action'] = 'wp_handle_mock_upload'; } $size_check = self::check_upload_size( $files['file'] ); if ( is_wp_error( $size_check ) ) { return $size_check; } // Include filesystem functions to get access to wp_handle_upload(). require_once ABSPATH . 'wp-admin/includes/file.php'; $file = wp_handle_upload( $files['file'], $overrides, $time ); if ( isset( $file['error'] ) ) { return new WP_Error( 'rest_upload_unknown_error', $file['error'], array( 'status' => 500 ) ); } return $file; } /** * Retrieves the supported media types. * * Media types are considered the MIME type category. * * @since 4.7.0 * * @return array Array of supported media types. */ protected function get_media_types() { $media_types = array(); foreach ( get_allowed_mime_types() as $mime_type ) { $parts = explode( '/', $mime_type ); if ( ! isset( $media_types[ $parts[0] ] ) ) { $media_types[ $parts[0] ] = array(); } $media_types[ $parts[0] ][] = $mime_type; } return $media_types; } /** * Determine if uploaded file exceeds space quota on multisite. * * Replicates check_upload_size(). * * @since 4.9.8 * * @param array $file $_FILES array for a given file. * @return true|WP_Error True if can upload, error for errors. */ protected function check_upload_size( $file ) { if ( ! is_multisite() ) { return true; } if ( get_site_option( 'upload_space_check_disabled' ) ) { return true; } $space_left = get_upload_space_available(); $file_size = filesize( $file['tmp_name'] ); if ( $space_left < $file_size ) { return new WP_Error( 'rest_upload_limited_space', /* translators: %s: Required disk space in kilobytes. */ sprintf( __( 'Not enough space to upload. %s KB needed.' ), number_format( ( $file_size - $space_left ) / KB_IN_BYTES ) ), array( 'status' => 400 ) ); } if ( $file_size > ( KB_IN_BYTES * get_site_option( 'fileupload_maxk', 1500 ) ) ) { return new WP_Error( 'rest_upload_file_too_big', /* translators: %s: Maximum allowed file size in kilobytes. */ sprintf( __( 'This file is too big. Files must be less than %s KB in size.' ), get_site_option( 'fileupload_maxk', 1500 ) ), array( 'status' => 400 ) ); } // Include multisite admin functions to get access to upload_is_user_over_quota(). require_once ABSPATH . 'wp-admin/includes/ms.php'; if ( upload_is_user_over_quota( false ) ) { return new WP_Error( 'rest_upload_user_quota_exceeded', __( 'You have used your space quota. Please delete files before uploading.' ), array( 'status' => 400 ) ); } return true; } /** * Gets the request args for the edit item route. * * @since 5.5.0 * * @return array */ protected function get_edit_media_item_args() { return array( 'src' => array( 'description' => __( 'URL to the edited image file.' ), 'type' => 'string', 'format' => 'uri', 'required' => true, ), 'modifiers' => array( 'description' => __( 'Array of image edits.' ), 'type' => 'array', 'minItems' => 1, 'items' => array( 'description' => __( 'Image edit.' ), 'type' => 'object', 'required' => array( 'type', 'args', ), 'oneOf' => array( array( 'title' => __( 'Rotation' ), 'properties' => array( 'type' => array( 'description' => __( 'Rotation type.' ), 'type' => 'string', 'enum' => array( 'rotate' ), ), 'args' => array( 'description' => __( 'Rotation arguments.' ), 'type' => 'object', 'required' => array( 'angle', ), 'properties' => array( 'angle' => array( 'description' => __( 'Angle to rotate clockwise in degrees.' ), 'type' => 'number', ), ), ), ), ), array( 'title' => __( 'Crop' ), 'properties' => array( 'type' => array( 'description' => __( 'Crop type.' ), 'type' => 'string', 'enum' => array( 'crop' ), ), 'args' => array( 'description' => __( 'Crop arguments.' ), 'type' => 'object', 'required' => array( 'left', 'top', 'width', 'height', ), 'properties' => array( 'left' => array( 'description' => __( 'Horizontal position from the left to begin the crop as a percentage of the image width.' ), 'type' => 'number', ), 'top' => array( 'description' => __( 'Vertical position from the top to begin the crop as a percentage of the image height.' ), 'type' => 'number', ), 'width' => array( 'description' => __( 'Width of the crop as a percentage of the image width.' ), 'type' => 'number', ), 'height' => array( 'description' => __( 'Height of the crop as a percentage of the image height.' ), 'type' => 'number', ), ), ), ), ), ), ), ), 'rotation' => array( 'description' => __( 'The amount to rotate the image clockwise in degrees. DEPRECATED: Use `modifiers` instead.' ), 'type' => 'integer', 'minimum' => 0, 'exclusiveMinimum' => true, 'maximum' => 360, 'exclusiveMaximum' => true, ), 'x' => array( 'description' => __( 'As a percentage of the image, the x position to start the crop from. DEPRECATED: Use `modifiers` instead.' ), 'type' => 'number', 'minimum' => 0, 'maximum' => 100, ), 'y' => array( 'description' => __( 'As a percentage of the image, the y position to start the crop from. DEPRECATED: Use `modifiers` instead.' ), 'type' => 'number', 'minimum' => 0, 'maximum' => 100, ), 'width' => array( 'description' => __( 'As a percentage of the image, the width to crop the image to. DEPRECATED: Use `modifiers` instead.' ), 'type' => 'number', 'minimum' => 0, 'maximum' => 100, ), 'height' => array( 'description' => __( 'As a percentage of the image, the height to crop the image to. DEPRECATED: Use `modifiers` instead.' ), 'type' => 'number', 'minimum' => 0, 'maximum' => 100, ), ); } } Gann Fan Trading Strategy Insights and Backtest Results |

The 1X2 means the angle is moving one unit of price for every two units of time. Finally, the 2X1 moves two units of price with one unit of time. Using the same formula, angles can also be 1X8, 1X4, 4X1, and 8X1.

Traders should also be aware that Gann Fans alone may generate false signals. Combining them with technical indicators like moving averages, RSI, and MACD helps improve accuracy and confirm current prices. Gann Fan is a technical indicator used to assess price movements for financial instruments. Traders use it to find support and resistance levels in a technical chart through a series of angles and lines.

Backtesting is no sure thing, but at least you have an idea that something has worked in the past. If you know how to backtest you can develop a portfolio of trading strategies pretty fast. There is no best trading strategy because you need many to smooth returns. Ensure you get backtesting results of any Gann fan strategy you create. But https://traderoom.info/definition-of-gunn-fan-trading-strategy/ you should keep in mind that past performance does not guarantee future results.

Learning to Decode the Gann Fan Indicator

  • One of the biggest challenges traders face is subjectivity when analyzing charts.
  • Gann Fans are a versatile and powerful tool for visualizing trend strength, forecasting support and resistance, and enhancing your trading strategy.
  • Gann believed that past, present, and future market actions are interconnected, giving traders a way to analyze and forecast market movements.
  • In sideways markets, false signals can increase, so it’s crucial to test on your specific asset and timeframe.
  • These code snippets show how to calculate the highest and lowest closes over a given period, which can be used to plot Gann Fan bands.

In the chart below, you can see two trade setups with different Gann fan strategies. The first one (on the left) is a buy setup from a trend-following strategy. The second one is a reversal strategy where the price hit the 1/1 line and reversed, giving a short-selling signal. The best way to use Gann Fan is in conjunction with other technical analysis tools, such as trend lines and moving averages.

The Gann Fan is based on the idea that prices move in predictable patterns and that these patterns can be identified and used to make trading decisions. Traders often use Gann Fans in conjunction with other technical analysis tools, such as chart patterns and indicators, to make trading decisions. Some traders use Gann Fans to identify potential entry and exit points, while others use them to identify potential price targets. In a little while, we will see that these lines from a technical point of view will become our support and resistance levels.

Gann fan trading strategy

For example, a swing trader might use a longer length to capture major trends, while a scalper could use a shorter length for quick entries and exits. Institutional traders may develop proprietary configurations based on historical volatility or market structure. This API receives a list of prices and returns the upper and lower Gann Fan levels for the specified period. You can use this as a backend for web apps, trading dashboards, or automated systems.

  • You may have seen the Gann Fan in your trading platform and be wondering how to use the tool for trading.
  • Before you think of using it in your trading, make sure you back-test it to know whether it has any merit.
  • A price movement that crosses over one of these lines can be a sign of changing market sentiment.
  • Price movement above this angle suggests a strong bull market, while movement below it signals a bearish market.

Backtesting & Performance

Either aggressively on the break or alternatively wait and look for price to retrace after the break to find support in the same area. A common buy strategy is using resistance breaks and support bounces for entry. The tool projects 9 lines from a selected significant high or low, selected by the trader. This point has been identified as the start of an up or down trend. A bearish sentiment is typically considered when price stays below the 45 degree line in a downtrend. When price stays above the 45 degree line on an uptrend the sentiment is considered bullish.

How Gann Indicators Work

A Gann Fan breakout is more reliable when MACD is above zero and experiencing a bullish crossover. If MACD is negative despite a rising Gann Fan signal, the market may lack the strength to sustain the move. To overcome these challenges, systematic traders refine their strategies through backtesting and adjusting their use of Gann Fans based on broader market conditions. Backtesting is crucial when using any trading strategy so you can be confident that your rules are actually profitable. Since Gann Fans are difficult to backtest, I would recommend they be avoided in practice.

To improve trading decisions, traders should instead use other trading indicators that can be objectively coded and backtested. This way we can build enough confidence in our trading strategies to follow them consistently. The biggest challenge is the subjectivity in selecting the starting point for the fan. Choosing the wrong swing high or low can distort signals and lead to false conclusions.

What Are Gann Fans?

If the price drops below the 1×1 line, it suggests a bearish direction, favoring short trades. Traders can also use the Gann Fan for breakout strategies, entering trades when the price moves above or below a fan line with strong momentum. Another approach is the reversal strategy, where the price consistently fails to break above a fan line, signaling potential resistance. Gann Fan trading strategies primarily use the nine diagonal lines as 1.

I want to emphasize here that while the Gann Fan may be popular, it is essentially impossible to backtest objectively and so does not deserve a place in the systematic trader’s toolkit. My preference is to only trade strategies that can be fully backtested and coded objectively so they do not rely on subjective judgement to make the decisions. Anything less than this leads to inconsistent trading decisions and erratic results.

It has been observed that Gann Fan has been gaining a lot of importance in the financial market for the purpose of analyzing the trajectory or trend of assets and their price movement. It has become trendy among investors not only to detect price action and strength of price direction but also to determine the shifts or highs and lows at which prices change. However, the indicator may vary based on the chart platform used and also the market volatility. Gann angles are calculated by drawing lines at certain angles from a significant price point, such as a high or low.

Key Takeaways

Gann fan indicators and oscillators are technical analysis tools, developed by Robert Krausz, which are based on the work of W.D. Gann and are used to identify potential support and resistance levels for a security. Another limitation is that Gann Fan angles depend on the price axis and time axis. If the time scale and price scales are not properly adjusted, the Gann Fan angles may not reflect accurate support and resistance levels.