<?php
namespace Classifai\Features;
use Classifai\Providers\Azure\ComputerVision;
use Classifai\Services\ImageProcessing;
use WP_REST_Server;
use WP_REST_Request;
use WP_Error;
use DOMDocument;
use function Classifai\get_asset_info;
use function Classifai\clean_input;
/**
* Class ImageTextExtraction
*/
class ImageTextExtraction extends Feature {
/**
* ID of the current feature.
*
* @var string
*/
const ID = 'feature_image_to_text_generator';
/**
* Constructor.
*/
public function __construct() {
$this->label = __( 'Image Text Extraction', 'classifai' );
// Contains all providers that are registered to the service.
$this->provider_instances = $this->get_provider_instances( ImageProcessing::get_service_providers() );
// Contains just the providers this feature supports.
$this->supported_providers = [
ComputerVision::ID => __( 'Microsoft Azure AI Vision', 'classifai' ),
];
}
/**
* Set up necessary hooks.
*
* We utilize this so we can register the REST route.
*/
public function setup() {
parent::setup();
add_action( 'rest_api_init', [ $this, 'register_endpoints' ] );
}
/**
* Set up necessary hooks.
*/
public function feature_setup() {
add_action( 'rest_api_init', [ $this, 'add_ocr_data_to_api_response' ] );
add_action( 'enqueue_block_editor_assets', [ $this, 'enqueue_editor_assets' ] );
add_action( 'add_meta_boxes_attachment', [ $this, 'setup_attachment_meta_box' ] );
add_action( 'edit_attachment', [ $this, 'maybe_rescan_image' ] );
add_filter( 'the_content', [ $this, 'add_ocr_aria_describedby' ] );
add_filter( 'attachment_fields_to_edit', [ $this, 'add_rescan_button_to_media_modal' ], 10, 2 );
add_filter( 'wp_generate_attachment_metadata', [ $this, 'generate_ocr_text' ], 9, 2 );
}
/**
* Register any needed endpoints.
*/
public function register_endpoints() {
register_rest_route(
'classifai/v1',
'ocr/(?P<id>\d+)',
[
'methods' => WP_REST_Server::READABLE,
'callback' => [ $this, 'rest_endpoint_callback' ],
'args' => [
'id' => [
'required' => true,
'type' => 'integer',
'sanitize_callback' => 'absint',
'description' => esc_html__( 'Image ID to read text from.', 'classifai' ),
],
],
'permission_callback' => [ $this, 'image_text_extractor_permissions_check' ],
]
);
}
/**
* Check if a given request has access to generate OCR.
*
* @param WP_REST_Request $request Request object.
* @return bool|WP_Error
*/
public function image_text_extractor_permissions_check( WP_REST_Request $request ) {
$attachment_id = $request->get_param( 'id' );
$post_type = get_post_type_object( 'attachment' );
// Ensure attachments are allowed in REST endpoints.
if ( empty( $post_type ) || empty( $post_type->show_in_rest ) ) {
return false;
}
// Ensure we have a logged in user that can upload and change files.
if ( empty( $attachment_id ) || ! current_user_can( 'edit_post', $attachment_id ) || ! current_user_can( 'upload_files' ) ) {
return false;
}
if ( ! $this->is_feature_enabled() ) {
return new WP_Error( 'not_enabled', esc_html__( 'Scan image for text is disabled. Please check your settings.', 'classifai' ) );
}
return true;
}
/**
* Generic request handler for all our custom routes.
*
* @param WP_REST_Request $request The full request object.
* @return \WP_REST_Response
*/
public function rest_endpoint_callback( WP_REST_Request $request ) {
$route = $request->get_route();
if ( strpos( $route, '/classifai/v1/ocr' ) === 0 ) {
$result = $this->run( $request->get_param( 'id' ), 'ocr' );
if ( $result && ! is_wp_error( $result ) ) {
$this->save( $result, $request->get_param( 'id' ) );
}
return rest_ensure_response( $result );
}
return parent::rest_endpoint_callback( $request );
}
/**
* Generate the tags for the image being uploaded.
*
* @param array $metadata The metadata for the image.
* @param int $attachment_id Post ID for the attachment.
* @return array
*/
public function generate_ocr_text( array $metadata, int $attachment_id ): array {
if ( ! $this->is_feature_enabled() ) {
return $metadata;
}
$result = $this->run( $attachment_id, 'ocr' );
if ( $result && ! is_wp_error( $result ) ) {
$this->save( $result, $attachment_id );
}
return $metadata;
}
/**
* Save the OCR text.
*
* @param string $result The result to save.
* @param int $attachment_id The attachment ID.
*/
public function save( string $result, int $attachment_id ) {
$content = get_the_content( null, false, $attachment_id );
$post_args = [
'ID' => $attachment_id,
'post_content' => sanitize_text_field( $result ),
];
/**
* Filter the post arguments before saving the text to post_content.
*
* This enables text to be stored in a different post or post meta field,
* or do other post data setting based on scan results.
*
* @since 1.6.0
* @hook classifai_ocr_text_post_args
*
* @param {string} $post_args Array of post data for the attachment post update. Defaults to `ID` and `post_content`.
* @param {int} $attachment_id ID of the attachment post.
* @param {object} $result The full scan results from the API.
*
* @return {string} The filtered text data.
*/
$post_args = apply_filters( 'classifai_ocr_text_post_args', $post_args, $attachment_id, $result );
if ( $content !== $result ) {
wp_update_post( $post_args );
}
}
/**
* Include classifai_computer_vision_ocr in API response.
*/
public function add_ocr_data_to_api_response() {
register_rest_field(
'attachment',
'classifai_has_ocr',
[
'get_callback' => function ( $params ) {
return ! empty( get_post_meta( $params['id'], 'classifai_computer_vision_ocr', true ) );
},
'schema' => [
'type' => 'boolean',
'context' => [ 'view' ],
],
]
);
}
/**
* Enqueue the editor scripts.
*/
public function enqueue_editor_assets() {
wp_enqueue_script(
'classifai-plugin-editor-ocr-js',
CLASSIFAI_PLUGIN_URL . 'dist/classifai-plugin-editor-ocr.js',
array_merge( get_asset_info( 'classifai-plugin-editor-ocr', 'dependencies' ), array( 'lodash' ) ),
get_asset_info( 'classifai-plugin-editor-ocr', 'version' ),
true
);
}
/**
* Adds a meta box for rescanning options if the settings are configured.
*
* @param \WP_Post $post The post object.
*/
public function setup_attachment_meta_box( \WP_Post $post ) {
global $wp_meta_boxes;
if ( ! wp_attachment_is_image( $post ) || ! $this->is_feature_enabled() ) {
return;
}
// Add our content to the metabox.
add_action( 'classifai_render_attachment_metabox', [ $this, 'attachment_data_meta_box_content' ] );
// If the metabox was already registered, don't add it again.
if ( isset( $wp_meta_boxes['attachment']['side']['high']['classifai_image_processing'] ) ) {
return;
}
// Register the metabox if needed.
add_meta_box(
'classifai_image_processing',
__( 'ClassifAI Image Processing', 'classifai' ),
[ $this, 'attachment_data_meta_box' ],
'attachment',
'side',
'high'
);
}
/**
* Render the meta box.
*
* @param \WP_Post $post The post object.
*/
public function attachment_data_meta_box( \WP_Post $post ) {
/**
* Allows more fields to be rendered in attachment metabox.
*
* @since 3.0.0
* @hook classifai_render_attachment_metabox
*
* @param {WP_Post} $post The post object.
* @param {object} $this The Provider object.
*/
do_action( 'classifai_render_attachment_metabox', $post, $this );
}
/**
* Display meta data.
*
* @param \WP_Post $post The post object.
*/
public function attachment_data_meta_box_content( \WP_Post $post ) {
$ocr = get_post_meta( $post->ID, 'classifai_computer_vision_ocr', true ) ? __( 'Rescan for text', 'classifai' ) : __( 'Scan image for text', 'classifai' );
?>
<?php if ( $this->is_feature_enabled() ) : ?>
<div class="misc-pub-section">
<label for="rescan-ocr">
<input type="checkbox" value="yes" id="rescan-ocr" name="rescan-ocr"/>
<?php echo esc_html( $ocr ); ?>
</label>
</div>
<?php
endif;
}
/**
* Determine if we need to rescan the image.
*
* @param int $attachment_id Attachment ID.
*/
public function maybe_rescan_image( int $attachment_id ) {
if ( clean_input( 'rescan-ocr' ) ) {
$result = $this->run( $attachment_id, 'ocr' );
if ( $result && ! is_wp_error( $result ) ) {
// Ensure we don't re-run this when the attachment is updated.
remove_action( 'edit_attachment', [ $this, 'maybe_rescan_image' ] );
$this->save( $result, $attachment_id );
}
}
}
/**
* Filter the post content to inject aria-describedby attribute.
*
* @param string $content Post content.
* @return string
*/
public function add_ocr_aria_describedby( string $content ): string {
$modified = false;
if ( ! is_singular() || empty( $content ) ) {
return $content;
}
$dom = new DOMDocument();
// Suppress warnings generated by loadHTML.
$errors = libxml_use_internal_errors( true );
$dom->loadHTML(
sprintf(
'<!DOCTYPE html><html><head><meta charset="%s"></head><body>%s</body></html>',
esc_attr( get_bloginfo( 'charset' ) ),
$content
)
);
libxml_use_internal_errors( $errors );
foreach ( $dom->getElementsByTagName( 'img' ) as $image ) {
foreach ( $image->attributes as $attribute ) {
if ( 'aria-describedby' === $attribute->name ) {
break;
}
if ( 'class' !== $attribute->name ) {
continue;
}
$image_id = preg_match( '~wp-image-\K\d+~', $image->getAttribute( 'class' ), $out ) ? $out[0] : 0;
$ocr_scanned_text_id = "classifai-ocr-$image_id";
$ocr_scanned_text = $dom->getElementById( $ocr_scanned_text_id );
if ( ! empty( $ocr_scanned_text ) ) {
$image->setAttribute( 'aria-describedby', $ocr_scanned_text_id );
$modified = true;
}
}
}
if ( $modified ) {
$body = $dom->getElementsByTagName( 'body' )->item( 0 );
return trim( $dom->saveHTML( $body ) );
}
return $content;
}
/**
* Adds the rescan buttons to the media modal.
*
* @param array $form_fields Array of fields
* @param \WP_Post $post Post object for the attachment being viewed.
* @return array
*/
public function add_rescan_button_to_media_modal( array $form_fields, \WP_Post $post ): array {
if ( ! $this->is_feature_enabled() || ! wp_attachment_is_image( $post ) ) {
return $form_fields;
}
$ocr_text = empty( get_post_meta( $post->ID, 'classifai_computer_vision_ocr', true ) ) ? __( 'Scan', 'classifai' ) : __( 'Rescan', 'classifai' );
$form_fields['rescan_ocr'] = [
'label' => __( 'Scan image for text', 'classifai' ),
'input' => 'html',
'show_in_edit' => false,
'html' => '<button class="button secondary" id="classifai-rescan-ocr" data-id="' . esc_attr( absint( $post->ID ) ) . '">' . esc_html( $ocr_text ) . '</button><span class="spinner" style="display:none;float:none;"></span><span class="error" style="display:none;color:#bc0b0b;padding:5px;"></span>',
];
return $form_fields;
}
/**
* Get the description for the enable field.
*
* @return string
*/
public function get_enable_description(): string {
return esc_html__( 'OCR detects text in images (e.g., handwritten notes) and saves that as content with the image.', 'classifai' );
}
/**
* Returns the default settings for the feature.
*
* @return array
*/
public function get_feature_default_settings(): array {
return [
'provider' => ComputerVision::ID,
];
}
/**
* Generates feature setting data required for migration from
* ClassifAI < 3.0.0 to 3.0.0
*
* @return array
*/
public function migrate_settings() {
$old_settings = get_option( 'classifai_computer_vision', array() );
$new_settings = $this->get_default_settings();
$new_settings['provider'] = 'ms_computer_vision';
if ( isset( $old_settings['enable_smart_cropping'] ) ) {
$new_settings['status'] = $old_settings['enable_smart_cropping'];
}
if ( isset( $old_settings['url'] ) ) {
$new_settings['ms_computer_vision']['endpoint_url'] = $old_settings['url'];
}
if ( isset( $old_settings['api_key'] ) ) {
$new_settings['ms_computer_vision']['api_key'] = $old_settings['api_key'];
}
if ( isset( $old_settings['authenticated'] ) ) {
$new_settings['ms_computer_vision']['authenticated'] = $old_settings['authenticated'];
}
if ( isset( $old_settings['ocr_roles'] ) ) {
$new_settings['roles'] = $old_settings['ocr_roles'];
}
if ( isset( $old_settings['ocr_users'] ) ) {
$new_settings['users'] = $old_settings['ocr_users'];
}
if ( isset( $old_settings['ocr_user_based_opt_out'] ) ) {
$new_settings['user_based_opt_out'] = $old_settings['ocr_user_based_opt_out'];
}
return $new_settings;
}
}