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<?php |
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/** |
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* Alt text generation experiment implementation. |
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* |
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* @package WordPress\AI |
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*/ |
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|
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declare( strict_types=1 ); |
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|
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namespace WordPress\AI\Experiments\Alt_Text_Generation; |
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|
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use WordPress\AI\Abilities\Image\Alt_Text_Generation as Alt_Text_Generation_Ability; |
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use WordPress\AI\Abstracts\Abstract_Feature; |
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use WordPress\AI\Asset_Loader; |
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use WordPress\AI\CLI\Alt_Text_Command; |
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use WordPress\AI\Experiments\Experiment_Category; |
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|
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use function WordPress\AI\get_bulk_action_max_items; |
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|
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if ( ! defined( 'ABSPATH' ) ) { |
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exit; |
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} |
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|
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/** |
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* Alt text generation experiment. |
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* |
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* Generates accessible alternative text for images using AI vision models. |
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* |
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* @since 0.3.0 |
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*/ |
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class Alt_Text_Generation extends Abstract_Feature { |
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/** |
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* One-shot query args the bulk action redirect uses to trigger generation. |
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* |
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* @since 1.3.0 |
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* |
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* @var list<string> |
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*/ |
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private const BULK_QUERY_ARGS = array( 'wpai_bulk_alt_text', 'wpai_attachment_ids', '_wpai_bulk_nonce' ); // phpcs:ignore SlevomatCodingStandard.Classes.DisallowMultiConstantDefinition -- This is used as an array const. |
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|
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/** |
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* Nonce action signing the bulk action redirect. |
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* |
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* @since x.x.x |
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* |
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* @var string |
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*/ |
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private const BULK_NONCE_ACTION = 'wpai_bulk_alt_text'; |
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|
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/** |
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* {@inheritDoc} |
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*/ |
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public static function get_id(): string { |
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return 'alt-text-generation'; |
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} |
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|
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/** |
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* Tracks whether the media-focused assets have already been enqueued. |
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* |
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* @since 0.3.0 |
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* |
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* @var bool |
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*/ |
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private bool $media_assets_enqueued = false; |
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|
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/** |
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* {@inheritDoc} |
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*/ |
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protected function load_metadata(): array { |
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return array( |
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'label' => __( 'Alt Text Generation', 'ai' ), |
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'description' => __( 'Generates accessible alternative (alt) text for images using AI vision models, following common web accessibility guidance. Requires an AI connector that includes support for vision-based image analysis models.', 'ai' ), |
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'category' => Experiment_Category::EDITOR, |
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'capability' => 'vision', |
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); |
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} |
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|
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/** |
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* {@inheritDoc} |
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*/ |
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public function register(): void { |
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add_action( 'wp_abilities_api_init', array( $this, 'register_abilities' ) ); |
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add_action( 'enqueue_block_editor_assets', array( $this, 'enqueue_editor_assets' ) ); |
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add_action( 'wp_enqueue_media', array( $this, 'enqueue_media_frame_assets' ) ); |
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add_action( 'admin_enqueue_scripts', array( $this, 'maybe_enqueue_media_library_assets' ) ); |
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add_action( 'add_meta_boxes_attachment', array( $this, 'setup_attachment_meta_box' ) ); |
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add_filter( 'attachment_fields_to_edit', array( $this, 'add_button_to_media_modal' ), 10, 2 ); |
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add_filter( 'bulk_actions-upload', array( $this, 'register_bulk_action' ) ); |
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add_filter( 'handle_bulk_actions-upload', array( $this, 'handle_bulk_action' ), 10, 3 ); |
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add_filter( 'removable_query_args', array( $this, 'register_removable_query_args' ) ); |
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|
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if ( ! defined( 'WP_CLI' ) || ! WP_CLI ) { |
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return; |
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} |
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|
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\WP_CLI::add_command( 'ai alt-text', Alt_Text_Command::class ); |
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} |
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|
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/** |
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* Registers any needed abilities. |
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* |
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* @since 0.3.0 |
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*/ |
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public function register_abilities(): void { |
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wp_register_ability( |
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'ai/' . self::get_id(), |
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array( |
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'label' => $this->get_label(), |
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'description' => $this->get_description(), |
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'ability_class' => Alt_Text_Generation_Ability::class, |
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), |
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); |
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} |
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|
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/** |
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* Enqueues block editor assets. |
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* |
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* @since 0.3.0 |
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*/ |
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public function enqueue_editor_assets(): void { |
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Asset_Loader::enqueue_script( 'alt_text_generation', 'experiments/alt-text-generation', array( 'include_core_abilities' => true ) ); |
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Asset_Loader::localize_script( |
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'alt_text_generation', |
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'AltTextGenerationData', |
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array( |
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'enabled' => $this->is_enabled(), |
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) |
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); |
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|
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$this->maybe_enqueue_media_script(); |
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$this->maybe_enqueue_media_editor_script(); |
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} |
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|
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/** |
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* Enqueues assets whenever the core media modal is registered. |
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* |
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* @since 0.3.0 |
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*/ |
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public function enqueue_media_frame_assets(): void { |
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$this->maybe_enqueue_media_script(); |
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} |
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|
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/** |
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* Conditionally enqueues assets on media-related admin screens (e.g., upload.php). |
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* |
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* @since 0.3.0 |
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* |
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* @param string $hook_suffix Current admin page hook suffix. |
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*/ |
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public function maybe_enqueue_media_library_assets( string $hook_suffix ): void { |
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if ( ! $this->is_enabled() ) { |
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return; |
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} |
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|
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if ( in_array( $hook_suffix, array( 'upload.php', 'media-new.php' ), true ) ) { |
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$this->maybe_enqueue_media_script(); |
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$this->maybe_enqueue_bulk_script(); |
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return; |
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} |
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|
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$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null; |
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|
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if ( ! $screen || 'attachment' !== $screen->post_type ) { |
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return; |
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} |
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|
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$this->maybe_enqueue_media_script(); |
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} |
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|
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/** |
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* Shared helper to enqueue and localize the media UI script once per request. |
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* |
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* @since 0.3.0 |
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*/ |
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private function maybe_enqueue_media_script(): void { |
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if ( $this->media_assets_enqueued || ! $this->is_enabled() ) { |
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return; |
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} |
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|
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Asset_Loader::enqueue_script( 'alt_text_generation_media', 'experiments/alt-text-generation-media', array( 'include_core_abilities' => true ) ); |
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Asset_Loader::localize_script( |
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'alt_text_generation_media', |
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'AltTextGenerationMediaData', |
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array( |
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'enabled' => $this->is_enabled(), |
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) |
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); |
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|
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$this->media_assets_enqueued = true; |
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} |
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|
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/** |
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* Conditionally enqueues assets for the experimental Gutenberg media editor. |
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* |
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* Requires the Gutenberg media editor experiment or media modal experiment to be enabled. |
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* |
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* @since 1.0.0 |
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*/ |
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private function maybe_enqueue_media_editor_script(): void { |
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if ( ! is_plugin_active( 'gutenberg/gutenberg.php' ) ) { |
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return; |
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} |
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|
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$experiments = get_option( 'gutenberg-experiments' ); |
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if ( |
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! isset( $experiments['gutenberg-media-editor'] ) && |
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! isset( $experiments['gutenberg-media-editor-modal'] ) |
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) { |
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return; |
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} |
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|
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Asset_Loader::enqueue_script( |
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'alt_text_generation_media_editor', |
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'experiments/alt-text-generation-media-editor' |
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); |
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} |
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|
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/** |
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* Sets up the attachment meta box. |
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* |
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* Adds a meta box to the attachment edit screen that contains |
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* the Generate/Regenerate button. |
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* |
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* @since 0.3.0 |
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* |
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* @param \WP_Post $post The attachment post. |
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*/ |
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public function setup_attachment_meta_box( \WP_Post $post ): void { |
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if ( |
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! $this->is_enabled() || |
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! wp_attachment_is_image( $post ) |
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) { |
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return; |
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} |
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|
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add_meta_box( |
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'ai_alt_text_generation', |
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__( 'Alt Text', 'ai' ), |
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array( $this, 'render_attachment_meta_box' ), |
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'attachment', |
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); |
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} |
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|
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/** |
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* Renders the attachment meta box content. |
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* |
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* @since 0.3.0 |
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* |
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* @param \WP_Post $post The attachment post. |
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*/ |
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public function render_attachment_meta_box( \WP_Post $post ): void { |
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$button_text = empty( get_post_meta( $post->ID, '_wp_attachment_image_alt', true ) ) ? __( 'Generate', 'ai' ) : __( 'Regenerate', 'ai' ); |
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|
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printf( |
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'<div class="ai-alt-text-media-actions" style="margin-top: 16px;">' . |
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'<button id="ai-alt-text-generate-button" class="button button-secondary" type="button" data-attachment-id="%1$d">%2$s</button>' . |
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'<span class="spinner" aria-hidden="true" style="margin-inline-start: 8px; float: none;"></span>' . |
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'<p class="description" aria-live="polite" style="margin-top: 10px; line-height: 1.3;"></p>' . |
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'</div>', |
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absint( $post->ID ), |
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esc_html( $button_text ) |
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); |
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} |
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|
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/** |
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* Adds the "Generate Alt Text" option to the Media Library bulk actions menu. |
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* |
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* @since 0.7.0 |
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* |
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* @param array<string, string> $actions The existing bulk actions. |
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* @return array<string, string> The bulk actions with the generate alt text option added. |
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*/ |
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public function register_bulk_action( array $actions ): array { |
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if ( ! $this->is_enabled() ) { |
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return $actions; |
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} |
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|
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$actions['wpai_generate_alt_text'] = __( 'Generate Alt Text', 'ai' ); |
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|
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return $actions; |
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} |
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|
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/** |
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* Registers the bulk alt text trigger params as removable query args. |
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* |
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* The bulk action redirect carries `wpai_bulk_alt_text` and |
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* `wpai_attachment_ids` in the URL, and the bulk script runs whenever they |
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* are present. Listing them here lets core clean them out of the address |
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* bar on the first paint, via the canonical URL it prints in `admin_head`, |
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* so reloading the results page does not re-trigger the whole generation. |
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* The sort, pagination, and view switcher links are handled by the request |
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* URI scrub in {@see Alt_Text_Generation::maybe_enqueue_bulk_script()}. |
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* |
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* @since 1.3.0 |
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* |
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* @param list<string> $args Query args removed from admin URLs. |
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* @return list<string> Args including the bulk alt text trigger params. |
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*/ |
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public function register_removable_query_args( array $args ): array { |
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return array_merge( $args, self::BULK_QUERY_ARGS ); |
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} |
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|
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/** |
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* Handles the "Generate Alt Text" bulk action by redirecting with selected image IDs. |
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* |
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* @since 0.7.0 |
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* |
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* @param string $redirect_url The current redirect URL. |
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* @param string $doaction The bulk action being performed. |
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* @param list<int> $post_ids The list of post IDs to process. |
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* @return string The redirect URL, possibly with bulk alt text query args appended. |
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*/ |
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public function handle_bulk_action( string $redirect_url, string $doaction, array $post_ids ): string { |
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if ( 'wpai_generate_alt_text' !== $doaction || ! current_user_can( 'upload_files' ) ) { |
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return $redirect_url; |
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} |
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|
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$image_ids = array_values( array_filter( $post_ids, 'wp_attachment_is_image' ) ); |
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|
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if ( empty( $image_ids ) ) { |
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return $redirect_url; |
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} |
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|
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return add_query_arg( |
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array( |
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'wpai_bulk_alt_text' => 1, |
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'wpai_attachment_ids' => implode( ',', array_map( 'absint', $image_ids ) ), |
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'_wpai_bulk_nonce' => wp_create_nonce( self::BULK_NONCE_ACTION ), |
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), |
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$redirect_url |
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); |
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} |
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|
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/** |
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* Enqueues the bulk alt text script when a bulk action redirect is detected. |
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* |
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* @since 0.7.0 |
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*/ |
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private function maybe_enqueue_bulk_script(): void { |
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if ( ! isset( $_GET['wpai_bulk_alt_text'] ) || ! current_user_can( 'upload_files' ) ) { |
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return; |
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} |
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|
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$nonce = isset( $_GET['_wpai_bulk_nonce'] ) ? sanitize_text_field( wp_unslash( $_GET['_wpai_bulk_nonce'] ) ) : ''; |
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|
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if ( ! wp_verify_nonce( $nonce, self::BULK_NONCE_ACTION ) ) { |
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return; |
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} |
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|
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$raw_ids = isset( $_GET['wpai_attachment_ids'] ) ? sanitize_text_field( wp_unslash( $_GET['wpai_attachment_ids'] ) ) : ''; |
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$ids = array_values( array_unique( array_filter( array_map( 'absint', explode( ',', $raw_ids ) ) ) ) ); |
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|
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if ( empty( $ids ) ) { |
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return; |
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} |
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|
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// One billed model call per image, so bound the batch. |
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$max_items = get_bulk_action_max_items( $this->get_id() ); |
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$truncated_count = max( 0, count( $ids ) - $max_items ); |
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$ids = array_slice( $ids, 0, $max_items ); |
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|
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/* |
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* The trigger params have been read; scrub them from the request URI so |
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* the sort header links the list table builds from it do not carry them. |
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* Sorting links only strip `paged`, not removable query args, so this |
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* mirrors what core does for its own one-shot params in wp-admin/upload.php. |
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* The script receives the attachment IDs through wp_localize_script() |
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* below and does not need them to stay in the URL. The value is only |
| 369 |
* rewritten, not output, so no sanitization applies. |
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*/ |
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if ( isset( $_SERVER['REQUEST_URI'] ) ) { |
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$_SERVER['REQUEST_URI'] = remove_query_arg( self::BULK_QUERY_ARGS, (string) $_SERVER['REQUEST_URI'] ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized |
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} |
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|
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Asset_Loader::enqueue_script( 'alt_text_generation_bulk', 'experiments/alt-text-generation-bulk', array( 'include_core_abilities' => true ) ); |
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Asset_Loader::localize_script( |
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'alt_text_generation_bulk', |
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'AltTextGenerationBulkData', |
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array( |
| 380 |
'attachmentIds' => $ids, |
| 381 |
'truncatedCount' => $truncated_count, |
| 382 |
) |
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); |
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} |
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|
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/** |
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* Adds a button to the media modal to generate alt text. |
| 388 |
* |
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* @since 0.3.0 |
| 390 |
* |
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* @param array<string, mixed> $fields The attachment fields. |
| 392 |
* @param \WP_Post|null $post The attachment post. |
| 393 |
* @return array<string, mixed> The attachment fields with the button added. |
| 394 |
*/ |
| 395 |
public function add_button_to_media_modal( array $fields, ?\WP_Post $post ): array { |
| 396 |
if ( |
| 397 |
! $this->is_enabled() || |
| 398 |
null === $post || |
| 399 |
! wp_attachment_is_image( $post ) |
| 400 |
) { |
| 401 |
return $fields; |
| 402 |
} |
| 403 |
|
| 404 |
$button_text = empty( get_post_meta( $post->ID, '_wp_attachment_image_alt', true ) ) ? __( 'Generate', 'ai' ) : __( 'Regenerate', 'ai' ); |
| 405 |
|
| 406 |
$fields['ai_alt_text'] = array( |
| 407 |
'label' => __( 'Alt Text', 'ai' ), |
| 408 |
'input' => 'html', |
| 409 |
'show_in_edit' => false, |
| 410 |
'html' => sprintf( |
| 411 |
'<div class="ai-alt-text-media-actions">' . |
| 412 |
'<button id="ai-alt-text-generate-button" class="button button-secondary" type="button" data-attachment-id="%1$d">%2$s</button>' . |
| 413 |
'<span class="spinner" aria-hidden="true" style="margin-inline-start: 8px; float: none;"></span>' . |
| 414 |
'<p class="description" aria-live="polite" style="margin-top: 6px; font-size: 12px;"></p>' . |
| 415 |
'</div>', |
| 416 |
absint( $post->ID ), |
| 417 |
esc_html( $button_text ) |
| 418 |
), |
| 419 |
); |
| 420 |
|
| 421 |
return $fields; |
| 422 |
} |
| 423 |
} |
| 424 |
|
