Add action hooks to media modal

[dhruvang21]

Trac ticket: https://core.trac.wordpress.org/ticket/65086

Use of AI Tools

AI assistance: Yes
Tool(s): Claude code
Model(s): opus 4.6
Used for: used for documentation and code review.

Example plugin integration

// my-ai-plugin/js/generate-alt-text.js
wp.hooks.addAction(
	'media.view.attachment.renderFieldAfter',
	'my-ai-plugin/generate-alt-text',
	function( $setting, context ) {
		// Only inject beside the alt text field.
		if ( 'alt' !== context.field ) {
			return;
		}

		// Avoid double-injection on repeated renders.
		if ( $setting.find( '.my-ai-generate-alt' ).length ) {
			return;
		}

		var $button = $( '<button>', {
			type:  'button',
			class: 'button button-small my-ai-generate-alt',
			text:  wp.i18n.__( 'Generate', 'my-ai-plugin' ),
		} );

		$button.on( 'click', function() {
			var attachment = context.attachment;
			var $textarea  = $setting.find( 'textarea' );

			$button.prop( 'disabled', true ).text( wp.i18n.__( 'Generating…', 'my-ai-plugin' ) );

			wp.apiFetch( {
				path: '/my-ai-plugin/v1/generate-alt',
				method: 'POST',
				data: { attachment_id: attachment.get( 'id' ) },
			} ).then( function( response ) {
				// Update the Backbone model — triggers save via existing event binding.
				attachment.set( 'alt', response.alt_text );
				$textarea.val( response.alt_text ).trigger( 'change' );
			} ).catch( function() {
				// Surface error accessibly.
				wp.a11y.speak( wp.i18n.__( 'Could not generate alt text.', 'my-ai-plugin' ) );
			} ).finally( function() {
				$button.prop( 'disabled', false ).text( wp.i18n.__( 'Generate', 'my-ai-plugin' ) );
			} );
		} );

		$setting.append( $button );
	}
);

// Edit media screen
add_filter( 'attachment_fields_to_edit', function( $fields, $post ) {
    $fields['my_ai_generate_alt'] = array(
        'label'         => '',
        'input'         => 'html',
        'html'          => '<button type="button" class="button my-ai-generate-alt" data-id="' . esc_attr( $post->ID ) . '">'
                            . esc_html__( 'Generate Alt Text', 'my-ai-plugin' )
                            . '</button>',
        'show_in_edit'  => true,
        'show_in_modal' => false, // keep it out of the modal's compat meta
    );
    return $fields;
}, 10, 2 );

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[github-actions]

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