Source

File: wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php

public function prepare_item_for_response( $post, $request ) {
		$GLOBALS['post'] = $post;

		setup_postdata( $post );

		$fields = $this->get_fields_for_response( $request );
		$data   = array();

		if ( in_array( 'author', $fields, true ) ) {
			$data['author'] = (int) $post->post_author;
		}

		if ( in_array( 'date', $fields, true ) ) {
			$data['date'] = $this->prepare_date_response( $post->post_date_gmt, $post->post_date );
		}

		if ( in_array( 'date_gmt', $fields, true ) ) {
			$data['date_gmt'] = $this->prepare_date_response( $post->post_date_gmt );
		}

		if ( in_array( 'id', $fields, true ) ) {
			$data['id'] = $post->ID;
		}

		if ( in_array( 'modified', $fields, true ) ) {
			$data['modified'] = $this->prepare_date_response( $post->post_modified_gmt, $post->post_modified );
		}

		if ( in_array( 'modified_gmt', $fields, true ) ) {
			$data['modified_gmt'] = $this->prepare_date_response( $post->post_modified_gmt );
		}

		if ( in_array( 'parent', $fields, true ) ) {
			$data['parent'] = (int) $post->post_parent;
		}

		if ( in_array( 'slug', $fields, true ) ) {
			$data['slug'] = $post->post_name;
		}

		if ( in_array( 'guid', $fields, true ) ) {
			$data['guid'] = array(
				/** This filter is documented in wp-includes/post-template.php */
				'rendered' => apply_filters( 'get_the_guid', $post->guid, $post->ID ),
				'raw'      => $post->guid,
			);
		}

		if ( in_array( 'title', $fields, true ) ) {
			$data['title'] = array(
				'raw'      => $post->post_title,
				'rendered' => get_the_title( $post->ID ),
			);
		}

		if ( in_array( 'content', $fields, true ) ) {

			$data['content'] = 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( 'excerpt', $fields, true ) ) {
			$data['excerpt'] = array(
				'raw'      => $post->post_excerpt,
				'rendered' => $this->prepare_excerpt_response( $post->post_excerpt, $post ),
			);
		}

		$context  = ! empty( $request['context'] ) ? $request['context'] : 'view';
		$data     = $this->add_additional_fields_to_object( $data, $request );
		$data     = $this->filter_response_by_context( $data, $context );
		$response = rest_ensure_response( $data );

		if ( ! empty( $data['parent'] ) ) {
			$response->add_link( 'parent', rest_url( sprintf( '%s/%s/%d', $this->namespace, $this->parent_base, $data['parent'] ) ) );
		}

		/**
		 * Filters a revision returned from the API.
		 *
		 * Allows modification of the revision right before it is returned.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_REST_Response $response The response object.
		 * @param WP_Post          $post     The original revision object.
		 * @param WP_REST_Request  $request  Request used to generate the response.
		 */
		return apply_filters( 'rest_prepare_revision', $response, $post, $request );
	}