BP_REST_Document_Endpoint::prepare_links( BP_Document $document )

	protected function prepare_links( $document ) {
		$base = sprintf( '/%s/%s/', $this->namespace, ( empty( $document->attachment_id ) ? 'document/folder' : $this->rest_base ) );
		$url  = $base . $document->id;

		// Entity meta.
		$links = array(
			'self'       => array(
				'href' => rest_url( $url ),
			),
			'collection' => array(
				'href' => rest_url( $base ),
			),
			'user'       => array(
				'href'       => rest_url( bp_rest_get_user_url( $document->user_id ) ),
				'embeddable' => true,
			),
		);

		if ( ! empty( $document->activity_id ) && bp_is_active( 'activity' ) ) {
			$activity_base     = sprintf( '/%s/%s/', $this->namespace, buddypress()->activity->id );
			$activity_url      = $activity_base . $document->activity_id;
			$links['activity'] = array(
				'href'       => rest_url( $activity_url ),
				'embeddable' => true,
			);
		}

		/**
		 * Filter links prepared for the REST response.
		 *
		 * @since 0.1.0
		 *
		 * @param array       $links    The prepared links of the REST response.
		 * @param BP_Document $document Document data.
		 */
		return apply_filters( 'bp_rest_document_prepare_links', $links, $document );
	}