VerticalMarker
==============

.. php:class:: VerticalMarker

    Represents a VerticalMarker on a Gantt chart

    .. php:method:: __construct(string $title, string $when, string $duration, ?string $id = null)

        Create a VerticalMarker

        :param string $title: VerticalMarker title
        :param string $when: When the VerticalMarker starts in the chart input date format (see :php:meth:`GanttChart::withDateFormat`)
        :param string $duration: VerticalMarker duration in the form *nt* where *n* is an integer and *t* is a letter indicating the duration unit, e.g. *d* for *days*
        :param ?string $id: VerticalMarker id (default: no id)
        :returns: A new ``VerticalMarker`` instance
        :rtype: VerticalMarker

    .. php:method:: withComment(string $comment): self

        Set a comment for the VerticalMarker

        :param string $comment: The comment
        :returns: A new ``VerticalMarker`` instance
        :rtype: VerticalMarker

    .. php:method:: withInteraction(string $interaction, InteractionType $type, ?string $tooltip = null, InteractionTarget $target = InteractionTarget::Self)

        Set an interaction

        :param string $interaction: Interaction text
        :param InteractionType $type: Interaction type; callback or link
        :param ?string $tooltip: Tooltip text (default: no tooltip)
        :param InteractionTarget $target: Interaction target (default: current window)
        :returns: A new ``VerticalMarker`` instance with the interaction
        :rtype: VerticalMarker