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Message

Represents a single message stored in a CPU's or vessel's :struct:`MessageQueue`.

The main message content that the sender intended to send can be retrieved using :attr:`Message:CONTENT` attribute. Other suffixes are automatically added to every message by kOS.

Messages are serializable and thus can be passed along:

// if there is a message in the ship's message queue
// we can forward it to a different CPU

// cpu1
SET CPU2 TO PROCESSOR("cpu2").
CPU2:CONNECTION:SENDMESSAGE(SHIP:MESSAGES:POP).

// cpu2
SET RECEIVED TO CORE:MESSAGES:POP.
PRINT "Original message sent at: " + RECEIVED:CONTENT:SENTAT.

Structure

.. structure:: Message

    .. list-table::
        :header-rows: 1
        :widths: 2 1 4

        * - Suffix
          - Type
          - Description

        * - :attr:`SENTAT`
          - :struct:`TimeSpan`
          - date this message was sent at
        * - :attr:`RECEIVEDAT`
          - :struct:`TimeSpan`
          - date this message was received at
        * - :attr:`SENDER`
          - :struct:`Vessel` or :struct:`Boolean`
          - vessel which has sent this message, or Boolean false if sender vessel is now gone, or Boolean true if the sender is the KSC
        * - :attr:`HASSENDER`
          - :struct:`Boolean`
          - Tests whether or not the sender vessel still exists.
        * - :attr:`CONTENT`
          - :struct:`Structure`
          - message content

Note

This type is serializable.

.. attribute:: Message:SENTAT

    :type: :struct:`TimeSpan`

    Date this message was sent at.


.. attribute:: Message:RECEIVEDAT

    :type: :struct:`TimeSpan`

    Date this message was received at.


.. attribute:: Message:SENDER

    :type: :struct:`Vessel` or :struct:`Boolean`

    Vessel which has sent this message, or a boolean false value if
    the sender vessel no longer exists, or a boolean true value if the
    message was sent from KSC.

    If the sender of the message is an existing vessel, this suffix will
    return that vessel. In all other cases, this suffix will return a
    :struct:`Boolean` with the value:

        * ``false`` if the sender of the message is a vessel that no
          longer exists (see :attr:`HASSENDER` for explanation),
        * ``true`` if the message was sent from KSC.

    You can check for this condition either by using the :attr:`HASSENDER`
    suffix, or by checking the ``:ISTYPE`` suffix of the sender to
    detect if it's really a vessel or not.


.. attribute:: Message:HASSENDER

    :type: :struct:`Boolean`

    Because there can be a delay between when the message was sent and
    when it was processed by the receiving script, it's possibile that
    the vessel that sent the message might not exist anymore.  It could
    have either exploded, or been recovered, or been merged into another
    vessel via docking. Another possible case is that the message was not
    sent from a vessel at all but from the KSC.

    You can check the value of the ``:HASSENDER`` suffix to find out if
    the sender of the message is still a valid vessel. If :attr:`HASSENDER`
    is false, then :attr:`SENDER` won't give you an object of type
    :struct:`Vessel` and instead will give you just a :struct:`Boolean`.


.. attribute:: Message:CONTENT

    :type: :struct:`Structure`

    Content of this message.