Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Source OMG Systems Modeling Language (SysML) 1.6 Copyright information About Object Management Group copyright in text extracts quoted from OMG specifications for educational purposes Snippet kind NOTATION UML keywords Message MessageEnd Previous snippet Full quote 17.4.4.1 Message A message is shown as a line from the sender MessageEnd to the receiver MessageEnd. The line must be such that every line fragment is either horizontal or downwards when traversed from send event to receive event. Next snippet The send and receive events may both be on the same lifeline. Related snippets Related snippets (backlinks) The form of the line or arrowhead reflects properties of the message An asynchronous Message (messageSort equals asynchCall or asynchSignal) has an open arrow head. A synchronous Message (messageSort equals synchCall) has a filled arrow head. A reply Message (messageSort equals reply) has a dashed line with either an open or filled arrow head. An object creation Message (messageSort equals createMessage) has a dashed line with an open arrow head. An object deletion Message (messageSort equals deleteMessage) must end in a DestructionOccurrenceSpecification. A lost Message is denoted with a small black circle at the arrow end of the Message. A found Message is denoted with a small black circle at the starting end of the Message. On Communication Diagrams, the Messages are decorated by a small arrow in the direction of the Message close to the Message name and sequence number along the line between the lifelines ... A reply-message-label is used for reply Messages. It has the following form ... The message-name appearing in a reply-message-label is the name property of the Message. If the Message has a signature, this will be the name of the Operation referenced by the signature (which should be the Operation for whose call this is a reply). Otherwise the name is unconstrained. A reply-message-label may optionally have an assignment-target given to the left of the message-name, with a corresponding returned value denoted by the optional value-specification given after a colon at the end of the reply-message-label. If the Message has a signature that is an Operation with a return parameter, then this assignment-target and/or value-specification corresponds to the argument for that parameter (if no assignment-target is given, it is considered to be unknown). If the Message has a signature without a return parameter, then no assignment-target or value-specification may be given for the reply-message-label as a whole. If a reply Message does not have a signature, then the only argument that may be specified for it is a return argument as specified above. If a reply Message does not have a signature, then the only argument that may be specified for it is a return argument as specified above. However, if the Message has a signature that is an Operation with out or inout ownedParameters, then ... An output-argument always explicitly names the parameter to which it is to be matched. Any parameters that are not named are considered to have implicit wildcard arguments. (There is thus no need for an explicit wildcard notation for output-arguments.) If a reply-message-label does not include an output-argument-list and the Message has a signature, then this denotes that the Message has wildcard arguments corresponding to all out and inout ownedParameters of the signature Operation (if any). Note that the parentheses are not considered part of the output-argument list, so a reply-message-label without an output-argument-list may still optionally include an empty set of parentheses (“()”) after the message-name. An output-argument with an explicit assignment-target given may also optionally include a value-specification. If a value-specification is given, then this denotes the returned value for the argument. Otherwise the argument has no modeled returned value If an output-argument does not have an explicit assignment-target specified, it is considered to have an unknown assignment target. In this case, it is required to include a value-specification, which denotes the returned value for the argument. If the identity of a reply Message is obvious (e.g., when its sendEvent is the only reply within the extent of an ExecutionOccurence where there is only one receipt of an Operation call message), the label may be omitted to simplify the diagram. If the reply Message has a signature, then wildcard arguments are provided for all return, out and inout ownedParameters of the signature Operation. Visit also Visit also (backlinks) Flags
