Each event contains
an operation code, or opcode, and a set of flags. For a detailed explanation
of these constructs, see SAS Event Stream Processing: Overview. SAS
Micro Analytic Service module methods offer you the option of examining
a source window event's opcode and flags and setting the opcode
and flags of a derived event.
Note: This practice is recommended
only for advanced SAS Event Stream Processing users.
One or more flags can
be set in a given event, depending on the event opcode and circumstances.
Here are the possible flags:
DS2 and Python module
authors can add zero or more of the following special arguments to
their DS2 method or Python function signatures:
_inOpcode
populated with the
source window event opcode when the module method is called. _inOpcode
is an input argument and, if included, must appear before any output
arguments in the method signature. _inOpcode is a string type, and
its value must be insert, update, delete, upsert,
or safedelete when the method is called.
_outOpcode
used to either set
the opcode of the derived event to be omitted, or to cause no derived
event to be omitted. If _outOpcode is omitted from the method signature,
SAS Micro Analytic Service transfers the opcode of the source window
event to the derived event. This is the standard behavior under normal
circumstances. If _outOpcode is included in the method signature and
is set to missing, emission of the derived event is skipped. If _outOpcode
is included and is not set to missing, the value of _outOpcode is
used to set the opcode of the derived event. The value that is set
must be either insert, update, delete, upsert,
or safedelete. To achieve normal processing
when _outOpcode is included, the method author must also include _inOpcode
and set _outOpcode=inOpcode. _outOpcode is an output argument. Therefore,
it must appear after all input arguments in the method signature.
_outOpcodeArray
If this argument is
present, its elements are used to set the opcode of the corresponding
derived events. If _outOpcodeArray is not present, but the scalar
meta argument _outOpcode is present in the method signature, then
the value of _outOpcode is used to set every derived event’s
opcode field. If no meta arguments are present, the derived event’s
opcodes are inherited from the source event. If both _outOpcode and
_outOpcodeArray are present in the method signature, _outOpcodeArray
takes precedence.
Similar to _outOpcode,
_outOpcodeArray can be used to suppress the generation of one or more
derived events. To suppress the generation of a derived event, set
the corresponding _outOpcodeArray entry to a missing value. If _outOpcodeArray
is present in the method signature and the entire array is set to
missing, then the generation of all derived events is skipped for
that method invocation.
_inFlags
populated with the
source window flags when the module method is called. _inFlags is
a string type containing one character per source window event flag
that is set. For example, N and NR are
possible values. Reserve space for at least three characters for
the _inFlags argument. _inFlags is an input argument. Therefore,
if included, it must appear before any output arguments in the method
signature.
_outFlagsArray
If this argument is
present in the method signature, the elements of _outFlagsArray are
used to set the flags of each corresponding derived event. If the
scalar meta argument _outFlags is present in the method signature,
its value is used to set every derived event’s flags. If no
meta arguments are present, the derived event’s flags are inherited
from the source event. If both _outFlags and _outFlagsArray are present,
_outFlagsArray takes precedence.
_outFlags
used to set the flags
of the derived event to be omitted. If _outFlags is omitted from
the method signature, SAS Micro Analytic Service transfers the flags
of the source window event to the derived event. This is the standard
behavior under normal circumstances. If _outFlags is included and
is set to missing, SAS Micro Analytic Service defaults to standard
behavior and copies the source window event flags to the derived event.