Input Parameters

How to Use Procedures for Event Processing › Add a Procedure to an Event Map › Input Parameters

Input Parameters

A procedure accepts the following types of input parameters:

A value. Values are specified by type and value.
A constant. Constants are specified by the letter C followed by the reserved word for the constant.
Another procedure, which is evaluated when the parameter is needed and whose return value is used as the actual input parameter for the calling procedure.

Parameter Types

When you specify a direct value as a parameter, you must specify its type. Value types have a derivation hierarchy, which is shown in the following table. You can use a more specialized type for a more general type. For example, you can use a model handle in place of an unsigned integer, and you can use either of these types in place of a number.

When a parameter has a type that is not the same as or a derivative of the expected type, if the type is similar, most procedures attempt a conversion to the expected type. If a conversion fails or is not performed, an error occurs.

Note: You can use the ToUInteger procedure (provided with CA Spectrum) to convert a parameter value to an unsigned integer. Many times, this can help to avoid errors due to expected versus actual parameter types.

To specify a parameter type in a procedure, you specify a letter (a short symbol) for the type. For example, both of the parameters in the following procedure are handles (IDs), which are indicated by the letter ‘H.’ The first handle specifies the model for which to generate the event, and the second handle specifies the event to generate.

CreateEvent( { H 0x29c00003 }, { H 0xffff0000 } )

The table that follows provides a short list of parameter types, their derivation hierarchy, and their associated short symbols. For the complete list of short symbols, see EventCondition Rule.

Parameter Type	Description	Short Symbol
Object	Derivation root	N/A
List	List root	N/A
AttributeList	List of attribute values	N/A
EventVariableList	List of event variables	N/A
Attribute Value	Any possible attribute value	N/A
Number	Number root	N/A
Integer	An integer value	I
Unsigned Integer	An unsigned integer value	U
DateTime	A time value	T
ModelHandle	A model handle	H
ModelType	A model type handle	H
RelationHandle	A relation handle	H
Attribute ID	An attribute ID	a
Unsigned Long	An unsigned long (64-bit) value	L
Boolean	A Boolean value	B
Double	A real value	R
String	String root	N/A
Text String	A String value	S
Octet String	An octet String value	O
Tagged Octet String	A hexadecimal tagged octet String	X
Object ID	An object ID value	o
IP Address	An IP address	A
Variable	The value of a variable	V

Constants

You specify a constant using the letter C followed by the reserved word for the constant. For example, the following procedure creates event 0xffff0000 for the current model:

CreateEvent( {C CURRENT_MODEL}, { H 0xffff0000 } )

You can use the following list of constants in procedures in event maps:

CURRENT_EVENT: The current event, which is set in the environment automatically by the SpectroSERVER.
CURRENT_MODEL: The current model, which is set in the environment automatically by the SpectroSERVER.
RELATION_SIDE_LEFT: The model on the left side of an association.
RELATION_SIDE_RIGHT: The model on the right side of an association.
RELATION_SIDE_EITHER: The model on either side of an association.