CIP Visual Basic.NET documentation for interface "IpfcRelationFunctionListener"

Interface IpfcRelationFunctionListener

Description

Listener providing the implementation for external functions registered by this application and capable of being used in relations.

Direct Parent Classes:: IpfcActionListener

Method Summary


`Sub`	`AssignValue (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues, Assignment as IpfcParamValue)`
	Function called to evaluate a custom relation function invoked on the left hand side of a relation.

`Function`	`CheckArguments (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues) as Boolean`
	To check the validity of arguments of external function.

`Function`	`EvaluateFunction (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues) as IpfcParamValue`
	Function called to evaluate a custom relation function invoked on the right hand side of a relation.

Method Detail

Sub AssignValue (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues, Assignment as IpfcParamValue)

Function called to evaluate a custom relation function invoked on the left hand side of a relation.

Parameters:

Owner: Owner item of the relations
FunctionName: Name of the external function.
Arguments: Arguments passed by the relation to the external function.
Assignment: The right hand side of the relation to be used in the assignment.

Function CheckArguments (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues) as Boolean

To check the validity of arguments of external function.

This method can be used to check the contents of the arguments. If you want to restrict the arguments to be a certain number and a certain type, use the optional argument IpfcRelationFunctionOptions.ArgumentTypes instead.

Parameters:

Owner: Owner item of the relations
FunctionName: Name of the external function.
Arguments: Arguments passed by the relation to the external function.

Returns:: true or false depending on the check.

Function EvaluateFunction (Owner as IpfcRelationOwner, FunctionName as String, Arguments as IpfcParamValues) as IpfcParamValue

Function called to evaluate a custom relation function invoked on the right hand side of a relation.

Parameters:

Owner: Owner item of the relations
FunctionName: Name of the external function.
Arguments: Arguments passed by the relation to the external function.

Returns:: The result of the relation function calculation.