Unit 'fpexprpars' Package
[Overview][Constants][Types][Classes][Procedures and functions][Index] [#fcl]

TFPFunctionCallBack

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Internally used class for callback-based function expressions

Declaration

Source position: fpexprpars.pp line 704

type TFPFunctionCallBack = class(TFPExprFunction)

public

  constructor CreateFunction(); override;

  

Create callback function with identifier and arguments

  procedure GetNodeValue(); override;

  

Get callback function result

  property CallBack: TFPExprFunctionCallBack; [r]

  

The callback procedure for function evaluation

end;

Inheritance

TFPFunctionCallBack

  

Internally used class for callback-based function expressions

|

TFPExprFunction

  

Internally used class for representing function calls in expression trees

|

TFPExprIdentifierNode

  

Internally used class for identifier nodes in expression trees

|

TFPExprNode

  

Class for representing nodes in expression trees

|

TObject

Description

The TFPFunctionCallBack class implements function calls that are resolved using callback mechanisms rather than built-in function implementations. It extends the expression framework to allow dynamic function resolution through user-defined callback procedures.

The callback function mechanism enables applications to provide custom function implementations that can be called from within expressions. This allows for extending the expression language with application-specific functions without modifying the core expression parser.

When a callback function is called, the registered callback procedure is invoked with the function arguments and is expected to compute and return the function result.

See also

TFPExprNode

  

Class for representing nodes in expression trees


Documentation generated on: Dec 15 2025