EIdException.IfFalse Method

Raises an instance of the exception based on an expression value.

Pascal

class procedure IfFalse(
    const ACheck: Boolean; 
    const AMsg: string = ''
);

Parameters

Parameters	Description
ACheck	Condition to check for a False value.
AMsg	Exception message text to assign to the exception instance.

Description

IfFalse is a class procedure used to raise an instance of the exception class when the condition in ACheck returns a False value. As a class method, IfFalse can be called without creating a prior instance of the exception class.

When the condition in ACheck contains False, IfFalse calls Toss with the value in AMsg to raise the exception class instance.

Use IfTrue to raise an instance of the exception class when the condition in ACheck contains True.

Example

Using class methods in an Indy Exception descendant.

  EIdException.IfNotAssigned(AnObject, 'Object has not been created.');

  EIdException.IfAssigned(AnObject.Data, 'Object already has data.');

  EIdException.IfTrue(AnObject.ClosedGracefully,
    'Object connection has closed before completion.');

  EIdException.IfFalse(AnObject.Active,
    'Object connection is not open.');

  EIdException.IfNotInRange(AnObject.Port, 30000, 39999,
    'Object port number is invalid for this protocol.');

  // no exception raised... continue processing.