[Overview][Types][Classes][Procedures and functions][Index] Reference for unit 'Laz2_XPath' (#lazutils)

TXPathVariableNode.Evaluate

Evaluates the XPath expression.

Declaration

Source position: laz2_xpath.pas line 113

public function TXPathVariableNode.Evaluate(

  AContext: TXPathContext;

  AEnvironment: TXPathEnvironment

):TXPathVariable; override;

Arguments

AContext

  

Context node for the function.

AEnvironment

  

XPath environment for the evaluation.

Function result

Result for the evaluated expression.

Description

Evaluate is an overridden method used to evaluate the XPath expression and return its derived value. Evaluate implements the abstract method defined in the ancestor class.

For TXPathVariableNode, Evaluate uses the XPath environment passed in the AEnvironment argument to retrieve the value for the variable. If a variable is not found with the required name in the XPath environment, the EvaluationError method is called to raise an exception with the message in lrsEvalUnknownVariable.

Errors

Raises an exception (in EvaluationError) when the variable name does not exist in the XPath environment. Raised with the exception message in lrsEvalUnknownVariable.

See also

EvaluationError

  

Raises an exception during expression evaluation with the specified error message.


Version 4.0 Generated 2025-05-03 Home