Class FormulaFunction

java.lang.Object
org.pentaho.reporting.libraries.formula.lvalues.AbstractLValue
org.pentaho.reporting.libraries.formula.lvalues.FormulaFunction
All Implemented Interfaces:
Serializable, Cloneable, LValue

public class FormulaFunction extends AbstractLValue
A function. Formulas consist of functions, references or static values, which are connected by operators.

Functions always have a cannonical name, which must be unique and which identifies the function. Functions can have a list of parameters. The number of parameters can vary, and not all parameters need to be filled.

Functions can have required and optional parameters. Mixing required and optional parameters is not allowed. Optional parameters cannot be ommited, unless they are the last parameter in the list.

This class provides the necessary wrapper functionality to fill in the parameters.

Author:
Thomas Morgner
See Also:
  • Constructor Details

    • FormulaFunction

      public FormulaFunction(String functionName, LValue[] parameters, ParsePosition parsePosition)
    • FormulaFunction

      public FormulaFunction(String functionName, LValue[] parameters)
  • Method Details

    • initialize

      public void initialize(FormulaContext context) throws EvaluationException
      Specified by:
      initialize in interface LValue
      Overrides:
      initialize in class AbstractLValue
      Throws:
      EvaluationException
    • getFunctionName

      public String getFunctionName()
      Returns the function's name. This is the normalized name and may not be suitable for the user. Query the function's metadata to retrieve a display-name.
      Returns:
      the function's name.
    • getFunction

      public Function getFunction()
      Returns the initialized function. Be aware that this method will return null if this LValue instance has not yet been initialized.
      Returns:
      the function instance or null, if the FormulaFunction instance has not yet been initialized.
    • getMetaData

      public FunctionDescription getMetaData()
      Returns the function's meta-data. Be aware that this method will return null if this LValue instance has not yet been initialized.
      Returns:
      the function description instance or null, if the FormulaFunction instance has not yet been initialized.
    • clone

      public Object clone() throws CloneNotSupportedException
      Specified by:
      clone in interface LValue
      Overrides:
      clone in class AbstractLValue
      Throws:
      CloneNotSupportedException
    • evaluate

      public TypeValuePair evaluate() throws EvaluationException
      Throws:
      EvaluationException
    • getChildValues

      public LValue[] getChildValues()
      Returns any dependent lvalues (parameters and operands, mostly).
      Specified by:
      getChildValues in interface LValue
      Overrides:
      getChildValues in class AbstractLValue
      Returns:
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • isConstant

      public boolean isConstant()
      Checks whether the LValue is constant. Constant lvalues always return the same value.
      Returns:
      true, if the function will always return the same value.