Class PropertyParser

java.lang.Object
org.apache.fop.fo.expr.PropertyTokenizer
org.apache.fop.fo.expr.PropertyParser
public final class PropertyParser extends PropertyTokenizer
Class to parse XSL-FO property expressions. This class is heavily based on the epxression parser in James Clark's XT, an XSLT processor.

  • Field Details

  • Constructor Details

    • PropertyParser

      private PropertyParser(String propExpr, PropertyInfo pInfo)
      Private constructor. Called by the static parse() method.
      Parameters:
      propExpr - The specified value (attribute on the xml element).
      pInfo - A PropertyInfo object representing the context in which the property expression is to be evaluated.

  • Method Details

    • parse

      public static Property parse(String expr, PropertyInfo propInfo) throws PropertyException
      Public entrypoint to the Property expression parser.
      Parameters:
      expr - The specified value (attribute on the xml element).
      propInfo - A PropertyInfo object representing the context in which the property expression is to be evaluated.
      Returns:
      A Property object holding the parsed result.
      Throws:
      PropertyException - If the "expr" cannot be parsed as a Property.

    • parseProperty

      private Property parseProperty() throws PropertyException
      Parse the property expression described in the instance variables. Note: If the property expression String is empty, a StringProperty object holding an empty String is returned.
      Returns:
      A Property object holding the parsed result.
      Throws:
      PropertyException - If the "expr" cannot be parsed as a Property.

    • parseAdditiveExpr

      private Property parseAdditiveExpr() throws PropertyException
      Try to parse an addition or subtraction expression and return the resulting Property.
      Throws:
      PropertyException

    • parseMultiplicativeExpr

      private Property parseMultiplicativeExpr() throws PropertyException
      Try to parse a multiply, divide or modulo expression and return the resulting Property.
      Throws:
      PropertyException

    • parseUnaryExpr

      private Property parseUnaryExpr() throws PropertyException
      Try to parse a unary minus expression and return the resulting Property.
      Throws:
      PropertyException

    • expectRpar

      private void expectRpar() throws PropertyException
      Checks that the current token is a right parenthesis and throws an exception if this isn't the case.
      Throws:
      PropertyException

    • parsePrimaryExpr

      private Property parsePrimaryExpr() throws PropertyException
      Try to parse a primary expression and return the resulting Property. A primary expression is either a parenthesized expression or an expression representing a primitive Property datatype, such as a string literal, an NCname, a number or a unit expression, or a function call expression.
      Throws:
      PropertyException

    • parseArgs

      Property[] parseArgs(Function function) throws PropertyException
      Parse a comma separated list of function arguments. Each argument may itself be an expression. This method consumes the closing right parenthesis of the argument list.
      Parameters:
      function - The function object for which the arguments are collected.
      Returns:
      An array of Property objects representing the arguments found.
      Throws:
      PropertyException - If the number of arguments found isn't equal to the number expected or if another argument parsing error occurs.

    • evalAddition

      private Property evalAddition(Numeric op1, Numeric op2) throws PropertyException
      Evaluate an addition operation. If either of the arguments is null, this means that it wasn't convertible to a Numeric value.
      Parameters:
      op1 - A Numeric object (Number or Length-type object)
      op2 - A Numeric object (Number or Length-type object)
      Returns:
      A new NumericProperty object holding an object which represents the sum of the two operands.
      Throws:
      PropertyException - If either operand is null.

    • evalSubtraction

      private Property evalSubtraction(Numeric op1, Numeric op2) throws PropertyException
      Evaluate a subtraction operation. If either of the arguments is null, this means that it wasn't convertible to a Numeric value.
      Parameters:
      op1 - A Numeric object (Number or Length-type object)
      op2 - A Numeric object (Number or Length-type object)
      Returns:
      A new NumericProperty object holding an object which represents the difference of the two operands.
      Throws:
      PropertyException - If either operand is null.

    • evalNegate

      private Property evalNegate(Numeric op) throws PropertyException
      Evaluate a unary minus operation. If the argument is null, this means that it wasn't convertible to a Numeric value.
      Parameters:
      op - A Numeric object (Number or Length-type object)
      Returns:
      A new NumericProperty object holding an object which represents the negative of the operand (multiplication by *1).
      Throws:
      PropertyException - If the operand is null.

    • evalMultiply

      private Property evalMultiply(Numeric op1, Numeric op2) throws PropertyException
      Evaluate a multiplication operation. If either of the arguments is null, this means that it wasn't convertible to a Numeric value.
      Parameters:
      op1 - A Numeric object (Number or Length-type object)
      op2 - A Numeric object (Number or Length-type object)
      Returns:
      A new NumericProperty object holding an object which represents the product of the two operands.
      Throws:
      PropertyException - If either operand is null.

    • evalDivide

      private Property evalDivide(Numeric op1, Numeric op2) throws PropertyException
      Evaluate a division operation. If either of the arguments is null, this means that it wasn't convertible to a Numeric value.
      Parameters:
      op1 - A Numeric object (Number or Length-type object)
      op2 - A Numeric object (Number or Length-type object)
      Returns:
      A new NumericProperty object holding an object which represents op1 divided by op2.
      Throws:
      PropertyException - If either operand is null.

    • evalModulo

      private Property evalModulo(Number op1, Number op2) throws PropertyException
      Evaluate a modulo operation. If either of the arguments is null, this means that it wasn't convertible to a Number value.
      Parameters:
      op1 - A Number object
      op2 - A Number object
      Returns:
      A new NumberProperty object holding an object which represents op1 mod op2.
      Throws:
      PropertyException - If either operand is null.