net.sf.saxon.functions
Class FormatNumber

java.lang.Object
  |
  +--net.sf.saxon.expr.ComputedExpression
        |
        +--net.sf.saxon.expr.FunctionCall
              |
              +--net.sf.saxon.functions.SystemFunction
                    |
                    +--net.sf.saxon.functions.FormatNumber

All Implemented Interfaces:

Expression, java.io.Serializable, XSLTFunction

public class FormatNumber

extends SystemFunction

implements XSLTFunction

This is the original XSLT 1.0 implementation of format-number using the JDK directly. It is still available for the time being under the name format-number-1.0, in case the new version has problems.

See Also:

Serialized Form

Field Summary

 

Fields inherited from class net.sf.saxon.functions.SystemFunction

operation

 

Fields inherited from class net.sf.saxon.expr.FunctionCall

argument

 

Fields inherited from class net.sf.saxon.expr.ComputedExpression

lineNumber, NO_ARGUMENTS, staticProperties

 

Constructor Summary

FormatNumber()

 

Method Summary
void	checkArguments(StaticContext env)           Method called during static type checking
java.lang.String	evaluateAsString(XPathContext context)           Evaluate in a context where a string is wanted
Item	evaluateItem(XPathContext c)           Evaluate in a general context
java.lang.String	formatNumber(double n, java.lang.String format, java.text.DecimalFormatSymbols dfs)           Here is the method that does the work.
Expression	preEvaluate(StaticContext env)           preEvaluate: this method suppresses compile-time evaluation by doing nothing.

 

Methods inherited from class net.sf.saxon.functions.SystemFunction

addContextDocumentArgument, computeCardinality, display, getDetails, getItemType, getName, getRequiredType, main, makeSystemFunction, useContextItemAsDefault

 

Methods inherited from class net.sf.saxon.expr.FunctionCall

analyze, checkArgumentCount, getNumberOfArguments, getSubExpressions, promote, setArguments, simplify, simplifyArguments

 

Methods inherited from class net.sf.saxon.expr.ComputedExpression

computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSourceLocator, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Constructor Detail

FormatNumber

public FormatNumber()

checkArguments

public void checkArguments(StaticContext env)
                    throws XPathException

Description copied from class: SystemFunction

Method called during static type checking

Overrides:

checkArguments in class SystemFunction

XPathException

preEvaluate

public Expression preEvaluate(StaticContext env)

preEvaluate: this method suppresses compile-time evaluation by doing nothing. We can't evaluate early because we don't have access to the DecimalFormatManager.

Overrides:

preEvaluate in class FunctionCall

evaluateAsString

public java.lang.String evaluateAsString(XPathContext context)
                                  throws XPathException

Evaluate in a context where a string is wanted

Specified by:

evaluateAsString in interface Expression

Overrides:

evaluateAsString in class ComputedExpression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the value of the expression, evaluated in the current context. The expression must return a string or (); if the value of the expression is (), this method returns "".

Throws:

XPathException - if any dynamic error occurs evaluating the expression

evaluateItem

public Item evaluateItem(XPathContext c)
                  throws XPathException

Evaluate in a general context

Specified by:

evaluateItem in interface Expression

Overrides:

evaluateItem in class ComputedExpression

Parameters:

c - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression

formatNumber

public java.lang.String formatNumber(double n,
                                     java.lang.String format,
                                     java.text.DecimalFormatSymbols dfs)
                              throws XPathException

Here is the method that does the work. It needs to be synchronized because it remembers information from one invocation to the next; it doesn't matter if these are in different threads but it can't be interrupted. The reason for remembering information is that getting a new DecimalFormatSymbols each time is incredibly expensive, especially with the Microsoft Java VM.

XPathException