org.yawlfoundation.yawl.util
Class YPredicateParser

java.lang.Object
  org.yawlfoundation.yawl.util.YPredicateParser

Direct Known Subclasses:

DynTextParser, LogPredicateParser, YLogPredicateDecompositionParser, YLogPredicateParameterParser, YLogPredicateWorkItemParser, YNetElementDocoParser

public class YPredicateParser
extends Object

Parses strings, replacing substrings within of the form ${expression} with the result of the expression evaluation Author: Michael Adams Date: 02/04/2010 Known subclasses: logging.YLogPredicateDecompositionParser, logging.YLogPredicateParameterParser, logging.YLogPredicateWorkItemParser, resourcing.util.LogPredicateParser, resourcing.jsf.dynform.DynTextParser Subclasses should override the 'valueOf' method to handle their own pre-parsing.

Constructor Summary

YPredicateParser()

Method Summary

protected String	dateTimeString(long time) Converts a time value to a full date & time string
protected String	evaluateQuery(String s, org.jdom.Element data) Evaluates an XQuery embedded within a delimited expression
protected String	evaluateXQuery(String s, org.jdom.Document dataDoc)
protected String	evaluateXQuery(String s, org.jdom.Element data) Evaluates an XQuery
protected String	getAttributeValue(Map<String,String> map, String s) Extracts a key from the delimited expression passed, then seeks the value corresponding to that key from the map passed
protected String	namesToCSV(Set<String> names) Transforms a Set of Strings into a string of comma separated values
String	parse(String s) Parses a string, replacing substrings within of the form ${expression} with the result of the expression evaluation
protected String	stripDelimiters(String s) removes the surrounding ${...} from a String
protected String	valueOf(String s) Evaluates an expression and returns the result.

Methods inherited from class java.lang.Object

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

Constructor Detail

YPredicateParser

public YPredicateParser()

Method Detail

parse

public String parse(String s)

Parses a string, replacing substrings within of the form ${expression} with the result of the expression evaluation

Parameters:

s - the string to parse

Returns:

s, with any embedded expressions replaced with their evaluations

valueOf

protected String valueOf(String s)

Evaluates an expression and returns the result. Subclasses should override this class to do their own expression evaluations before calling this version for any general expression evaluations.

Parameters:

s - the string representing the expression, of the form ${expression}

Returns:

the result of the expression evaluation, or the unchanged string if the expression is unrecognised

dateTimeString

protected String dateTimeString(long time)

Converts a time value to a full date & time string

Parameters:

time - the time value

Returns:

a string representing the date & time value

getAttributeValue

protected String getAttributeValue(Map<String,String> map,
                                   String s)

Extracts a key from the delimited expression passed, then seeks the value corresponding to that key from the map passed

Parameters:

map - a map of String pairs

s - a string representing an expression, of the form ${expression:key}, containing the key

Returns:

the corresponding key value, or null if the map is null or the map does not contain the key

namesToCSV

protected String namesToCSV(Set<String> names)

Transforms a Set of Strings into a string of comma separated values

Parameters:

names - the Set of Strings to transform

Returns:

a string containing each of the Strings in the Set, spearated by a comma, or "Nil" if there are no Strings in the Set

evaluateQuery

protected String evaluateQuery(String s,
                               org.jdom.Element data)

Evaluates an XQuery embedded within a delimited expression

Parameters:

s - the delimited expression, either of the form ${query} or ${expression:query}

data - XML'd data that may be referenced by the expression. May be null if the expression doesn't reference any data

Returns:

the result of the evaluation, or "__evaluation_error__" if there's a problem evaluating the expression

evaluateXQuery

protected String evaluateXQuery(String s,
                                org.jdom.Element data)

Evaluates an XQuery

Parameters:

s - the query expression

data - XML'd data that may be referenced by the expression. May be null if the expression doesn't reference any data

Returns:

the result of the evaluation, or "__evaluation_error__" if there's a problem evaluating the expression

evaluateXQuery

protected String evaluateXQuery(String s,
                                org.jdom.Document dataDoc)

stripDelimiters

protected String stripDelimiters(String s)

removes the surrounding ${...} from a String

Parameters:

s - the delimited String

Returns:

the inner contents of the String with the delimiters removed