org.apache.commons.digester.xmlrules
Class DigesterRuleParser

java.lang.Object
  |
  +--org.apache.commons.digester.RuleSetBase
        |
        +--org.apache.commons.digester.xmlrules.DigesterRuleParser

All Implemented Interfaces:

RuleSet

public class DigesterRuleParser

extends RuleSetBase

This is a RuleSet that parses XML into Digester rules, and then adds those rules to a 'target' Digester.

Author:

David H. Martin - Initial Contribution, Scott Sanders - Added ASL, removed external dependencies, Bradley M. Handy - Bean Property Setter Rule addition

Nested Class Summary

private class	DigesterRuleParser.BeanPropertySetterRuleFactory Factory for creating a BeanPropertySetterRule.
protected class	DigesterRuleParser.CallMethodRuleFactory Factory for creating a CallMethodRule.
protected class	DigesterRuleParser.CallParamRuleFactory Factory for creating a CallParamRule.
protected class	DigesterRuleParser.FactoryCreateRuleFactory Factory for creating a FactoryCreateRule
private class	DigesterRuleParser.IncludeRule A rule for including one rules XML file within another.
protected class	DigesterRuleParser.ObjectCreateRuleFactory Factory for creating a ObjectCreateRule
private class	DigesterRuleParser.PatternRule A rule for extracting the pattern matching strings from the rules XML.
protected class	DigesterRuleParser.PatternStack A stack whose toString method returns a '/'-separated concatenation of all the elements in the stack.
private class	DigesterRuleParser.RulesPrefixAdapter Wraps a Rules object.
protected class	DigesterRuleParser.SetNextRuleFactory Factory for creating a SetNextRuleFactory
protected class	DigesterRuleParser.SetPropertiesAliasRule A rule for adding a attribute-property alias to the custom alias mappings of the containing SetPropertiesRule rule.
protected class	DigesterRuleParser.SetPropertiesRuleFactory Factory for creating a SetPropertiesRule
protected class	DigesterRuleParser.SetPropertyRuleFactory Factory for creating a SetPropertyRule
protected class	DigesterRuleParser.SetTopRuleFactory Factory for creating a SetTopRuleFactory

Field Summary

static java.lang.String	DIGESTER_PUBLIC_ID
private java.lang.String	digesterDtdUrl path to the DTD
private java.util.Set	includedFiles Used to detect circular includes
protected DigesterRuleParser.PatternStack	patternStack A stack used to maintain the current pattern.
protected Digester	targetDigester This is the digester to which we are adding the rules that we parse from the Rules XML document.

Fields inherited from class org.apache.commons.digester.RuleSetBase

namespaceURI

Constructor Summary

	DigesterRuleParser() Constructs a DigesterRuleParser.
	DigesterRuleParser(Digester targetDigester) Constructs a rule set for converting XML digester rule descriptions into Rule objects, and adding them to the given Digester
private	DigesterRuleParser(Digester targetDigester, DigesterRuleParser.PatternStack stack, java.util.Set includedFiles) Constructs a rule set for parsing an XML digester rule file that has been included within an outer XML digester rule file.

Method Summary

void	add(Rule rule) Adds a rule the the target digester.
void	addRuleInstances(Digester digester) Add to the given digester the set of Rule instances used to parse an XML document defining Digester rules.
protected java.lang.String	getDigesterRulesDTD() Returns the location of the DTD used to validate the digester rules XML document.
void	setDigesterRulesDTD(java.lang.String dtdURL) Sets the location of the digester rules DTD.
void	setTarget(Digester d) Sets the digester into which to add the parsed rules

Methods inherited from class org.apache.commons.digester.RuleSetBase

getNamespaceURI

Methods inherited from class java.lang.Object

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

Field Detail

DIGESTER_PUBLIC_ID

public static final java.lang.String DIGESTER_PUBLIC_ID

See Also:

Constant Field Values

digesterDtdUrl

private java.lang.String digesterDtdUrl

path to the DTD

targetDigester

protected Digester targetDigester

This is the digester to which we are adding the rules that we parse from the Rules XML document.

patternStack

protected DigesterRuleParser.PatternStack patternStack

A stack used to maintain the current pattern. The Rules XML document type allows nesting of patterns. If an element defines a matching pattern, the resulting pattern is a concatenation of that pattern with all the ancestor elements' patterns. Hence the need for a stack.

includedFiles

private java.util.Set includedFiles

Used to detect circular includes

Constructor Detail

DigesterRuleParser

public DigesterRuleParser()

Constructs a DigesterRuleParser. This object will be inoperable until the target digester is set, via setTarget(Digester)

DigesterRuleParser

public DigesterRuleParser(Digester targetDigester)

Constructs a rule set for converting XML digester rule descriptions into Rule objects, and adding them to the given Digester

Parameters:

targetDigester - the Digester to add the rules to

DigesterRuleParser

private DigesterRuleParser(Digester targetDigester,
                           DigesterRuleParser.PatternStack stack,
                           java.util.Set includedFiles)

Constructs a rule set for parsing an XML digester rule file that has been included within an outer XML digester rule file. In this case, we must pass the pattern stack and the target digester to the rule set, as well as the list of files that have already been included, for cycle detection.

Parameters:

targetDigester - the Digester to add the rules to

stack - Stack containing the prefix pattern string to be prepended to any pattern parsed by this rule set.

Method Detail

setTarget

public void setTarget(Digester d)

Sets the digester into which to add the parsed rules

Parameters:

d - the Digester to add the rules to

setDigesterRulesDTD

public void setDigesterRulesDTD(java.lang.String dtdURL)

Sets the location of the digester rules DTD. This is the DTD used to validate the rules XML file.

getDigesterRulesDTD

protected java.lang.String getDigesterRulesDTD()

Returns the location of the DTD used to validate the digester rules XML document.

add

public void add(Rule rule)

Adds a rule the the target digester. After a rule has been created by parsing the XML, it is added to the digester by calling this method. Typically, this method is called via reflection, when executing a SetNextRule, from the Digester that is parsing the rules XML.

Parameters:

rule - a Rule to add to the target digester.

addRuleInstances

public void addRuleInstances(Digester digester)

Add to the given digester the set of Rule instances used to parse an XML document defining Digester rules. When the digester parses an XML file, it will add the resulting rules & patterns to the 'target digester' that was passed in this RuleSet's constructor.

If you extend this class to support additional rules, your implementation should of this method should call this implementation first: i.e. super.addRuleInstances(digester);

Specified by:

addRuleInstances in interface RuleSet

Specified by:

addRuleInstances in class RuleSetBase

Parameters:

digester - Digester instance to which the new Rule instances should be added.