org.apache.commons.digester3.plugins
Class PluginRules

java.lang.Object
  org.apache.commons.digester3.plugins.PluginRules

All Implemented Interfaces:

Rules

public class PluginRules
extends Object
implements Rules

A custom digester Rules manager which must be used as the Rules object when using the plugins module functionality.

During parsing, a linked list of PluginCreateRule instances develop, and this list also acts like a stack. The original instance that was set before the Digester started parsing is always at the tail of the list, and the Digester always holds a reference to the instance at the head of the list in the rules member. Initially, this list/stack holds just one instance, ie head and tail are the same object.

When the start of an xml element causes a PluginCreateRule to fire, a new PluginRules instance is created and inserted at the head of the list (ie pushed onto the stack of Rules objects). Digester.getRules() therefore returns this new Rules object, and any custom rules associated with that plugin are added to that instance.

When the end of the xml element is encountered (and therefore the PluginCreateRule end method fires), the stack of Rules objects is popped, so that Digester.getRules returns the previous Rules object.

Since:

1.6

Field Summary

protected Digester

digester The Digester instance with which this Rules instance is associated.

Constructor Summary

PluginRules()
Constructor for top-level Rules objects.

PluginRules(Rules decoratedRules)
Constructor for top-level Rules object which handles rule-matching using the specified implementation.

Method Summary

void	add(String pattern, Rule rule) Register a new Rule instance matching the specified pattern.
void	clear() Clear all rules.
Digester	getDigester() Return the Digester instance with which this instance is associated.
String	getNamespaceURI() Return the namespace URI that will be applied to all subsequently added Rule objects.
Rules	getParent() Return the parent Rules object.
String	getPluginClassAttr() See PluginContext.getPluginClassAttr().
String	getPluginClassAttrNs() See PluginContext.getPluginClassAttrNs().
String	getPluginIdAttr() See PluginContext.getPluginIdAttr().
String	getPluginIdAttrNs() See PluginContext.getPluginIdAttrNs().
PluginManager	getPluginManager() Return the object which "knows" about all declared plugins.
List<RuleFinder>	getRuleFinders() See PluginContext.getRuleFinders().
RulesFactory	getRulesFactory() Return the rules factory object (or null if one has not been specified).
List<Rule>	match(String namespaceURI, String path, String name, Attributes attributes) Return a List of all registered Rule instances that match the specified nesting pattern, or a zero-length List if there are no matches.
List<Rule>	rules() Return the list of rules registered with this object, in the order they were registered with this object.
void	setDigester(Digester digester) Set the Digester instance with which this Rules instance is associated.
void	setNamespaceURI(String namespaceURI) Set the namespace URI that will be applied to all subsequently added Rule objects.
void	setPluginClassAttribute(String namespaceUri, String attrName) See PluginContext.setPluginClassAttribute(java.lang.String, java.lang.String).
void	setPluginIdAttribute(String namespaceUri, String attrName) See PluginContext.setPluginIdAttribute(java.lang.String, java.lang.String).
void	setRuleFinders(List<RuleFinder> ruleFinders) See PluginContext.setRuleFinders(java.util.List).
void	setRulesFactory(RulesFactory factory) Set the object which is used to generate the new Rules instances created to hold and process the rules associated with each plugged-in class.

Methods inherited from class java.lang.Object

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

Field Detail

digester

protected Digester digester

The Digester instance with which this Rules instance is associated.

Constructor Detail

PluginRules

public PluginRules()

Constructor for top-level Rules objects. Exactly one of these must be created and installed into the Digester instance as the Rules object before parsing starts.

PluginRules

public PluginRules(Rules decoratedRules)

Constructor for top-level Rules object which handles rule-matching using the specified implementation.

Parameters:

decoratedRules - The top-level Rules object which handles rule-matching using the specified implementation.

Method Detail

getParent

public Rules getParent()

Return the parent Rules object.

Returns:

the parent Rules object.

getDigester

public Digester getDigester()

Return the Digester instance with which this instance is associated.

Specified by:

getDigester in interface Rules

Returns:

the Digester instance with which this instance is associated.

setDigester

public void setDigester(Digester digester)

Set the Digester instance with which this Rules instance is associated.

Specified by:

setDigester in interface Rules

Parameters:

digester - The newly associated Digester instance

getNamespaceURI

public String getNamespaceURI()

Return the namespace URI that will be applied to all subsequently added Rule objects.

Specified by:

getNamespaceURI in interface Rules

Returns:

the namespace URI that will be applied to all subsequently added Rule objects.

setNamespaceURI

public void setNamespaceURI(String namespaceURI)

Set the namespace URI that will be applied to all subsequently added Rule objects.

Specified by:

setNamespaceURI in interface Rules

Parameters:

namespaceURI - Namespace URI that must match on all subsequently added rules, or null for matching regardless of the current namespace URI

getPluginManager

public PluginManager getPluginManager()

Return the object which "knows" about all declared plugins.

Returns:

The pluginManager value

getRuleFinders

public List<RuleFinder> getRuleFinders()

See PluginContext.getRuleFinders().

Returns:

the list of RuleFinder objects

setRuleFinders

public void setRuleFinders(List<RuleFinder> ruleFinders)

See PluginContext.setRuleFinders(java.util.List).

Parameters:

ruleFinders - the list of RuleFinder objects

getRulesFactory

public RulesFactory getRulesFactory()

Return the rules factory object (or null if one has not been specified).

Returns:

the rules factory object.

setRulesFactory

public void setRulesFactory(RulesFactory factory)

Set the object which is used to generate the new Rules instances created to hold and process the rules associated with each plugged-in class.

Parameters:

factory - the rules factory object

rules

public List<Rule> rules()

Return the list of rules registered with this object, in the order they were registered with this object.

Note that Rule objects stored in parent Rules objects are not returned by this method.

Specified by:

rules in interface Rules

Returns:

list of all Rule objects known to this Rules instance.

add

public void add(String pattern,
                Rule rule)

Register a new Rule instance matching the specified pattern.

Specified by:

add in interface Rules

Parameters:

pattern - Nesting pattern to be matched for this Rule. This parameter treats equally patterns that begin with and without a leading slash ('/').

rule - Rule instance to be registered

clear

public void clear()

Clear all rules.

Specified by:

clear in interface Rules

match

public List<Rule> match(String namespaceURI,
                        String path,
                        String name,
                        Attributes attributes)

Return a List of all registered Rule instances that match the specified nesting pattern, or a zero-length List if there are no matches. If more than one Rule instance matches, they must be returned in the order originally registered through the add() method.

Specified by:

match in interface Rules

Parameters:

namespaceURI - Namespace URI for which to select matching rules, or null to match regardless of namespace URI

path - Nesting pattern to be matched

name - the local name if the parser is namespace aware, or just the element name otherwise

attributes - The attribute list of the current matching element

Returns:

a List of all registered Rule instances that match the specified nesting pattern

setPluginClassAttribute

public void setPluginClassAttribute(String namespaceUri,
                                    String attrName)

See PluginContext.setPluginClassAttribute(java.lang.String, java.lang.String).

Parameters:

namespaceUri - is the namespace uri that the specified attribute is in. If the attribute is in no namespace, then this should be null. Note that if a namespace is used, the attrName value should not contain any kind of namespace-prefix. Note also that if you are using a non-namespace-aware parser, this parameter must be null.

attrName - is the attribute whose value contains the name of the class to be instantiated.

setPluginIdAttribute

public void setPluginIdAttribute(String namespaceUri,
                                 String attrName)

See PluginContext.setPluginIdAttribute(java.lang.String, java.lang.String).

Parameters:

namespaceUri - is the namespace uri that the specified attribute is in. If the attribute is in no namespace, then this should be null. Note that if a namespace is used, the attrName value should not contain any kind of namespace-prefix. Note also that if you are using a non-namespace-aware parser, this parameter must be null.

attrName - is the attribute whose value contains the id of the plugin declaration to be used when instantiating an object.

getPluginClassAttrNs

public String getPluginClassAttrNs()

See PluginContext.getPluginClassAttrNs().

Returns:

the namespace for the xml attribute which indicates which class is to be plugged in.

getPluginClassAttr

public String getPluginClassAttr()

See PluginContext.getPluginClassAttr().

Returns:

the namespace for the xml attribute which indicates which class is to be plugged in.

getPluginIdAttrNs

public String getPluginIdAttrNs()

See PluginContext.getPluginIdAttrNs().

Returns:

the namespace for the xml attribute which indicates which previous plugin declaration should be used.

getPluginIdAttr

public String getPluginIdAttr()

See PluginContext.getPluginIdAttr().

Returns:

the namespace for the xml attribute which indicates which previous plugin declaration should be used.