Class PluginCreateRule

java.lang.Object
org.apache.commons.digester3.Rule
org.apache.commons.digester3.plugins.PluginCreateRule
All Implemented Interfaces:
InitializableRule
public class PluginCreateRule extends Rule implements InitializableRule
Allows the original rules for parsing the configuration file to define points at which plugins are allowed, by configuring a PluginCreateRule with the appropriate pattern.
Since:
1.6

  • Constructor Details

    • PluginCreateRule

      public PluginCreateRule(Class<?> baseClass)
      Create a plugin rule where the user must specify a plugin-class or plugin-id.
      Parameters:
      baseClass - is the class which any specified plugin must be descended from.

    • PluginCreateRule

      public PluginCreateRule(Class<?> baseClass, Class<?> dfltPluginClass)
      Create a plugin rule where the user may specify a plugin. If the user doesn't specify a plugin, then the default class specified in this constructor is used.
      Parameters:
      baseClass - is the class which any specified plugin must be descended from.
      dfltPluginClass - is the class which will be used if the user doesn't specify any plugin-class or plugin-id. This class will have custom rules installed for it just like a declared plugin.

    • PluginCreateRule

      public PluginCreateRule(Class<?> baseClass, Class<?> dfltPluginClass, RuleLoader dfltPluginRuleLoader)
      Create a plugin rule where the user may specify a plugin. If the user doesn't specify a plugin, then the default class specified in this constructor is used.
      Parameters:
      baseClass - is the class which any specified plugin must be descended from.
      dfltPluginClass - is the class which will be used if the user doesn't specify any plugin-class or plugin-id. This class will have custom rules installed for it just like a declared plugin.
      dfltPluginRuleLoader - is a RuleLoader instance which knows how to load the custom rules associated with this default plugin.

  • Method Details

    • setPluginClassAttribute

      public void setPluginClassAttribute(String namespaceUri, String attrName)
      Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which class should be instantiated.

      See PluginRules.setPluginClassAttribute(String, String) for more info.

      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)
      Sets the xml attribute which the input xml uses to indicate to a PluginCreateRule which plugin declaration is being referenced.

      See PluginRules.setPluginIdAttribute(String, String) for more info.

      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.

    • postRegisterInit

      public void postRegisterInit(String matchPattern)
      Called after this Rule object has been added to the list of all Rules. Note that if a single InitializableRule instance is associated with more than one pattern, then this method will be called more than once.
      Specified by:
      postRegisterInit in interface InitializableRule
      Parameters:
      matchPattern - is the digester match pattern that will trigger this rule.

    • begin

      public void begin(String namespace, String name, Attributes attributes) throws Exception
      Invoked when the Digester matches this rule against an xml element.

      A new instance of the target class is created, and pushed onto the stack. A new "private" PluginRules object is then created and set as the digester's default Rules object. Any custom rules associated with the plugin class are then loaded into that new Rules object. Finally, any custom rules that are associated with the current pattern (such as SetPropertiesRules) have their begin methods executed.

      Overrides:
      begin in class Rule
      Parameters:
      namespace - the namespace URI of the matching element, or an empty string if the parser is not namespace aware or the element has no namespace
      name - the local name if the parser is namespace aware, or just the element name otherwise
      attributes - The attribute list of this element
      Throws:
      Exception - if any error occurs

    • body

      public void body(String namespace, String name, String text) throws Exception
      This method is called when the body of a matching XML element is encountered. If the element has no body, this method is called with an empty string as the body text.
      Overrides:
      body in class Rule
      Parameters:
      namespace - the namespace URI of the matching element, or an empty string if the parser is not namespace aware or the element has no namespace
      name - the local name if the parser is namespace aware, or just the element name otherwise
      text - The text of the body of this element
      Throws:
      Exception - if any error occurs

    • end

      public void end(String namespace, String name) throws Exception
      This method is called when the end of a matching XML element is encountered.
      Overrides:
      end in class Rule
      Parameters:
      namespace - the namespace URI of the matching element, or an empty string if the parser is not namespace aware or the element has no namespace
      name - the local name if the parser is namespace aware, or just the element name otherwise
      Throws:
      Exception - if any error occurs

    • getPattern

      public String getPattern()
      Return the pattern that this Rule is associated with.

      In general, Rule instances can be associated with multiple patterns. A PluginCreateRule, however, will only function correctly when associated with a single pattern. It is possible to fix this, but I can't be bothered just now because this feature is unlikely to be used.

      Returns:
      The pattern value

    • fireBeginMethods

      public void fireBeginMethods(List<Rule> rules, String namespace, String name, Attributes list) throws Exception
      Duplicate the processing that the Digester does when firing the begin methods of rules. It would be really nice if the Digester class provided a way for this functionality to just be invoked directly.
      Parameters:
      rules - The rules which Rule.begin(String, String, Attributes) method has to be fired
      namespace - the namespace URI of the matching element, or an empty string if the parser is not namespace aware or the element has no namespace
      name - the local name if the parser is namespace aware, or just the element name otherwise
      list - The attribute list of this element
      Throws:
      Exception - if any error occurs

    • fireEndMethods

      public void fireEndMethods(List<Rule> rules, String namespaceURI, String name) throws Exception
      Duplicate the processing that the Digester does when firing the end methods of rules. It would be really nice if the Digester class provided a way for this functionality to just be invoked directly.
      Parameters:
      rules - The rules which Rule.end(String, String) method has to be fired
      namespaceURI - the namespace URI of the matching element, or an empty string if the parser is not namespace aware or the element has no namespace
      name - the local name if the parser is namespace aware, or just the element name otherwise
      Throws:
      Exception - if any error occurs