Class PluginRules

java.lang.Object
org.apache.commons.digester.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 Details

    • digester

      protected Digester digester
      The Digester instance with which this Rules instance is associated.
    • rulesFactory

      private RulesFactory rulesFactory
      The (optional) object which generates new rules instances.
    • decoratedRules

      private Rules decoratedRules
      The rules implementation that we are "enhancing" with plugins functionality, as per the Decorator pattern.
    • pluginManager

      private PluginManager pluginManager
      Object which contains information about all known plugins.
    • mountPoint

      private String mountPoint
      The path below which this rules object has responsibility. For paths shorter than or equal the mountpoint, the parent's match is called.
    • parent

      private PluginRules parent
      The Rules object that holds rules applying "above" the mountpoint, ie the next Rules object down in the stack.
    • pluginContext

      private PluginContext pluginContext
      A reference to the object that holds all data which should only exist once per digester instance.
  • Constructor Details

    • 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.
    • PluginRules

      PluginRules(Digester digester, String mountPoint, PluginRules parent, Class pluginClass) throws PluginException
      Constructs a Rules instance which has a parent Rules object (which is different from having a delegate rules object).

      One of these is created each time a PluginCreateRule's begin method fires, in order to manage the custom rules associated with whatever concrete plugin class the user has specified.

      Parameters:
      digester - is the object this rules will be associated with.
      mountPoint - is the digester match path for the element matching a PluginCreateRule which caused this "nested parsing scope" to begin. This is expected to be equal to digester.getMatch().
      parent - must be non-null.
      pluginClass - is the plugin class whose custom rules will be loaded into this new PluginRules object.
      Throws:
      PluginException
  • Method Details

    • getParent

      public Rules getParent()
      Return the parent Rules object.
    • getDigester

      public Digester getDigester()
      Return the Digester instance with which this instance is associated.
      Specified by:
      getDigester in interface Rules
    • 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
    • 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 getRuleFinders()
    • setRuleFinders

      public void setRuleFinders(List ruleFinders)
    • getRulesFactory

      public RulesFactory getRulesFactory()
      Return the rules factory object (or null if one has not been specified).
    • 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.
    • getDecoratedRules

      Rules getDecoratedRules()
      This package-scope method is used by the PluginCreateRule class to get direct access to the rules that were dynamically added by the plugin. No other class should need access to this object.
    • rules

      public List 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 match(String path)
      Deprecated.
      Call match(namespaceURI,pattern) instead.
      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:
      path - the path to the xml nodes to be matched.
    • match

      public List match(String namespaceURI, String path)
      Return a List of all registered Rule instances that match the specified nodepath, 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 - the path to the xml nodes to be matched.
    • setPluginClassAttribute

      public void setPluginClassAttribute(String namespaceUri, String attrName)
    • setPluginIdAttribute

      public void setPluginIdAttribute(String namespaceUri, String attrName)
    • getPluginClassAttrNs

      public String getPluginClassAttrNs()
    • getPluginClassAttr

      public String getPluginClassAttr()
    • getPluginIdAttrNs

      public String getPluginIdAttrNs()
    • getPluginIdAttr

      public String getPluginIdAttr()