com.ocpsoft.shade.org.apache.commons.digester.Rule Maven / Gradle / Ivy
/* $Id: Rule.java 471661 2006-11-06 08:09:25Z skitching $
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.digester;
import org.xml.sax.Attributes;
/**
* Concrete implementations of this class implement actions to be taken when
* a corresponding nested pattern of XML elements has been matched.
*
* Writing a custom Rule is considered perfectly normal when using Digester,
* and is encouraged whenever the default set of Rule classes don't meet your
* requirements; the digester framework can help process xml even when the
* built-in rules aren't quite what is needed. Creating a custom Rule is
* just as easy as subclassing javax.servlet.http.HttpServlet for webapps,
* or javax.swing.Action for GUI applications.
*
* If a rule wishes to manipulate a digester stack (the default object stack,
* a named stack, or the parameter stack) then it should only ever push
* objects in the rule's begin method and always pop exactly the same
* number of objects off the stack during the rule's end method. Of course
* peeking at the objects on the stacks can be done from anywhere.
*
* Rule objects should be stateless, ie they should not update any instance
* member during the parsing process. A rule instance that changes state
* will encounter problems if invoked in a "nested" manner; this can happen
* if the same instance is added to digester multiple times or if a
* wildcard pattern is used which can match both an element and a child of the
* same element. The digester object stack and named stacks should be used to
* store any state that a rule requires, making the rule class safe under all
* possible uses.
*/
public abstract class Rule {
// ----------------------------------------------------------- Constructors
/**
* Constructor sets the associated Digester.
*
* @param digester The digester with which this rule is associated
* @deprecated The digester instance is now set in the {@link Digester#addRule} method. Use {@link #Rule()} instead.
*/
public Rule(Digester digester) {
super();
setDigester(digester);
}
/**
*
Base constructor.
* Now the digester will be set when the rule is added.
*/
public Rule() {}
// ----------------------------------------------------- Instance Variables
/**
* The Digester with which this Rule is associated.
*/
protected Digester digester = null;
/**
* The namespace URI for which this Rule is relevant, if any.
*/
protected String namespaceURI = null;
// ------------------------------------------------------------- Properties
/**
* Return the Digester with which this Rule is associated.
*/
public Digester getDigester() {
return (this.digester);
}
/**
* Set the Digester with which this Rule is associated.
*/
public void setDigester(Digester digester) {
this.digester = digester;
}
/**
* Return the namespace URI for which this Rule is relevant, if any.
*/
public String getNamespaceURI() {
return (this.namespaceURI);
}
/**
* Set the namespace URI for which this Rule is relevant, if any.
*
* @param namespaceURI Namespace URI for which this Rule is relevant,
* or null to match independent of namespace.
*/
public void setNamespaceURI(String namespaceURI) {
this.namespaceURI = namespaceURI;
}
// --------------------------------------------------------- Public Methods
/**
* This method is called when the beginning of a matching XML element
* is encountered.
*
* @param attributes The attribute list of this element
* @deprecated Use the {@link #begin(String,String,Attributes) begin}
* method with namespace and name
* parameters instead.
*/
public void begin(Attributes attributes) throws Exception {
; // The default implementation does nothing
}
/**
* This method is called when the beginning of a matching XML element
* is encountered. The default implementation delegates to the deprecated
* method {@link #begin(Attributes) begin} without the
* namespace and name parameters, to retain
* backwards compatibility.
*
* @param 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
* @param name the local name if the parser is namespace aware, or just
* the element name otherwise
* @param attributes The attribute list of this element
* @since Digester 1.4
*/
public void begin(String namespace, String name, Attributes attributes)
throws Exception {
begin(attributes);
}
/**
* 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.
*
* @param text The text of the body of this element
* @deprecated Use the {@link #body(String,String,String) body} method
* with namespace and name parameters
* instead.
*/
public void body(String text) throws Exception {
; // The default implementation does nothing
}
/**
* 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.
*
* The default implementation delegates to the deprecated method
* {@link #body(String) body} without the namespace and
* name parameters, to retain backwards compatibility.
*
* @param 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
* @param name the local name if the parser is namespace aware, or just
* the element name otherwise
* @param text The text of the body of this element
* @since Digester 1.4
*/
public void body(String namespace, String name, String text)
throws Exception {
body(text);
}
/**
* This method is called when the end of a matching XML element
* is encountered.
*
* @deprecated Use the {@link #end(String,String) end} method with
* namespace and name parameters instead.
*/
public void end() throws Exception {
; // The default implementation does nothing
}
/**
* This method is called when the end of a matching XML element
* is encountered. The default implementation delegates to the deprecated
* method {@link #end end} without the
* namespace and name parameters, to retain
* backwards compatibility.
*
* @param 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
* @param name the local name if the parser is namespace aware, or just
* the element name otherwise
* @since Digester 1.4
*/
public void end(String namespace, String name)
throws Exception {
end();
}
/**
* This method is called after all parsing methods have been
* called, to allow Rules to remove temporary data.
*/
public void finish() throws Exception {
; // The default implementation does nothing
}
}