org.apache.xerces.xni.NamespaceContext Maven / Gradle / Ivy
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* 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.xerces.xni;
import java.util.Enumeration;
/**
* Represents an interface to query namespace information.
*
* The prefix and namespace must be identical references for equal strings, thus
* each string should be internalized (@see String.intern())
* or added to the SymbolTable
*
* @see
* org.apache.xerces.util.SymbolTable
*
* @author Andy Clark, IBM
*
* @version $Id: NamespaceContext.java 447247 2006-09-18 05:23:52Z mrglavas $
*/
public interface NamespaceContext {
//
// Constants
//
/**
* The XML Namespace ("http://www.w3.org/XML/1998/namespace"). This is
* the Namespace URI that is automatically mapped to the "xml" prefix.
*/
public final static String XML_URI = "http://www.w3.org/XML/1998/namespace".intern();
/**
* XML Information Set REC
* all namespace attributes (including those named xmlns,
* whose [prefix] property has no value) have a namespace URI of http://www.w3.org/2000/xmlns/
*/
public final static String XMLNS_URI = "http://www.w3.org/2000/xmlns/".intern();
//
// NamespaceContext methods
//
/**
* Start a new Namespace context.
*
* A new context should be pushed at the beginning
* of each XML element: the new context will automatically inherit
* the declarations of its parent context, but it will also keep
* track of which declarations were made within this context.
*
*
* @see #popContext
*/
public void pushContext();
/**
* Revert to the previous Namespace context.
*
* The context should be popped at the end of each
* XML element. After popping the context, all Namespace prefix
* mappings that were previously in force are restored.
*
* Users must not attempt to declare additional Namespace
* prefixes after popping a context, unless you push another
* context first.
*
* @see #pushContext
*/
public void popContext();
/**
* Declare a Namespace prefix.
*
* This method declares a prefix in the current Namespace
* context; the prefix will remain in force until this context
* is popped, unless it is shadowed in a descendant context.
*
* Note that to declare a default Namespace, use the empty string.
* The prefixes "xml" and "xmlns" can't be rebound.
*
* Note that you must not declare a prefix after
* you've pushed and popped another Namespace.
*
* @param prefix The prefix to declare, or null for the empty
* string.
* @param uri The Namespace URI to associate with the prefix.
*
* @return true if the prefix was legal, false otherwise
*
* @see #getURI
* @see #getDeclaredPrefixAt
*/
public boolean declarePrefix(String prefix, String uri);
/**
* Look up a prefix and get the currently-mapped Namespace URI.
*
* This method looks up the prefix in the current context. If no mapping
* is found, this methods will continue lookup in the parent context(s).
* Use the empty string ("") for the default Namespace.
*
* @param prefix The prefix to look up.
*
* @return The associated Namespace URI, or null if the prefix
* is undeclared in this context.
*/
public String getURI(String prefix);
/**
* Look up a namespace URI and get one of the mapped prefix.
*
* This method looks up the namespace URI in the current context.
* If more than one prefix is currently mapped to the same URI,
* this method will make an arbitrary selection
* If no mapping is found, this methods will continue lookup in the
* parent context(s).
*
* @param uri The namespace URI to look up.
*
* @return One of the associated prefixes, or null if the uri
* does not map to any prefix.
*
* @see #getPrefix
*/
public String getPrefix(String uri);
/**
* Return a count of locally declared prefixes, including
* the default prefix if bound.
*/
public int getDeclaredPrefixCount();
/**
* Returns the prefix at the specified index in the current context.
*/
public String getDeclaredPrefixAt(int index);
/**
* Return an enumeration of all prefixes whose declarations are active
* in the current context. This includes declarations from parent contexts
* that have not been overridden.
* @return Enumeration
*/
public Enumeration getAllPrefixes();
/**
* Reset this Namespace support object for reuse.
*
*
It is necessary to invoke this method before reusing the
* Namespace support object for a new session.
*
* Note that implementations of this method need to ensure that
* the declaration of the prefixes "xmlns" and "xml" are available.
*/
public void reset();
} // interface NamespaceContext