/*
 * The Apache Software License, Version 1.1
 * 
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 * 
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache\@apache.org.
 * 
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation, and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/**
 * $Log$
 * Revision 1.1  1999/11/09 01:07:43  twl
 * Initial revision
 *
 * Revision 1.2  1999/11/08 20:44:54  rahul
 * Swat for adding in Product name and CVS comment log variable.
 *
 */

#ifndef ATTRIBUTELIST_HPP
#define ATTRIBUTELIST_HPP

#include <util/XML4CDefs.hpp>

/**
  * Interface for an element's attribute specifications.
  *
  * The SAX parser implements this interface and passes an instance
  * to the SAX application as the second argument of each startElement
  * event.
  *
  * The instance provided will return valid results only during the
  * scope of the startElement invocation (to save it for future
  * use, the application must make a copy: the AttributeListImpl
  * helper class provides a convenient constructor for doing so).
  *
  * An AttributeList includes only attributes that have been
  * specified or defaulted: #IMPLIED attributes will not be included.
  *
  * There are two ways for the SAX application to obtain information
  * from the AttributeList.  First, it can iterate through the entire
  * list:
  *
  * <pre>
  * public void startElement (String name, AttributeList atts) {
  *   for (int i = 0; i < atts.getLength(); i++) {
  *     String name = atts.getName(i);
  *     String type = atts.getType(i);
  *     String value = atts.getValue(i);
  *     [...]
  *   }
  * }
  * </pre>
  *
  * (Note that the result of getLength() will be zero if there
  * are no attributes.)
  *
  * As an alternative, the application can request the value or
  * type of specific attributes:
  *
  * <pre>
  * public void startElement (String name, AttributeList atts) {
  *   String identifier = atts.getValue("id");
  *   String label = atts.getValue("label");
  *   [...]
  * }
  * </pre>
  *
  * The AttributeListImpl helper class provides a convenience 
  * implementation for use by parser or application writers.
  *
  * $Log$
  * Revision 1.1  1999/11/09 01:07:43  twl
  * Initial revision
  *
  * Revision 1.2  1999/11/08 20:44:54  rahul
  * Swat for adding in Product name and CVS comment log variable.
  *
  * @see DocumentHandler#startElement 
  * @see AttributeListImpl#AttributeListImpl
  */

class SAX_EXPORT AttributeList
{
public:
    // -----------------------------------------------------------------------
    //  Constructors and Destructor
    // -----------------------------------------------------------------------
    /** @name Constructors and Destructor */
    //@{
    /** Default constructor */
    AttributeList()
    {
    }

    /** Destructor */
    virtual ~AttributeList()
    {
    }
    //@}

    /** @name The virtual attribute list interface */
    //@{
  /**
    * Return the number of attributes in this list.
    *
    * The SAX parser may provide attributes in any
    * arbitrary order, regardless of the order in which they were
    * declared or specified.  The number of attributes may be
    * zero.
    *
    * @return The number of attributes in the list.  
    */
    virtual unsigned int getLength() const = 0;
  /**
    * Return the name of an attribute in this list (by position).
    *
    * The names must be unique: the SAX parser shall not include the
    * same attribute twice.  Attributes without values (those declared
    * #IMPLIED without a value specified in the start tag) will be
    * omitted from the list.
    *
    * If the attribute name has a namespace prefix, the prefix
    * will still be attached.
    *
    * @param index The index of the attribute in the list (starting at 0).
    * @return The name of the indexed attribute, or null
    *         if the index is out of range.
    * @see #getLength 
    */
    virtual const XMLCh* getName(const unsigned int index) const = 0;
  /**
    * Return the type of an attribute in the list (by position).
    *
    * The attribute type is one of the strings "CDATA", "ID",
    * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES",
    * or "NOTATION" (always in upper case).
    *
    * If the parser has not read a declaration for the attribute,
    * or if the parser does not report attribute types, then it must
    * return the value "CDATA" as stated in the XML 1.0 Recommentation
    * (clause 3.3.3, "Attribute-Value Normalization").
    *
    * For an enumerated attribute that is not a notation, the
    * parser will report the type as "NMTOKEN".
    *
    * @param index The index of the attribute in the list (starting at 0).
    * @return The attribute type as a string, or
    *         null if the index is out of range.
    * @see #getLength 
    * @see #getType(String)
    */
    virtual const XMLCh* getType(const unsigned int index) const = 0;
  /**
    * Return the value of an attribute in the list (by position).
    *
    * If the attribute value is a list of tokens (IDREFS,
    * ENTITIES, or NMTOKENS), the tokens will be concatenated
    * into a single string separated by whitespace.
    *
    * @param index The index of the attribute in the list (starting at 0).
    * @return The attribute value as a string, or
    *         null if the index is out of range.
    * @see #getLength
    * @see #getValue(String)
    */
    virtual const XMLCh* getValue(const unsigned int index) const = 0;
  /**
    * Return the type of an attribute in the list (by name).
    *
    * The return value is the same as the return value for
    * getType(int).
    *
    * If the attribute name has a namespace prefix in the document,
    * the application must include the prefix here.
    *
    * @param name The name of the attribute.
    * @return The attribute type as a string, or null if no
    *         such attribute exists.
    * @see #getType(int)
    */
    virtual const XMLCh* getType(const XMLCh* const name) const = 0;
  /**
    * Return the value of an attribute in the list (by name).
    *
    * The return value is the same as the return value for
    * getValue(int).
    *
    * If the attribute name has a namespace prefix in the document,
    * the application must include the prefix here.
    *
    * @param name The name of the attribute in the list.
    * @return The attribute value as a string, or null if
    *         no such attribute exists.
    * @see #getValue(int)
    */
    virtual const XMLCh* getValue(const XMLCh* const name) const = 0;
    //@}

private :
    /** @name Constructors and operators */
    //@{
    /** Copy constructor */
    AttributeList(const AttributeList&);
    /** Assignment operator */
    void operator=(const AttributeList&);
    //@}
};

#endif