/*

* Copyright (c) 2002-2005 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:        This class offers a set of utility functions for XML data

*

*/

#ifndef SEN_XML_UTILS_H

#define SEN_XML_UTILS_H

//  INCLUDES

#include <e32base.h>

#include <stringpool.h>

namespace Xml

    {

    // FORWARD DECLARES

    class RAttribute;

    // TYPE DEFINITIONS

    typedef RArray<RAttribute> RAttributeArray;

    }

using namespace Xml;

class CSenElement;

class CSenBaseAttribute;

// CONSTANTS

namespace

    {

    const TInt KMaxEscapedLength = 8;

/*

    // Moved to SenXmlConstants.hß

    // Five basic entities as descriptors

    _LIT8(KSenEscapedApos,     "'");

    _LIT8(KSenEscapedDblQuot,  """);

    _LIT8(KSenEscapedGt,       ">");

    _LIT8(KSenEscapedLt,       "<");

    _LIT8(KSenEscapedAmp,      "&");

    // XML-escaping chars as descriptors

    _LIT8(KSenAmpersandDesC8,  "&");

    _LIT8(KSenAposDesC8,       "\'");

    _LIT8(KSenDblQuotDesC8,    "\"");

    _LIT8(KSenGtDesC8,         ">");

    _LIT8(KSenLtDesC8,         "<");

*/    

    }

// CLASS DECLARATION

/**

*  This class offers a set of utility functions for XML data

*  The helper methods include Unicode (UCS2) and UTF-8 encoding

*  and decoding as well as convenience methods to encode and

*  decode the five basic XML entities. There are functions

*  for extracting XML prefixes and building of qualifiedname

*  and a functionality for checking if an element name value 

*  is illegal or not.

*  @lib SenXML.dll

*  @since Series60 3.0

*/

class SenXmlUtils

    {

    public: // New functions

        /**

         * Helper function to convert unicode string to UTF-8 encoded.

         * @since Series60 3.0

         * @param aUnicodeString    string to be converted.

         * @return buffer as UTF-8, caller takes ownership.

        */

        IMPORT_C static HBufC8* ToUtf8LC(const TDesC16& aUnicodeString);

        /**

         * Helper function to convert UTF-8 string to unicode encoded.

         * @since Series60 3.0

         * @param aUtf8String   string to be converted.

         * @return buffer as unicode, caller takes ownership.

         */

        IMPORT_C static HBufC16* ToUnicodeLC(const TDesC8& aUtf8String);

        /**

         * Helper function to determine if a string starts with another string.

         * @since Series60 3.0

         * @param aDes  string to be searched from.

         * @param aPrefix   the prefix to be searched.

         * @return ETrue if given string starts with given prefix, 

         *          otherwise EFalse.

         */

        IMPORT_C static TBool StartsWith(const TDesC8& aDes,

                                         const TDesC8& aPrefix);

        /**

         * Helper function to determine if a string ends with another string.

         * @since Series60 3.0

         * @param aDes  string to be searched from.

         * @param aPrefix   the prefix to be searched.

         * @return ETrue if given string ends with given prefix, 

         *          otherwise EFalse.

         */

        IMPORT_C static TBool EndsWith(const TDesC8& aDes, const TDesC8& aPostfix);

        /**

         * Helper function to find a value of a given attribute.

         * @since Series60 3.0

         * @param aAttributes   Array which contains the attributes.

         * @param aAttrName The name of the attribute which value is asked.

         * @return The value of the wanted attribute, or KNullDesC8 if given

         *          attribute name was not found.

         */

        IMPORT_C static TPtrC8  AttrValue(  const RAttributeArray& aAttributes,

                                            const TDesC8& aAttrName);

        /**

         * Get a newly allocated copy of the attribute.

         * @since Series60 3.0

         * @param apAttrs       Array which contains the attributes.

         * @param aAttrName The name of the attribute which value is asked.

         * @return A buffer containing the value of the wanted attribute.

         *          Buffer is newly allocated and ownership is transferred 

         *          to the caller. Can be NULL if attribute was not found.

         */

        IMPORT_C static HBufC8* AllocAttrValueL(const RAttributeArray& apAttrs,

                                                const TDesC8& aAttrName);

        /**

         * Helper function to construct a qualified name.

         * @since Series60 3.0

         * @param aPrefix       the prefix to be used.

         * @param aLocalName    the local name to be used.

         * @param   aQName      a ref-to-pointer which will contain the allocated

         *                      qualified name. This param should be NULL when

         *                      passed, otherwise memory leak will occur.

         *                      Caller has the ownership of this buffer.

         */

        IMPORT_C static void BuildQNameL(   const TDesC8& aPrefix, 

                                            const TDesC8& aLocalName,

                                            HBufC8*& aQName);

        /**

         * Encodes XML-escaping characters found from aOriginal 

         * to XML Basic Entities. 

         * Note, that aEncoded is not re-assigned IF there were NO

         * XML-escaping characters - '&', ''', '"', '<' or '>' -found.   

         * Otherwise, when encoding has been done, the aEncoded points

         * to newly allocated descriptor, which ownership belongs to

         * the caller (who should have given aEncoded pointer as NULL

         * in any case).

         * @since Series60 3.0

         * @param aOriginal the original descriptor.

         * @param aEncoded      a ref-to-pointer which will contain the allocated

         *                      encoded string. This param should be NULL when

         *                      passed, otherwise memory leak will occur.

         *                      Caller has the ownership of this buffer.

         */

        IMPORT_C static TBool EncodeHttpCharactersL(const TDesC8& aOriginal,

                                                    HBufC8*& aEncoded);

        /**

         * Method leaves if aCandidate contains illegal, XML-escaping characters.

         * Those characters, which will cause a leave are:

         *                           '&', ''', '"', '<' and '>'

         * @since Series60 3.0

         * @param   aCandidate  string to be checked.

         * Leave codes:

         *      KErrSenInvalidCharacters    if contains invalid characters.

         */

        IMPORT_C static void LeaveOnXmlEscapesL(const TDesC8& aCandidate); 

        /**

         * Method leaves if aCandidate contains illegal, XML-escaping characters

         * or is an empty descriptor.

         * Those characters, which will cause a leave are:

         *                           '&', ''', '"', '<' and '>'

         * @since Series60 3.0

         * @param   aCandidate  string to be checked.

         * Leave codes:

         *      KErrSenInvalidCharacters    if contains invalid characters.

         *      KErrSenZeroLengthDescriptor if aCandidate is zero length

         */

        static void LeaveOnInvalidElementNameL(const TDesC8& aCandidate);

        /**

         * Encodes XML-escaping characters found from aOriginal 

         * to XML Basic Entities. 

         *          Example: '&' -> '&'

         * Note! Function returns a copy of aOriginal descriptor,

         * even if not a single illegal, XML-escaping character

         * was encoded.

         * The returned pointer to heap allocated descriptor is

         * pushed to the cleanup stack.

         * @since Series60 3.0

         * @param   aOriginal   the string to be encoded.

         * @return  a buffer containing the encoded string. 

         *          Ownership is transferred to the caller.

         */

        IMPORT_C static HBufC8* EncodeHttpCharactersLC(const TDesC8& aOriginal);

        /**

         * Method to provide functionality for decoding HTTP characters into

         * XML escaping characters.

         * @since Series60 3.0

         * @param   aOriginal   the string to be decoded.

         * @param   aDecoded    the buffer that will contain the decoded string

         *                      on return. Caller has the ownership of this.

         *                      Will be similar as aOriginal if nothing was 

         *                      replaced.

         * @return ETrue if any XML escaping (some Basic Entity) 

         *                  character-sequence was decoded.

         */

        IMPORT_C static TBool DecodeHttpCharactersL(const TDesC8& aOriginal,

                                                HBufC8*& aDecoded);

        /**

         * Same as DecodeHttpCharactersL(), but the decoded string OR

         * exact copy of the aOriginal descriptor is returned and pushed

         * to cleanup stack.

         * @since Series60 3.0

         * @param   aOriginal   the string to be decoded.

         * @return buffer located in the cleanup stack containing the decoded 

         *          string

         */

        IMPORT_C static HBufC8* DecodeHttpCharactersLC(const TDesC8& aOriginal);

        /**

         * Helper function to get a prefix from a qualified name.

         * @since Series60 3.0

         * @param   aQName  the qualified name

         * @return the namespace prefix for the element, e.g. 'soap' for

         *      'soap:Body'. The returned pointer is empty if there is no prefix.

         */

        IMPORT_C static TPtrC8 NsPrefix(const TDesC8& aQName);

        /**

         *  Helper function to get a local name from a qualified name.

         *  @since Series60 3.0

         *  @param  aQName  the qualified name

         *  @return the local name for the element, e.g. 'Body' for

         *      'soap:Body'.

         */

        IMPORT_C static TPtrC8 LocalName(const TDesC8& aQName);

        /**

        * Removes certain attribute from given element. May also be used when

        * removing namespaces from the element.

        * @param aElement   Element from which attribute will be removed.

        * @param aAttrName  Attribute's local name

        * @return pointer to removed attribute, which ownership is transferred to

        * caller or NULL, if no matching attribute was found from this element. 

        */

        IMPORT_C static CSenBaseAttribute* RemoveAttributeL(CSenElement& aElement,

                                                            const TDesC8& aAttrName);

        /** 

        * Removes attribute from this element.

        * @param aElement       Element from which attribute will be removed.

        * @param apAttribute    is the attribute to be removed.

        * transferred to this element.

        * @return pointer to removed attribute, which ownership is transferred to

        * caller or NULL, if no matching attribute was found from this element. 

        */

        IMPORT_C static CSenBaseAttribute* RemoveAttributeL(CSenElement& aElement,

                                                            CSenBaseAttribute* apAttribute);

        /**

        * Adds an attribute into this element. Used also adding new namespaces

        * into the element.

        * @param aQName     Attribute's qualified name

        * @param aLocalName Attribute's local name

        * @param aValue     Attribute's value

        * @return value of the attribute as string (TDesC&)

        * Leave codes:  

        *       KErrSenInvalidCharacters if aLocalName or aQName contain illegal 

        *       characters.     

        *       KErrSenZeroLengthDescriptor if aLocalName or aQName is zero length.

        */

        IMPORT_C static const TDesC8& AddAttributeL(CSenElement& aElement,

                                                    const TDesC8& aQName,

                                                    const TDesC8& aLocalName,

                                                    const TDesC8& aValue);

        /**

        * Adds an attribute into this element. Used also adding new namespaces

        * into the element.

        * @param aLocalName Attribute's local name

        * @param aValue     Attribute's value

        * @return value of the attribute as string (TDesC&)

        * Leave codes:  

        *       KErrSenInvalidCharacters if aLocalName contains illegal characters.     

        *       KErrSenZeroLengthDescriptor if aAttrName is zero length, or

        *       if the local name part of it is zero length.

        */

        IMPORT_C static const TDesC8& AddAttributeL(CSenElement& aElement,

                                                    const TDesC8& aAttrName,

                                                    const TDesC8& aValue);

        /** 

        * Adds an attribute into this element.

        * @param apAttribute    Attribute to be added. Ownership is transferred

        *                       to this element.

        * @return attribute value as a string (TDesC8&)

        */

        IMPORT_C static const TDesC8& AddAttributeL(CSenElement& aElement,

                                                    CSenBaseAttribute* apAttribute);

    private:

        /**

        * C++ default constructor.

        */

        SenXmlUtils() { }

        /**

        * Prohibit copy constructor if not deriving from CBase.

        */

        SenXmlUtils( const SenXmlUtils& );

        /** 

        * Prohibit assignment operator if not deriving from CBase.

        */

        SenXmlUtils& operator=( const SenXmlUtils& );

        /**

        * Replaces the destination with the given values

        */

        static TBool ReplaceAll( TPtr8 aDestination, 

                                 const TDesC8& aFrom,

                                 const TDesC8& aTo );        

		/**

		* Finds the attribute with the given name

		*/

        static CSenBaseAttribute* FindAttrL( CSenElement& aElement,

                                             const TDesC8& aName );

    };

#endif // SEN_XML_UTILS_H

// End of File