1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-0E8206E9-4F1D-5DF5-8A69-9B0831061CFF" xml:lang="en"><title>Escape

    13 Encoding and Decoding</title><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>This tutorial describes the steps to escape encoding and decoding. </p>

    15 <section><title>Introduction</title> <p>Reserved, unsafe and unreserved characters

    16 present a possibility of being interpreted incorrectly when used in the URIs.

    17 To avoid this, these characters must be escape encoded and decoded. </p> </section>

    18 <section><title>Escape encoding </title><p>URI encoding of a character consists

    19 of a "%" symbol, followed by two hexadecimal digits representing the octet

    20 code. For example, Space = decimal code point 32 in the ISO-Latin set. 32

    21 decimal = 20 in hexadecimal. The URI encoded representation will be "%20" </p> <p> <xref href="GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51.dita#GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51/GUID-26C9B121-B619-33EF-98A3-E65787C3A9BF"><apiname>EscapeUtils::EscapeEncodeL()</apiname></xref> escape

    22 encodes the invalid and reserved characters in the data as escape triples.

    23 The reserved characters and the set of excluded characters specified by <xref href="http://www.ietf.org/rfc/rfc2396.txt" scope="external">RFC 2396</xref> (refer

    24 to the above table) form the entire set of excluded data. </p> <p>The following

    25 code fragment checks for the invalid and reserved characters in the authority

    26 component of an URI and returns the string with these characters escape encoded.

    27 For other modes as defined in <xref href="GUID-0B61C1D3-7DAB-3149-932F-1F96A84EDF42.dita"><apiname>TEscapeMode</apiname></xref>, refer to the

    28 table in <xref href="GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49.dita#GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49/GUID-B5EB7F55-60AF-5703-96F6-0C42A3D433EE">Reservered

    29 characters</xref> section. </p> <codeblock id="GUID-D0CBCEA3-59F2-50E0-AC4D-473FC5DF24E9" xml:space="preserve">HBufC16* encode = EscapeUtils::EscapeEncodeL(*decode,  EscapeUtils::EEscapeAuth);

    30 CleanupStack::PushL(encode);//encode contains %20%3C%3E%23%25%22%7B%7D%7C%5C%5E%60

    31 

    32 ......//use encode here

    33 

    34 CleanupStack::PopAndDestroy(encode);

    35 </codeblock> <p>Escape encoding is ideal during creation of URI from the components. </p> </section>

    36 <section><title>Escape decoding </title><p> <xref href="GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51.dita#GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51/GUID-B4149EF0-0E1D-3F80-9974-165DF17105E9"><apiname>EscapeUtils::EscapeDecodeL()</apiname></xref> escape

    37 decodes the data. This code escape decodes the data '<codeph>%20%3C%3E%23%25%22%7B%7D%7C%5C%5E%60</codeph>'

    38 to '<codeph>&lt;&gt;#%\"{}|\\^</codeph>'. </p> <codeblock id="GUID-F0A7F46E-F5DF-52CE-8334-AD7789208F97" xml:space="preserve">_LIT(KEscapeEncoded, %20%3C%3E%23%25%22%7B%7D%7C%5C%5E%60);        //data to decode

    39 HBufC16* decode = EscapeUtils::EscapeDecodeL(KEscapeEncoded); //contains <>#%\"{}|\\^`

    40 CleanupStack::PushL(decode);

    41 ...........................

    42 CleanupStack::PopAndDestroy(decode);

    43           </codeblock> <p>The URI must be split into its components before

    44 the escaped characters within the components are safely decoded. </p></section>

    45 </conbody><related-links>

    46 <link href="GUID-795B41AF-FBEA-56CE-AE20-EF17BE754723.dita"><linktext>HTTP Utilities

    47 Library Overview</linktext></link>

    48 <link href="GUID-853BFDC0-1993-5EFC-AA68-C9EA496EEF3F.dita"><linktext>Converting

    49 between Unicode and Utf8</linktext></link>

    50 <link href="GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49.dita"><linktext>Reserved

    51 and unreserved characters</linktext></link>

    52 </related-links></concept>