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<concept id="GUID-0E8206E9-4F1D-5DF5-8A69-9B0831061CFF" xml:lang="en"><title>Escape
Encoding and Decoding</title><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>This tutorial describes the steps to escape encoding and decoding. </p>
<section><title>Introduction</title> <p>Reserved, unsafe and unreserved characters
present a possibility of being interpreted incorrectly when used in the URIs.
To avoid this, these characters must be escape encoded and decoded. </p> </section>
<section><title>Escape encoding </title><p>URI encoding of a character consists
of a "%" symbol, followed by two hexadecimal digits representing the octet
code. For example, Space = decimal code point 32 in the ISO-Latin set. 32
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
encodes the invalid and reserved characters in the data as escape triples.
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
to the above table) form the entire set of excluded data. </p> <p>The following
code fragment checks for the invalid and reserved characters in the authority
component of an URI and returns the string with these characters escape encoded.
For other modes as defined in <xref href="GUID-0B61C1D3-7DAB-3149-932F-1F96A84EDF42.dita"><apiname>TEscapeMode</apiname></xref>, refer to the
table in <xref href="GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49.dita#GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49/GUID-B5EB7F55-60AF-5703-96F6-0C42A3D433EE">Reservered
characters</xref> section. </p> <codeblock id="GUID-D0CBCEA3-59F2-50E0-AC4D-473FC5DF24E9" xml:space="preserve">HBufC16* encode = EscapeUtils::EscapeEncodeL(*decode, EscapeUtils::EEscapeAuth);
CleanupStack::PushL(encode);//encode contains %20%3C%3E%23%25%22%7B%7D%7C%5C%5E%60
......//use encode here
CleanupStack::PopAndDestroy(encode);
</codeblock> <p>Escape encoding is ideal during creation of URI from the components. </p> </section>
<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
decodes the data. This code escape decodes the data '<codeph>%20%3C%3E%23%25%22%7B%7D%7C%5C%5E%60</codeph>'
to '<codeph><>#%\"{}|\\^</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
HBufC16* decode = EscapeUtils::EscapeDecodeL(KEscapeEncoded); //contains <>#%\"{}|\\^`
CleanupStack::PushL(decode);
...........................
CleanupStack::PopAndDestroy(decode);
</codeblock> <p>The URI must be split into its components before
the escaped characters within the components are safely decoded. </p></section>
</conbody><related-links>
<link href="GUID-795B41AF-FBEA-56CE-AE20-EF17BE754723.dita"><linktext>HTTP Utilities
Library Overview</linktext></link>
<link href="GUID-853BFDC0-1993-5EFC-AA68-C9EA496EEF3F.dita"><linktext>Converting
between Unicode and Utf8</linktext></link>
<link href="GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49.dita"><linktext>Reserved
and unreserved characters</linktext></link>
</related-links></concept>