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<concept id="GUID-675D02F1-E7B1-4869-9213-8D0C2E0CC50D" xml:lang="en"><title>Adding,
Removing and Accessing Header Field Parts</title><prolog><metadata><keywords/></metadata></prolog><conbody>
<section id="GUID-F273A4FC-D2C7-45A2-A2CA-12D9B6C8531C"> <p>Header field parts are added by repeated invocation of the <xref href="GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9.dita#GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9/GUID-A8708AE6-8EAE-37C9-BAD2-87E4A7DCE266"><apiname>RHTTPHeaders::SetFieldL()</apiname></xref> method.
On the first invocation, when no field of that name exists in the header,
a new field is created with a single part. On subsequent invocations, additional
parts are added to the existing header field. </p> <p>This behaviour is consistent
with HTTP/1.1 in which: </p> <codeblock id="GUID-16F90813-AABE-5855-A7EB-6CB4C4D52225" xml:space="preserve">Accept: text/*, text/html</codeblock> <p>is
preferable to </p> <codeblock id="GUID-7290C356-D37B-5A79-9C11-470D500647CC" xml:space="preserve">Accept: text/* text/html</codeblock> <p>Although
the two are semantically equivalent, the API will not output the second variant
under any circumstance. </p> <p>When parts are added to a header field, they
are given an index number. The first part to be added has index 0, the second
is index 1, and so on. This index is necessary when identifying parts for
retrieval (using <xref href="GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9.dita#GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9/GUID-E89FA67E-7E0B-3C37-B920-B6E594A31BFE"><apiname>RHTTPHeaders::GetField()</apiname></xref>). </p> <p>To
remove a single header field part, <xref href="GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9.dita#GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9/GUID-656EF7AC-479E-3408-B00C-9FAE3022A37B"><apiname>RHTTPHeaders::RemoveFieldPart()</apiname></xref> is
used, specifying a part index. To remove a header field entirely, <xref href="GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9.dita#GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9/GUID-2C6BE5F2-E486-39E9-8594-2E5A5E936C1A"><apiname>RHTTPHeaders::RemoveField()</apiname></xref> is
used. </p> <p>Part values are accessed using <xref href="GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9.dita#GUID-54F9A87B-FE2F-3429-9793-0A24B83466B9/GUID-E89FA67E-7E0B-3C37-B920-B6E594A31BFE"><apiname>RHTTPHeaders::GetField()</apiname></xref>.
The client must supply a part index and an uninitialized <xref href="GUID-DEE8279A-3BEC-316F-97B8-6C49FEDBD5B3.dita"><apiname>THTTPHdrVal</apiname></xref>,
which will be filled by the method. This example, from <filepath>HTTPEXAMPLECLIENT</filepath>,
retrieves all response headers and prints their values: </p> <codeblock id="GUID-034F2800-1177-5E78-8253-134E5B2C2323" xml:space="preserve">void CHttpEventHandler::DumpRespHeadersL(RHTTPTransaction&amp; aTrans)
    {
    RHTTPResponse resp = aTrans.Response();
    RStringPool strP = aTrans.Session().StringPool();
    RHTTPHeaders hdr = resp.GetHeaderCollection();
    THTTPHdrFieldIter it = hdr.Fields();

    TBuf&lt;KMaxHeaderNameLen&gt;  fieldName16;
    TBuf&lt;KMaxHeaderValueLen&gt; fieldVal16;

    while (it.AtEnd() == EFalse)
        {
        RStringTokenF fieldName = it();
        RStringF fieldNameStr = strP.StringF(fieldName);
        THTTPHdrVal fieldVal;
        if (hdr.GetField(fieldNameStr,0,fieldVal) == KErrNone)
            {
            const TDesC8&amp; fieldNameDesC = fieldNameStr.DesC();
            fieldName16.Copy(fieldNameDesC.Left(KMaxHeaderNameLen));
            switch (fieldVal.Type())
                {
            case THTTPHdrVal::KTIntVal:
                iUtils.Test().Printf(_L("%S: %d\n"), &amp;fieldName16, fieldVal.Int());
                break;
            case THTTPHdrVal::KStrFVal:
                {
                RStringF fieldValStr = strP.StringF(fieldVal.StrF());
                const TDesC8&amp; fieldValDesC = fieldValStr.DesC();
                fieldVal16.Copy(fieldValDesC.Left(KMaxHeaderValueLen));
                iUtils.Test().Printf(_L("%S: %S\n"), &amp;fieldName16, &amp;fieldVal16);
                fieldValStr.Close();
                }
                break;
            case THTTPHdrVal::KStrVal:
                {
                RString fieldValStr = strP.String(fieldVal.Str());
                const TDesC8&amp; fieldValDesC = fieldValStr.DesC();
                fieldVal16.Copy(fieldValDesC.Left(KMaxHeaderValueLen));
                iUtils.Test().Printf(_L("%S: %S\n"), &amp;fieldName16, &amp;fieldVal16);
                fieldValStr.Close();
                }
                break;
            case THTTPHdrVal::KDateVal:
                {
                TDateTime date = fieldVal.DateTime();
                TBuf&lt;40&gt; dateTimeString;
                TTime t(date);
                t.FormatL(dateTimeString,KDateFormat);
                iUtils.Test().Printf(_L("%S: %S\n"), &amp;fieldName16, &amp;dateTimeString);
                } 
                break;
            default:
                iUtils.Test().Printf(_L("%S: &lt;unrecognised value type&gt;\n"), &amp;fieldName16);
                break;
                }
            ...
            }
        // Advance the iterator to get the next field
        ++it;
        }
     }</codeblock> <p>Note that in this example, only the first part of each
header field is displayed. </p> </section>
</conbody></concept>