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I'm trying to make SOAP calls to a third-party web service which expects the data sent in UTF-8 encoding. I'm using 12.0.1.4314 with the default charset "windows-1252" and NCHAR charset "UTF-8".

For simple SOAP parameters (say UUIDs), that works when declaring the parameters as nvarchar types, such as

create function WSF_GetRequestStatus(ReqId nvarchar(36))
    returns xml
    url 'http://...'
    type 'SOAP:DOC'
    set 'SOAP(OP=GetRequestStatusRequest)'
    header 'SOAPAction:"urn:GetRequestStatus"'
    namespace 'http://...'
    SET 'SOAP(VERSION=1.1)';

This results in a request with the desired header

Content-Type: text/xml; charset=utf-8

instead of the default

Content-Type: text/xml; charset=windows-1252

I think this is explained here in the docs although that doc topic seems to refer to web service procedures:

When one or more parameters are of type NCHAR, NVARCHAR, LONG NVARCHAR, or NTEXT then the response output is in UTF8.

However, other SOAP calls require XML parameters. These XML documents are already available as UTF-8 encoded files, so I load them via xp_read_file and access them via a variable of datatype XML, too.

Therefore I have tried to use a SOAP function with a simple XML datatype, such as

create function WSF_StartRequest(ReqData xml)
    returns xml
    url 'http://...'
    type 'SOAP:DOC'
    ...

However, then the request tells to use the unfitting "windows-1252" charset, and so the SOPA request is rejected.

When testing with a different tool (SoapUI), the same request is described with charset utf-8 and succeeds.

Question: How can I force SA to declare the request with the desired charset?

Accepted Answer

FWIW, as a workaround, I took a different approach (comparable to the sample from the doc topic "Variables supplied in SOAP envelopes") and used a XML variable to build the whole SOAP envelope and thereby concatenated the values of the existing XML documents. Then I put the whole xml as parameter for a function with the following declaration:

create function WSF_StartRequest(XmlPayload long nvarchar)
    returns xml
    url 'http://...'
    type 'HTTP:POST:text/xml'
    header 'SOAPAction:"urn:StartRequest"'
    set 'HTTP(VERSION=1.1)';

This seems to work.

UPDATE: However, when doing so, in case the actual parameter is using one of the CHAR/VARCHAR/LONG VARCHAR/XML data types and the database charset is not UTF-8 but a typical one-byte-charset (Windows1252 in my case), then the actual parameter MUST be in that charset, too, because it will be converted to UTF-8 when supplied to the web client function.

I.e. if the original XML contents is already in UTF-8, you will need to re-convert it to the database charset, as with

set xmlData = csconvert(xmlData, 'char_charset', 'nchar_charset');

before you use that to construct the "xmlPayload" and use the latter with the web client function.

That is explained here in the docs:

When one or more parameters are of type NCHAR, NVARCHAR, LONG NVARCHAR, or NTEXT then the response output is in UTF8. If the client database uses the UTF-8 character encoding, there is no change in behavior (since NCHAR and CHAR data types are the same). However, if the database does not use the UTF-8 character encoding, then all parameters that are not an NCHAR data type are converted to UTF8. The value of the XML declaration encoding and Content-Type HTTP header will correspond to the character encoding used.

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How to influence the charset of a SOAP web client function with XML parameters?

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