Re: [libxml++] ISO-8859-2 enocdings

[Jonathan Wakely <cow compsoc man ac uk>]

On Tue, Dec 02, 2003 at 04:55:07PM +0100, Rainer Stransky wrote:

> I use libxml++ in a application dealing with iso-8859-2.
> 
> When creating a xmlpp::Document including special characaters (valid within 
> iso8859-2) the method-call document.write_to_string("iso-8859-2") (see code 
> below) puts a error message to stdout:
>   output conversion failed due to conv error
>   Bytes: 0xB5 0x72 0x61 0x69
> 
> and the resulting xml-string is corrupted (truncated at the postion of the 
> special character (Dec 174)
> 
> What is the problem ? Do i use libxml++ in a wrong manner ?

I can't tell from your code snippet, but I suspect the problem is that
you added ISO-8859-2 characters to the xmlpp::Document (using
set_child_content() or similar).

libxml2 (and therefore libxml++) uses UTF-8 as its internal encoding, so
any data you read from or write to an xmlDoc (or xmlpp::Document) must
be in UTF-8.

If you do this:

xmlNode->set_child_content("£££");
// ...
theRequest = document.write_to_string("iso-8859-2");

Then libxml will try to convert the xmlDoc structure from UTF-8 to
ISO-88590-2, but the "£££" data is not valid in UTF-8, so the conversion
fails.

When you add data to the document the data *must* be encoded in UTF-8.

When libxml outputs the doc it will be in the requested encoding.

Hope that helps,

jon


> code fragment:
> ------------------------------------------------------------
> xmlpp::Document document;
> xmlpp::Element* xmlPNode = 
> document.create_root_node(theCommand+XML_CM_REQUEST);
> 
> xmlPNode->add_attribute(XML_MA_XMLNS, XML_NAMESPACE_VALUE);
> xmlNode = xmlPNode->add_child(XML_NN_TASK);
> xmlNode->set_child_content(getHeaderAttr(OH_TASK_ID));
> xmlNode->add_attribute(XML_MA_NAMESPACE, ourNamespace);
> xmlNode->add_attribute(XML_MA_VERSION, ourVersion);
>  
> theRequest = document.write_to_string("iso-8859-2");
> 
> 
> 
> -- 
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