[Ocaml-pxp-users] Sending NUL chars in documents with PXP

[Gerd Stolpmann]

Am Montag, den 23.05.2005, 20:33 +0100 schrieb Richard Jones:
> How do I send an XML document containing an ASCII NUL ('\000') char?

Easy answer: This is not possible. XML documents must not contain
control characters other than CR, LF, and TAB.

I don't remember the details, but there is definitely a way of encoding
binary SOAP data (part of the SOAP protocol, not part of XML).

Gerd

> 
> I have the test program (attached below), which creates a document
> which looks like this:
> 
> $ ./nullchar | hexdump -c
> 0000000   <   t   e   s   t  \n   >  \0   <   /   t   e   s   t  \n   >
> 
> However when the remote SOAP server receives documents like this, it
> gives me the following error, where the error position is the position
> of the NUL char.
> 
> Application failed during request deserialization: not well-formed
> (invalid token) at line 10, column 1, byte 338 at
> /usr/lib/perl5/XML/Parser.pm line 187
> 
> This leads me to believe that PXP ought to be escaping the NUL char in
> some manner, but my knowledge of XML isn't good enough to know how to
> do this.  The upshot is that I can't send these sorts of strings or
> characters to a SOAP server.
> 
> Rich.
> 
> ----------------------------------------------------------------------
> (* Compile: ocamlc -I +pcre -I +netstring -I +pxp-lex-iso88591 -I +pxp-engine unix.cma pcre.cma netstring.cma pxp_engine.cma pxp_lex_iso88591.cma pxp_lex_link_iso88591.cmo nullchar.ml -o nullchar *)
> 
> let dtd =
>   let collect_warnings = Pxp_types.default_config.Pxp_types.warner in
>   let rep_encoding = Pxp_types.default_config.Pxp_types.encoding in
>   let dtd = new Pxp_dtd.dtd collect_warnings rep_encoding in
>   dtd#allow_arbitrary;
>   dtd
> 
> let spec =
>   let default_element_exemplar = new Pxp_document.element_impl
>     Pxp_tree_parser.default_extension in
>   let data_exemplar = new Pxp_document.data_impl
>     Pxp_tree_parser.default_extension in
>   Pxp_document.make_spec_from_alist ~data_exemplar
>     ~default_element_exemplar ~element_alist:[] ()
> 
> let () =
>   let node = Pxp_document.create_element_node spec dtd "test" [] in
>   let data = Pxp_document.create_data_node spec dtd "\000" in
>   node#set_nodes [data];
>   node#write (`Out_channel stdout) `Enc_utf8
> 
> 
-- 
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Gerd Stolpmann * Viktoriastr. 45 * 64293 Darmstadt * Germany 
gerd at gerd-stolpmann.de          http://www.gerd-stolpmann.de
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