Output XML buffer?

[Jan Danielsson]

Hello all,

I'm using ElementTree to create an XHTML page (mod_python, blah,
blah, blah). When I use ElementTree.tostring(root) to create a buffer
which I want to return to the client, it doesn't include the XML prolog
(obvisouly, since tostring is merely traversing the tree from the node I
supply to it.

I could simply prefix the tostring output with a string containing my
"<?xml ...>" schtick. But let's, for the sake of argument, say that I
trust a library more to generate it for me, rather than hand coding it
myself (not entirely true, but let's assume that is the case).

--
Kind regards,
Jan Danielsson

[=?ISO-8859-1?Q?=22Martin_v=2E_L=F6wis=22?=]

I'm using ElementTree to create an XHTML page (mod_python, blah,

blah, blah). When I use ElementTree.tostring(root) to create a buffer
which I want to return to the client, it doesn't include the XML prolog
(obvisouly, since tostring is merely traversing the tree from the node I
supply to it.

Not at all obvious. It considered writing an XML prolog, but then
decided against it because the output encoding was UTF-8 or ASCII,
in which case the prolog can be safely omitted by the XML
recommendation.

I could simply prefix the tostring output with a string containing my
"<?xml ...>" schtick. But let's, for the sake of argument, say that I
trust a library more to generate it for me, rather than hand coding it
myself (not entirely true, but let's assume that is the case).

Did you mean to include some question? If you meant to ask "Can I make
it write an XML prolog, and if so, how?", then the anwser is:
use an output encoding different from utf-8 or us-ascii.

Regards,
Martin

[Stefan Behnel]

Jan Danielsson wrote:

I'm using ElementTree to create an XHTML page (mod_python, blah,
blah, blah). When I use ElementTree.tostring(root) to create a buffer
which I want to return to the client, it doesn't include the XML prolog

As Martin told you, this is spec-compliant behaviour. Still, ElementTree 1.3
is expected to add a keyword argument "xml_declaration" in tostring() that
will let you override the default behaviour. lxml.etree already implements
that, BTW.

http://codespeak.net/lxml

I could simply prefix the tostring output with a string containing my
"<?xml ...>" schtick. But let's, for the sake of argument, say that I
trust a library more to generate it for me, rather than hand coding it
myself (not entirely true, but let's assume that is the case).

Some people propose just that if you really *want* a declaration. No need to
have it, though, as ET will create well-formed XML anyway.

Stefan

[Jan Danielsson]

Stefan Behnel wrote:
[---]

lxml.etree already implements that, BTW.

http://codespeak.net/lxml

Ok, thanks. I'll take a look at it.

[---]

Some people propose just that if you really *want* a declaration. No need to
have it, though, as ET will create well-formed XML anyway.

Yeah, I checked the specs, and found a '?' there (but not where I
expected it to be). I just checked the first mention of the "header",
and didn't see it marked as optional.

However, I want it to be there, simply because it feels better. I'll
check lxml out.

--
Kind regards,
Jan Danielsson