From: vasudevram <vasudevram@...>
Date: 2007-07-25T03:59:59+09:00
Subject: Re: Creating xml files: what are the right libraries to use?

On Jul 24, 3:34 am, "Kyle Schmitt" <kyleaschm...@gmail.com> wrote:
> When creating an xml document with ruby, what are currently the
> "right" libraries to use.
> I ask because there seem to be dozens in various states of
> completeness and maintenance...
>
> In this case I'd use to to create a large xml file, a little bit at a
> time (so I'd really rather it wasn't holding the whole blasted thing
> in memory)
>
> Thanks,
>           Kyle

Have you thought of generating the XML yourself via puts or print or
file_or_IO_object.write method calls? Unless you're pressed for time,
or have advanced requirements like being able to handle different
encodings, this might be the easiest way - since it would not depend
on any library. One possible drawback is that the code would be a bit
less readable, with all the calls, e.g.:

print "<person><name>#{person.name}</name></person>"

and so on, if you do it that way - i.e. write out all the XML output
in 'longhand'. But what I actually mean is to do it by writing some
simple methods for each kind of tag - for opening as well as closing
XML tags, as well as for text content and attributes. Something on the
lines of:

def start_element(element_name)
    print "<" + element_name + ">"
end

def end_element(element_name)
    print "</" + element_name + ">"
end

and so on. Then use them like this:

start_element("person")
start_element("name")
print person.name
end_element("name")
end_element("person")

You could optionally (preferable, really) add a trailing \n to the
output of each open/close element tag, to make the output more human-
readable.

If you really have special requirements, one idea is to check out the
book "Enterprise Integration with Ruby" from the Pragmatic Bookshelf,
which has some discussion on doing it both ways - rolling your own as
well as using some simple libraries.

Vasudev Ram
http://www.dancingbison.com
http://jugad.livejournal.co
http://sourceforge.net/projects/xtopdf