XML, WebService and Character Encoding issue

[Gonzalo Rubio]

I created a Ruby proxy for a FoxPro app that needs to fetch data from a
WebService (which returns it in XML) and read it in CSV format (for
which i use REXML parser and output the CSV by hand)
To do this the WebService returns me a Base64 encoded XML that i then
decode and process.

Everything works ok until you have non-standard characters in the XML
data (non 7-bit characters, i.e. Western European accented characters)
since the REXML parser dies complaining about a closing tag not found.
I looked for an entities processor or a character encoding converter in
the standard library and i coudn't find it.

I ended doing an ugly hack by feeding a Hash with the accented character
as the key, and the entity as the value, and then replacing back and
forth the returned data.
my function looks like this:

def iso2entities(str, inverse)
rep = Hash.new
rep['á'] = 'á'
# ... snipped code ...
rep['©'] = '©'

unless inverse
rep.each{|code, entity| str.gsub!(code, entity) }
else
rep.each{|code, entity| str.gsub!(entity, code) }
end
return str
end

It works, but feeding the Hash by hand is time consuming and code
obviously looks like an ugly work-around... is there a "ruby standard"
way to do it?