Rails - Sep 2009 - libxml-ruby: How to handle XML::Parser::ParseError?

Code:

require "rubygems"
require "xml"

class TaskLoader
  class BadXML < RuntimeError
  end

  def load_tasks
    doc = XML::Parser.file( "qq.xml" ).parse
    # ... work with document ...
  rescue XML::Parser::ParseError, BadXML # this is line #40
    # ...
  end

end # TaskLoader

p TaskLoader.new.load_tasks # this is line #71

Output:

read_xml.rb:40:in `load_tasks'': uninitialized constant
LibXML::XML::Parser::ParseError (NameError)
	from read_xml.rb:71

Question: why does ruby interpret XML::Parser::ParseError in rescue-
clause as LibXML::XML::Parser::ParseError?
Thanks.

On Sep 4, 2:41 pm, adrianopol
<adriano...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> read_xml.rb:40:in `load_tasks'': uninitialized constant
> LibXML::XML::Parser::ParseError (NameError)
>         from read_xml.rb:71
>
> Question: why does ruby interpret XML::Parser::ParseError in rescue-
> clause as LibXML::XML::Parser::ParseError?
because the top level constant XML is LibXML::XML (check their
object_id )

Fred
> Thanks.

OK, so, how should I handle this exception?

On Sep 4, 6:12 pm, Frederick Cheung
<frederick.che...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> On Sep 4, 2:41 pm, adrianopol
<adriano...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
> > read_xml.rb:40:in `load_tasks'': uninitialized constant
> > LibXML::XML::Parser::ParseError (NameError)
> >         from read_xml.rb:71
>
> > Question: why does ruby interpret XML::Parser::ParseError in rescue-
> > clause as LibXML::XML::Parser::ParseError?
>
> because the top level constant XML is LibXML::XML (check their
> object_id )
>
> Fred
>
> > Thanks.

Documentation (http://libxml.rubyforge.org/rdoc/classes/LibXML/XML/
Parser.html#M000123, bottom of the page) says that
XML::Parser::ParseError should be thrown. I tried to raise it (trying
to parse bad xml-string) and the exception is really different:

    irb(main):005:0> XML::Parser.string(
"<foo></ba/r/></foo>").parse
    Fatal error: expected ''>'' at :1.
    Fatal error: Opening and ending tag mismatch: foo line 1 and ba
at :1.
    Fatal error: Extra content at the end of the document at :1.
    LibXML::XML::Error: Fatal error: Extra content at the end of the
document at :1.
        from (irb):5:in `parse''
        from (irb):5
        from (null):0


I think, i should handle LibXML::XML::Error instead. The problem is
solved.

On Sep 4, 6:18 pm, adrianopol
<adriano...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> OK, so, how should I handle this exception?
>
> On Sep 4, 6:12 pm, Frederick Cheung
<frederick.che...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> wrote:
>
> > On Sep 4, 2:41 pm, adrianopol
<adriano...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
> > > read_xml.rb:40:in `load_tasks'': uninitialized constant
> > > LibXML::XML::Parser::ParseError (NameError)
> > >         from read_xml.rb:71
>
> > > Question: why does ruby interpret XML::Parser::ParseError in
rescue-
> > > clause as LibXML::XML::Parser::ParseError?
>
> > because the top level constant XML is LibXML::XML (check their
> > object_id )
>
> > Fred
>
> > > Thanks.