From: "Sebastian (syepes)" <sebastian@...>
Date: 2008-12-11T19:26:29+09:00
Subject: Re: Problem parseing a XML - PullParser

Bob Hutchison wrote:
> Hi,
> 
> On 10-Dec-08, at 8:35 AM, Sebastian (syepes) wrote:
> 
>> Mmm, so is there a way to "parse* each line of the XML independently,
>> and is it posible with the PullParser library?
> 
> 
> Having written a pull parser, I'd have to say: No.
> 
> The parser is going to be looking for 'events', and it is going to
> want to deal with well-formedness issues if it is an actual xml parser.
> 
> What are you trying to do, maybe that's a better place to start.
> 
> Cheers,
> Bob
> 
> ----
> Bob Hutchison
> Recursive Design Inc.
> http://www.recursive.ca/
> weblog: http://www.recursive.ca/hutch


Ok, this is the problem i am trying to solve:
I need to parse a XML that comes from the stdout of a unix program, the 
program sends a xml* stream when it detects a change and the IO.popen 
stays open until the next change.

The real problem is that the function: ex_listener, processes the XML 
"line by line" because i can't detect a EOF from the IO.popen and it 
will always be waiting (open) for the next change "xml stream".


I have tried using "lines = ios.readlines", but it does not work because 
there's no EOF, is there some other way of doing this?

I would appreciate any suggestions on how to solve this problem.


*xml: Sent when a change is detected
---
<SChange>
  <Service>Testing:service</Service>
  <Status>Critical</Status>
  <Mode>Normal</Mode>
</SChange>

Ruby
---------
UNIX_PROG = "/bin/xml_stream"

def ex_connect
  ios = IO.popen(UNIX_PROG,"w+")
  ios.sync = true

  line = ios.gets
  if line =~ /xml/
    puts "INF: Connected OK (XML)"
    ios.puts "<Events>"
    return ios
  else
    puts "ERR: Cannot connect"
    exit 1
  end
end

def ex_listener(ios)
  while (line = ios.gets)
    line.chomp!
    if line =~ /<\/Events>/
      puts "INF: END of program"
      exit 0
    end

    puts "INF: #{line} - #{line.size}"
    *parse_line_of_xml(line)*
  end
end

ios = ex_connect
ex_listener(ios) # Processes the XML stream
---------


Regards,
-- 
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