I'm attempting to write a rudimentary MARC validator in ruby based on a short list of required and optional but desirable fields, partly as an exercise to write something in ruby, which I'm not terribly familiar with.
I've come up with what looks like valid ruby code to store my "optional" fields (and the script executes when this is enabled code):
Optional = ['006', '007', '010', '020', '022', {'040' => ['c']}, '041', ['050', '060', '082', '086', /09\d/], {/1\d\d/ => ['a']}, {'240' => ['a']}, '250', {'260' => ['a', 'b', 'c']}, {'300' => ['a']}, '490', /7[0-5]\d/, '830']
Based on my limited reading, this is technically feasible...but I'm not sure where to go from here. I'd like to iterate over the various fields in the record and if a field (or subfield if noted) is missing, write a warning to the screen:
sysnum = record['001']
record.fields.each do |field|
Optional.each do |optfield|
if field.tag =~ optfield
break
else
puts "#{sysnum} is missing #{field.tag}"
end
end
end
However, that won't work for all of my cases, since not all of the optfield values will be a string. Should I be using an if block to test for hashes? What about the regex values? Will =~ test true for when the right side isn't a regex (string =~ otherstring instead of string =~ regex)?
Am I barking up the wrong tree altogether here?
You probably want to use ===, which you can read as "kinda equals". It works for both strings and regexps as you would expect:
'100' === '100'
# true
/1\d\d/ === '100'
# true
For your arrays, you can use Regexp.union which turns an array of strings into a regexp that matches any of those strings.