NAME

       Catmandu::Fix::Bind::marc_each - a binder that loops over MARC fields

SYNOPSIS

           # Only add the 720 field to the authors when the $e subfield contains a 'promotor'
           do marc_each()
               if marc_match("720e","promotor")
                   marc_map("720ab",authors.$append)
               end
           end

           # Delete all the 500 fields
           do marc_each()
               if marc_has("500")
                   reject()
               end
           end

DESCRIPTION

       The marc_each binder will iterate over each individual MARC field and execute the fixes on
       each individual field.

       When a MARC record contains:

           500  $aTest
           500  $aTest2$eskip
           500  $aTest3

       then the Fix bellow will copy all 500 fields to note field, except for 500 fields with a
       subfield $e equal to "skip".

           do marc_each()
               unless marc_match("500e",skip)
                   marc_map("500",note.$append)
               end
           end

       The result will be:

           note: [Test,Test3]

CONFIGURATION

   var
       Optional loop variable which contains a HASH containing MARC field information with the
       following fields:

           tag        - The names of the MARC field
           ind1       - The value of the first indicator
           ind2       - The value of the second indicator
           subfields  - An array of subfield items. Each subfield item is a
                        hash of the subfield code and subfield value

       Given the MARC field:

           500[1, ] $aTest$bRest

       the loop variable will contain:

           tag: 500
           ind1: 1
           ind2: ' '
           subfields:
               - a : Test
               - b : Rest

       The loop variables can be used to have extra control over the processing of the MARC
       fields.

           do marc_each(var:this)
             # Set the indicator1 of all MARC 500 field to the value "3"
             if all_match(this.tag,500)
               set_field(tag.ind1,3)
               # Store the result in the MARC file
               marc_remove(500)
               marc_paste(this)
             end
           end

SEE ALSO

       Catmandu::Fix::Bind