export_define.marcout

DESCRIPTION--------------------------------------

MARCout is a high-level language for defining MARC bibliographic record
exports. It's currently developed for MUSICat album records.

MARCout describes the necessary prerequisites and desired fields in
a simple declarative form. The hope is that MARCout authoring and editing
should be within the grasp of bibliographers who are not programmers.

MARCout PROCESS CHAIN

    {MARCout export definition}
        |
         -->[MARCout parser]
                |
                 -->{export data structure}
                            |
                            |
    {source record (JSON)}   -->[                       |
        |                       |MARCout record exporter|                       |
         ---------------------->|                       ]
                                    |
                                     -->{exported record}
                                            |
                                             --> [MARCout text serializer]
                                            or
                                            |
                                             --> [MARCout ISO 2709 serializer]





KNOWN PARAMETERS---------------------------------

    collection_namespace

    collection_label

    collection_abbr

    collection_host_url



JSON EXTRACTED PROPERTIES------------------------

    album_id = album_json['album']['id']

    main_artist_name = album_json['album']['main_artist_name']

    artist_is_group = album_json['album']['artist_is_group'] ::DEFAULT ''

    album_title = album_json['album']['title']

    release_date = normalize_date(album_json['album']['release_date'])

    record_label = album_json['album']['record_label']

    submission_round = album_json['album']['round']

    album_tracks = album_json['album']['tracks'] ::DEFAULT []

    spoken_languages = album_json['album']['spoken_languages']

    genre = album_json['album']['genre']

    front_cover_art_link = album_json['album']['front_cover_art']



FUNCTIONS----------------------------------------

    biblio_name(main_artist_name)

    normalize_date(release_date)

    release_year(release_date)

    release_decade(release_date)

    render_track_duration(track_duration)

    pretty_comma_list(listexpr)

    total_play_length(album_tracks)

    compute_control_number(album_id, collection_abbr)



MARC FIELD TEMPLATES------------------------------------

LDR:
    # The ISO 2709 LDR for a MARC 21 record will look like this:
    # 000000000011111111112222    tens digit of position index
    # 012345678901234567890123    ones digit of position index
    # ........................    24 positions (dots are placeholders for spaces)
    # 00000.......00000.......    Numeric placeholders: runtime length/position
    # 00000.....2200000...4500    MARC 21 fixed values per specification
    # 00000....a2200000...4500    MARCout fixed value for Unicode character set. 
    #
    # This leaves the following code open for assignment. Any code
    # position that:
    #
    #   1. has no default (default is determined by prior consensus, and 
    #       is provided informationally here; editing it in this MARCout 
    #       export definition has no effect), and 
    #
    #   2. is not overridden by editing the OVERRIDE field in this
    #       export definition:
    #
    # will be replaced by a single space in the exported LDR.
    # 
    # Note that the LDR, which is an ISO 2709-specific artifact, will be
    # provided in ALL serializations.
    #
    # NOTES:
    #   1. In non-ISO 2709 serializations, the file arithmetic positions 00-04 
    #       and 12-16 will be filled with zeroes, since the file arithmetic is
    #       meaningless for other file types.
    #
    #   2. Ignoring the LDR is the responsibility of the party consuming the
    #       export.
    #
    BIBLIO CODES
        LDR POS: 05 - Record status # (default "n": New Record)
            OVERRIDE: 
        LDR POS: 06 - Type of record # (default "j": New Record)
            OVERRIDE: 
        LDR POS: 07 - Bibliographic level # (default "m": New Record)
            OVERRIDE: 
        LDR POS: 08 - Type of control
            OVERRIDE: 
        LDR POS: 17 - Encoding level # (default "1": Full Level, Material Not Encoded)
            OVERRIDE: 
        LDR POS: 18 - Descriptive cataloging form
            OVERRIDE: 
        LDR POS: 19 - Multipart resource record level
            OVERRIDE: 


FIELD: 001
    CONTENT: compute_control_number(album_id, collection_abbr)


FIELD: 003
    CONTENT: collection_label + ' MUSICat'


# example of commenting out a block of code
#FIELD: 003
#    SUBFIELD: a
#        collection_label + ' MUSICat'


FIELD: 100
# note that "EXPORT UNLESS" is a default: if the property is missing or screwed up,
# that counts as ("artist_is_group": false), so you DO export this field.
EXPORT UNLESS: artist_is_group IS TRUE     # This is the conjectural "artist_is_group" property
INDC1: 1
INDC2: blank
    SUBFIELD: a                         # subfield code on same line
        # it's OK to have a comment in between -- they get stripped out first
        biblio_name(main_artist_name)   # subfield value on VERY NEXT non-comment line


FIELD: 110
EXPORT WHEN: artist_is_group IS TRUE
INDC1: 2
INDC2: blank
    SUBFIELD: a
        main_artist_name + ' (Musical group)'


FIELD: 245
INDC1: 1
INDC2: 0
    SUBFIELD: a
        album_title
    SUBFIELD: c
        main_artist_name


FIELD: 260
INDC1: blank
INDC2: blank
    SUBFIELD: a
        '[Place of publication not indicated] :'
    SUBFIELD: b
        record_label
    SUBFIELD: c
        release_year(release_date)


FIELD: 300
INDC1: blank
INDC2: blank
    SUBFIELD: 1
        'online resource (1 audio file (' + total_play_length(album_tracks) + ')) ;'
    SUBFIELD: b
        'digital'


FIELD: 500
INDC1: blank
INDC2: blank
    SUBFIELD: a
        'MUSICat Submission Round: ' + submission_round


FIELD: 506
INDC1: blank
INDC2: blank
    SUBFIELD: a
        'Streaming available to Library patrons.'
    SUBFIELD: m
        collection_label + ' content provided by MUSICat'


FIELD: 511
INDC1: blank
INDC2: blank
    SUBFIELD: a
        'Performed by ' + main_artist_name


FIELD: 505
INDC1: 0
INDC2: 0
    FOR EACH: track in album_tracks
        # EACH-PREFIX:
        EACH-SUBFIELD: t
            track::title
        EACH-SUBFIELD: g
            render_duration(track::duration)
        EACH-SUFFIX: ' --'
        SORT BY: track::position


FIELD: 546
INDC1: blank
INDC2: blank
    SUBFIELD: a
        'Sung in ' + pretty_comma_list(spoken_languages)


FIELD: 650
INDC1: blank
INDC2: 0
    SUBFIELD: a
        genre
    SUBFIELD: y
        release_decade(release_date)


FIELD: 710
INDC1: 2
INDC2: blank
    SUBFIELD: a
        'Rabble, LLC'
    SUBFIELD: u
        'MUSICat'


# subfield 42
FIELD: 856
INDC1: 4
INDC2: 2
    SUBFIELD: z
        'Cover image'
    SUBFIELD: u
        front_cover_art_link


# subfield 40
FIELD: 856
INDC1: 4
INDC2: 0
    SUBFIELD: u
        collection_host_url + '/albums/' + album_id
    SUBFIELD: z
        'Click here to access this electronic item'