FlatFile::DataStore::Preamble - Perl module that implements a flatfile datastore preamble class.
use FlatFile::DataStore::Preamble; my $preamble = FlatFile::DataStore::Preamble->new( { datastore => $ds, # FlatFile::DataStore object indicator => $indicator, # single-character crud flag transind => $transind, # single-character crud flag date => $date, # pre-formatted date transnum => $transint, # transaction number (integer) keynum => $keynum, # record sequence number (integer) reclen => $reclen, # record length (integer) thisfnum => $fnum, # file number (in base format) thisseek => $datapos, # seek position (integer) prevfnum => $prevfnum, # ditto these ... prevseek => $prevseek, nextfnum => $nextfnum, nextseek => $nextseek, user => $user_data, # pre-formatted user-defined data } ); my $string = $preamble->string(); my $clone = FlatFile::DataStore::Preamble->new( { datastore => $ds, string => $string } );
FlatFile::DataStore::Preamble - Perl module that implements a flatfile datastore preamble class. This class defines objects used by FlatFile::DataStore::Record and FlatFile::DataStore. You will probably not ever call new() yourself, but you might call some of the accessors either directly or via a FF::DS::Record object;
A "preamble" is a string of fixed-length fields that precedes every record in a FlatFile::DataStore data file. In addition, this string constitutes the entry in the datastore key file for each current record.
FlatFile::DataStore::Preamble version 1.03
Constructs a new FlatFile::DataStore::Preamble object.
The parm $parms is a hash reference containing key/value pairs to populate the preamble string. If there is a $parms->{'string'} value, it will be parsed into fields and the resulting key/value pairs will replace the $parms hash reference.
$parms
$parms->{'string'}
The following methods set and return their respective attribute values if $value is given. Otherwise, they just return the value.
$value
$preamble->string( $value ); # full preamble string $preamble->indicator( $value ); # single-character crud indicator $preamble->transind( $value ); # single-character crud indicator $preamble->date( $value ); # date as YYYY-MM-DD (hh:mm:ss) $preamble->transnum( $value ); # transaction number (integer) $preamble->keynum( $value ); # record sequence number (integer) $preamble->reclen( $value ); # record length (integer) $preamble->thisfnum( $value ); # file number (in base format) $preamble->thisseek( $value ); # seek position (integer) $preamble->prevfnum( $value ); # ditto these ... $preamble->prevseek( $value ); # $preamble->nextfnum( $value ); # $preamble->nextseek( $value ); # $preamble->user( $value ); # pre-formatted user-defined data $preamble->crud( $value ); # hash ref of all crud indicators
Note: the class code uses these accessors to set values in the object as it is assembling the preamble string in new(). Unless you have a really good reason, you should not set these values yourself (outside of a call to new()). For example: setting the date with date() will not change the date in the string attribute.
string
In other words, even though these are read/write accessors, you should only use them for reading.
These methods return true if the indicator matches the value implied by the method name, e.g.,
print "Deleted!" if $preamble->is_deleted();
Brad Baxter, <bbaxter@cpan.org>
Copyright (C) 2011 by Brad Baxter
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.
To install FlatFile::DataStore, copy and paste the appropriate command in to your terminal.
cpanm
cpanm FlatFile::DataStore
CPAN shell
perl -MCPAN -e shell install FlatFile::DataStore
For more information on module installation, please visit the detailed CPAN module installation guide.