NAME
PICA::Writer - Write and count PICA+ records and fields
DESCRIPTION
This module contains a simple class to write PICA+ records and fields. Several output targets (file, GLOB, IO:Handle, string) and formats (XML, plain, normalized) are supported. The number of written records and fields is counted so you can also use the class as a simple counter.
SYNOPSIS
$writer = PICA::Writer->new( \*STDOUT );
$writer = PICA::Writer->new( "output.pica" );
$writer = PICA::Writer->new( \$string, format => 'xml' );
$writer = PICA::Writer->new( ); # no output
$writer->start(); # called implicitely by default
$writer->write( $record );
$writer->write( $field1, $field2, $field3 );
$writer->write( $comment, $record );
$writer->output( "output.xml" );
$writer->output( \*STDOUT, format => 'plain' );
print $writer->counter() . " records written\n";
print $writer->fields() . " fields written\n";
$writer->reset(); # reset counters
print $writer->status() == PICA::Writer::ENDED ? "open" : "ended";
$writer->end(); # essential to close end tags in XML and suchMETHODS
new ( [ $output ] [ format => $format ] [ %options ] )
Create a new writer. See the output method for possible parameters. The status of the new writer is set to PICA::Writer::NEW which is zero.
output ( [ $output ] [ format => $format ] [ %options ] )
Define the output handler for this writer. Record and field counters are not reset but the writer is ended with the end method if it had been started before. The output handler can be a filename, a GLOB, an IO:Handle object, a string reference, or undef. In addition you can specify the output format with the format parameter (plain or xml) and some options depending on the format, for instance 'pretty => 1'.
The status of the writer is set to PICA::Writer::NEW which is zero.
reset ( [ $output ] )
Reset the writer by setting record and field counters to zero and returning the writer object. Optionally you can define a new output handler, so the following two lines are equal:
$writer->output( $output )->reset();
$writer->reset( $output );The status of the writer will only be changed if you specify a new output handler.
write ( [ $comment | $record | $field ]* )
Write PICA::Field, PICA::Record objects, and comments (as strings) and record the writer object. The number of written records and fields is counted and can be queried with methods counter and fields.
$writer->write( $record );
$writer->write( @records );
$writer->write( "record number " . $writer->counter(), $record );
$writer->write( $field1, $field2 );Writing single fields or mixing records and fields may not be possible depending on the output format and output handler.
start ( [ %options ] )
Start writing and return the writer object. Depending on the format and output handler a header is written. Afterwards the status is set to PICA::Writer::STARTED. You can pass optional parameters depending on the format.
$writer->start( ); # default
$writer->start( xslt => 'mystylesheet.xsl' );
$writer->start( nsprefix => 'pica' );This method is implicitely called the first time you write to a PICA::Writer that is not in status PICA::Writer::STARTED..
end ( )
Finish writing. Depending on the format and output handler a footer is written (for instance an XML end tag) and the output handler is closed. Afterwards the status is set to PICA::Writer::ENDED. If the writer had not been started before, the start method is called first.
Ending or writing to an already ended writer will throw an error. You can restart an ended writer with the output method or with the start method.
status ( )
Return the status which can be PICA::Writer::NEW (0), PICA::Writer::STARTED, or PICA::Writer::ENDED.
counter ( )
Returns the number of written records.
fields ( )
Returns the number of written fields.
FUNCTIONS
xmlwriter ( %params )
Create a new XML::Writer instance and optionally write XML header and processing instruction. Relevant parameters include 'header' (boolean), 'xslt', NAMESPACES, PREFIX_MAP.
AUTHOR
Jakob Voss <jakob.voss@gbv.de>
LICENSE
Copyright (C) 2007-2009 by Verbundzentrale Goettingen (VZG) and Jakob Voss
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.