Replacing a text in XML.

[bendon]

Hello Team,

I would like to replace the text in <subfield code="0"> in datafield 650 below.

<datafield tag="650" ind1=" " ind2="7">
<subfield code="a">Sciences</subfield>
<subfield code="x">Philosophie.</subfield>
<subfield code="2">ram.</subfield>
<subfield code="0">(OSt)16</subfield>

I have my Script down here.

use strict;
use warnings;
use XML::Twig;
use Data::Dumper;

my $xml = <<XML;
<?xml version="1.0" encoding="UTF-8"?>
<collection
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.loc.gov/MARC21/slim http://www.loc.gov/
+standards/marcxml/schema/MARC21slim.xsd"
xmlns="http://www.loc.gov/MARC21/slim">

<record>
<leader>01376cam a2200349 4500</leader>
<controlfield tag="001">2 </controlfield>
<controlfield tag="003">OCoLC</controlfield>
<controlfield tag="005">20060313170419.0</controlfield>
<controlfield tag="008">690410s1963 laua b 000 0 eng </controlfield>
<datafield tag="010" ind1=" " ind2=" ">
<subfield code="a"> 63022268</subfield>
</datafield>
<datafield tag="019" ind1=" " ind2=" ">
<subfield code="a">9772597</subfield>
</datafield>
<datafield tag="029" ind1="1" ind2=" ">
<subfield code="a">NLGGC</subfield>
<subfield code="b">861755170</subfield>
</datafield>
<datafield tag="035" ind1=" " ind2=" ">
<subfield code="a">(OCoLC)2</subfield>
<subfield code="z">(OCoLC)9772597</subfield>
</datafield>
<datafield tag="040" ind1=" " ind2=" ">
<subfield code="a">DLC</subfield>
<subfield code="c">DLC</subfield>
<subfield code="d">OCLCQ</subfield>
<subfield code="d">TSE</subfield>
<subfield code="d">OCL</subfield>
</datafield>
<datafield tag="043" ind1=" " ind2=" ">
<subfield code="a">n-us-la</subfield>
</datafield>
<datafield tag="049" ind1=" " ind2=" ">
<subfield code="a">OCLC</subfield>
</datafield>
<datafield tag="050" ind1="0" ind2="0">
<subfield code="a">GB475.L6</subfield>
<subfield code="b">M6</subfield>
</datafield>
<datafield tag="082" ind1=" " ind2="4">
<subfield code="a">589.3</subfield>
</datafield>
<datafield tag="100" ind1="1" ind2=" ">
<subfield code="a">Morgan, James P.</subfield>
<subfield code="q">(James Plummer),</subfield>
<subfield code="d">1919-</subfield>
<subfield code="0">(OSt)873</subfield>
</datafield>
<datafield tag="245" ind1="1" ind2="0">
<subfield code="a">Mudlumps at the mouth of South Pass, Mississippi Ri
+ver;</subfield>
<subfield code="b">sedimentology, paleontology, structure, origin, and
+ relation to deltaic processes,</subfield>
<subfield code="c">by James P. Morgan, James M. Coleman and Sherwood M
+. Gagliano. Including appendices by R.D. Adams ... et al..</subfield>
</datafield>
<datafield tag="260" ind1=" " ind2=" ">
<subfield code="a">Baton Rouge,</subfield>
<subfield code="b">Louisiana State University Press,</subfield>
<subfield code="c">1963.</subfield>
</datafield>
<datafield tag="300" ind1=" " ind2=" ">
<subfield code="a">xvi, 190 p.</subfield>
<subfield code="b">illus.</subfield>
<subfield code="c">28 cm.</subfield>
</datafield>
<datafield tag="440" ind1=" " ind2="0">
<subfield code="a">Louisiana State University studies.</subfield>
<subfield code="p">Coastal studies series ;</subfield>
<subfield code="v">no. 10.</subfield>
<subfield code="0">(OSt)13</subfield>
</datafield>
<datafield tag="504" ind1=" " ind2=" ">
<subfield code="a">Bibliography: p. 183-190.</subfield>
</datafield>
<datafield tag="650" ind1=" " ind2="0">
<subfield code="a">Mud lumps</subfield>
<subfield code="z">Louisiana</subfield>
<subfield code="z">Mississippi River Delta.</subfield>
<subfield code="0">(OSt)14</subfield>
</datafield>
<datafield tag="650" ind1=" " ind2="0">
<subfield code="a">Sediments (Geology)</subfield>
<subfield code="z">Louisiana.</subfield>
<subfield code="0">(OSt)15</subfield>
</datafield>
<datafield tag="650" ind1=" " ind2="7">
<subfield code="a">Sciences</subfield>
<subfield code="x">Philosophie.</subfield>
<subfield code="2">ram.</subfield>
<subfield code="0">(OSt)16</subfield>
</datafield>
<datafield tag="700" ind1="1" ind2=" ">
<subfield code="a">Coleman, James M.,</subfield>
<subfield code="e">joint author.</subfield>
<subfield code="0">(OSt)17</subfield>
</datafield>
<datafield tag="700" ind1="1" ind2=" ">
<subfield code="a">Gagliano, Sherwood M.,</subfield>
<subfield code="e">joint author.</subfield>
<subfield code="0">(OSt)18</subfield>
</datafield>
<datafield tag="994" ind1=" " ind2=" ">
<subfield code="a">02</subfield>
<subfield code="b">OCL</subfield>
</datafield>
<datafield tag="945" ind1=" " ind2=" ">
<subfield code="a">GB475.L6 M6</subfield>
</datafield>
<datafield tag="999" ind1=" " ind2=" ">
<subfield code="c">1</subfield>
<subfield code="d">1</subfield>
</datafield>
</record>

</collection>

XML

my $twig = XML::Twig->new (
twig_roots => {href => \&editHref,},
twig_print_outside_roots => 1,
);

$twig->parse ($xml);
$twig->flush;

sub editHref {
my ($twig, $href) = @_;
my $text = $href->text ();
my $orig = "(OSt)16";
$text =~ s/\.$orig$/(OSt)20/;
$href->set_text ($text);
$href->print ();
}

[toolic]

I can see 2 problems. Your XML does not have an element named "href". You need to change elements named "subfield". Your regex is incorrect:

my $twig = XML::Twig->new(
    twig_handlers   => { subfield => \&editHref, },
    pretty_print    => 'indented',
);

$twig->parse($xml);
$twig->print;

sub editHref {
    my ( $twig, $href ) = @_;
    my $text = $href->text();
    my $orig = "(OSt)16";
    $text =~ s/\Q$orig/(OSt)20/;
    $href->set_text($text);
}

Or, just avoid the regex...

sub editHref {
    my ( $twig, $href ) = @_;
    my $text = $href->text();
    $href->set_text('(OSt)20') if $text eq '(OSt)16';
}

• Please use code tags: Writeup Formatting Tips

[bendon]

Thanks for the reply, Also I have another question to ask, If I want to search through the same XML file for this subfield. <subfield code="0">(OSt)18</subfield> from the database how do I go by it? Thanks.

[choroba]

You callback is never called, as there is no <href> element anywhere in your xml. You probably meant

    twig_roots => { 'subfield[@code="0"]' => \&editHref},