http://qs1969.pair.com?node_id=11138619

szpt9m has asked for the wisdom of the Perl Monks concerning the following question:

Hello, I need a way to search and find some tags and values in my input xml and if that exist, i want to create a new xml file based on that. For example my input file looks something as below 
 
<?xml version="1.0" encoding="UTF-8"?>
<TestCode version="10.0">
    <TestCategory name="SmokeTest">
        <Test name="CheckType_123"  type="String">
            <Test_description>No description available for this Test <
+/Test_description>
            <context name="Testing">
                <value>ABC</value>
                <value>XYZ</value>
            </context>
        </Test>
        <Test name="CheckType_PQR"  type="String">
            <Test_description>No description available for this Test</
+Test_description>
            <context name="SmokeTest">
                <value>ABC</value>
            </context>
        </Test>
        <Test name="ValueAdded_123"  type="String">
            <Test_description>No description available for this Test</
+Test_description>
            <context name="Testing">
                <value>ABC</value>
                <value>XYZ</value>
            </context>
        </Test>
    </TestCategory>
</TestCode>

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From the above input xml file, I need to check if i have tag <Test name=CheckType_* and if yes, i need to check if i have context/vlaue = XYZ. If exist i need to take the whole <Test ...> </Test> tag and put it in a new xml file. So from the above xml, the output what i need is: 
 
<?xml version="1.0" encoding="UTF-8"?>
<TestCode version="10.0">
    <TestCategory name="SmokeTest">
        <Test name="CheckType_123"  type="String">
            <Test_description>No description available for this Test</
+Test_description>
            <context name="Testing">
                <value>ABC</value>
                <value>XYZ</value>
            </context>
        </Test>
    </TestCategory>
</TestCode>

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because from my input xml, the second Test tag has no value XYZ and 3rd Test tag has no name starting with CheckType_*. Can you help me with this?

Replies are listed 'Best First'.
Re: xml to xml converter
by haukex (Archbishop) on Nov 09, 2021 at 14:39 UTC

    Although my go-to XML module is XML::LibXML, XML::Twig is useful for filtering XML files. The following produces your expected output for the given input:

    use warnings;
use strict;
use XML::Twig;
use XML::XPath;  # for findnodes

my $filename = 'foo.xml';
XML::Twig->new(
    twig_print_outside_roots => 1,
    keep_spaces => 1,
    twig_roots => {
        '/TestCode/TestCategory/Test' => sub {
            my ($t, $elt) = @_;
            if ( $elt->{att}{name} =~ /^CheckType_/ ) {
                my @values = $elt->findnodes('./context/value');
                # could theoretically also use XPath for the following
                if ( grep { $_->text =~ /XYZ/ } @values )
                    { $t->flush }
                else { $t->purge }
            }
            else { $t->purge }
        },
    },
)->parsefile($filename);

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[reply]
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      Thank you for quick response but i get an error Can't locate XML/Twig.pm in @INC when running this. How can i install in module in Windows?
[reply]
        Thank you for quick response but i get an error Can't locate XML/Twig.pm in @INC when running this. How can i install in module in Windows?

        The same way you would install any other module. In Strawberry Perl, cpanm XML::Twig XML::XPath works for me.

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Re: xml to xml converter
by choroba (Cardinal) on Nov 09, 2021 at 16:30 UTC
    This is how you can do it in XML::XSH2, a wrapper around XML::LibXML. You can experiment with the code in its xsh shell interactively. 
    my $out := create "TestCode" ;
set $out/TestCode/@version "10.0" ;
set $out/TestCode/TestCategory/@name "SmokeTest" ;

open file.xml ;
cp //Test[starts-with(@name, "CheckType_")][context/value = "XYZ"]
    into $out/TestCode/TestCategory ;

save :f output.xml $out ;

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    Or maybe, more simply, remove any Test that doesn't match the criteria: 

    open 1.xml ;
delete ( //Test[not(starts-with(@name, "CheckType_"))]
       | //Test[starts-with(@name, "CheckType_")][not(context/value = 
+"XYZ")]
       ) ;

save :f 1.out ;

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    map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
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Re: xml to xml converter
by perlfan (Vicar) on Nov 10, 2021 at 10:56 UTC
    Idk if one of the utlilties provided by WC3's HTML/XML utilities, which reminds me Perl has no interface to this. When this comes up, I always want to create a module that embeds these tools (like DBD::SQLite embeds sqlite3) and provide a Perl interface to them...maybe one day. :)
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