delete XML node in Perl

crmpicco · November 13th, 2006, 11:52 AM

These are my files, xmlremove.pl and employees.xml, is there any way to take the value of $xmlnode (i.e. the node number of employee)
and delete that node from the document using Perl?

xmlremove.pl

Code:

#! /usr/bin/perl

use CGI;
use XML::Simple;

$cgi = new CGI;
$xml = new XML::Simple;

$xmlnode = $cgi->param('delno');
$xmldata = $xml->XMLin('employees.xml');

print "Content-type: text/html\n\n";
print "XML Node: $xmlnode<br>";

employees.xml

Code:

<?xml version='1.0'?>
<staff>
    <employee>
        <name>
            <forename>John</forename>
            <surname>Doe</surname>
        </name>
        <age>
            <dob>10-02-1967</dob>
        </age>            
        <************>M</************>
        <department>
            <departmentname>Operations</departmentname>
            <title>Manager</title>
        </department>
        <location>
            <town>
                <name>Auchinleck</name>
                <county>East Ayrshire</county>
            </town>
        </location>
    </employee>
    <employee>
        <name>
            <forename>Craig R.</forename>
            <surname>Morton</surname>
        </name>   
        <age>
            <dob>05-03-1984</dob>
        </age>
        <************>M</************>
        <department>
            <departmentname>Internet</departmentname>
            <title>Developer</title>
        </department>
        <location>
            <town>
                <name>Ayr</name>
                <county>South Ayrshire</county>
            </town>
        </location>
    </employee>
    <employee>
        <name>
            <forename>William</forename>
            <surname>McCann</surname>
        </name>
        <age>
            <dob>15-07-1982</dob>
        </age>            
        <************>M</************>
        <department>
            <departmentname>Sales</departmentname>
            <title>Executive</title>
        </department>
        <location>
            <town>
                <name>Kilmarnock</name>
                <county>North Ayrshire</county>
            </town>
        </location>
    </employee>
</staff>

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crmpicco · November 14th, 2006, 06:06 AM

seemingly, something along the lines of

Code:

$xmlnode = $cgi->param('delno');
$xmldata = $xml->XMLin('employees.xml');

splice(@{$xmldata->{employee}},$xmlnode,-1);

should work, however it doesnt seem to have deleted anything

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crmpicco · November 15th, 2006, 08:08 AM

Thanks.
When i run this code, it produces this output. Is there any way of maintaining the original XML structure and node names?
xmlremove.pl

Code:

#! /usr/bin/perl

use CGI;
use XML::Simple;
use XML::Dumper;
use Data::Dumper;

$cgi = new CGI;
$xml = new XML::Simple;

my $dump = new XML::Dumper;

my $perl = '';
my $xmldoc = '';

$xmlnode = $cgi->param('delno');
$xmldata = $xml->XMLin('employees.xml');

$xmlval = $xmlnode-1;

splice(@{$xmldata->{employee}},$xmlval, 1);

$perl = $xmldata;

$file = "employees.xml";
$xmldoc = $dump->pl2xml($perl,$file);

$dump->pl2xml($perl,$file);

employees.xml

Code:

<perldata>
 <hashref memory_address="0xa7ab680">
  <item key="employee">
   <arrayref memory_address="0xa7dc1a8">
    <item key="0">
     <hashref memory_address="0xa7ab584">
      <item key="age">
       <hashref memory_address="0xa7ab338">
        <item key="dob">10-02-1967</item>
       </hashref>
      </item>
      <item key="department">
       <hashref memory_address="0xa7ab1d0">
        <item key="departmentname">Operations</item>
        <item key="title">Manager</item>
       </hashref>
      </item>
      <item key="location">
       <hashref memory_address="0xa7ab068">
        <item key="town">
         <hashref memory_address="0xa7aaffc">
          <item key="county">East Ayrshire</item>
          <item key="name">Auchinleck</item>
         </hashref>
        </item>
       </hashref>
      </item>
      <item key="name">
       <hashref memory_address="0xa7ab518">
        <item key="forename">John</item>
        <item key="surname">Doe</item>
       </hashref>
      </item>
      <item key="************">M</item>
     </hashref>
    </item>
    <item key="1">
     <hashref memory_address="0xa7aae64">
      <item key="age">
       <hashref memory_address="0xa7aac90">
        <item key="dob">05-03-1984</item>
       </hashref>
      </item>
      <item key="department">
       <hashref memory_address="0xa78c490">
        <item key="departmentname">Internet</item>
        <item key="title">Developer</item>
       </hashref>
      </item>
      <item key="location">
       <hashref memory_address="0xa798da4">
        <item key="town">
         <hashref memory_address="0xa798d38">
          <item key="county">South Ayrshire</item>
          <item key="name">Ayr</item>
         </hashref>
        </item>
       </hashref>
      </item>
      <item key="name">
       <hashref memory_address="0xa7aadf8">
        <item key="forename">Craig R.</item>
        <item key="surname">Morton</item>
       </hashref>
      </item>
      <item key="************">M</item>
     </hashref>
    </item>
   </arrayref>
  </item>
 </hashref>
</perldata>

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bluemin · November 28th, 2006, 09:54 AM

Hi,

Could you please try this code and see how it works. I thins it preserves the xml structure. I have tried to remove the second doc. from the original file.
------------------------------------------------------------------
undef $/;
$Str=(open (IN,"<$ARGV[0]"))?<IN>:die "$!";
$Str=~s/(<employee>)/<dummy>$1/g;
@count= split /<dummy>/,$Str;
undef $count[2];
$Str=join //,@count;
print $Str;
-------------------------------------------------------------------

Hope u find it useful

crmpicco · November 28th, 2006, 12:12 PM

hi there, thank you for that code. i had a play around with it. this is also a working script:

Code:

#! /usr/bin/perl

# Craig R Morton
# Remove a specified node and all its child nodes from an XML document
# Last_Edit: 21-Nov-2006

use CGI qw/:standard/;
use XML::Simple;

$cgi = new CGI;

my $xml = new XML::Simple;

my $xmldoc = '';

# retrieve the passed form field value from the previous page (delno) - (which node to delete)
$xmlnode = $cgi->param('delno');

# create a reference to the original XML file 'employees.xml'
$xmldata = $xml->XMLin('employees.xml');

# remove the passed node from the XML document
splice(@{$xmldata->{employee}},$xmlnode-1, 1);

$thexml = $xmldata;

my $xmldoc = XMLout($thexml, NoAttr => 1, KeyAttr => [], RootName => "staff",);

# open 'employees.xml' and write to it with the new XML structure
open(FILE, ">employees.xml") || die "Cannot open 'employees.xml'";
    print FILE "<?xml version='1.0'?>";        
        print FILE $xmldoc;
close(FILE) || warn "Error closing 'employees.xml'";

print "Content-type: text/html\n\n";
print <<ENDHTML;
<html>
<head>
<title>Delete Employee</title>
</head>
<body>
<br><br>
    <table align='center'>
        <tr>
            <td>You have deleted the employee from the XML document</td>
        </tr>
    </table>
</body>

ENDHTML

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