sorting on subkey of hash of hashes

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

I have this xml assigned to a variable called "$data":

<employees>
 <employee>
    <empid>9</empid>
    <fname>Joe</fname>
    <lname>A</lname>
  </employee>
  <employee>
    <empid>3</empid>
    <fname>Larry</fname>
    <lname>W</lname>
  </employee>
  <employee>
    <empid>7</empid>
    <fname>Perl</fname>
    <lname>L</lname>
  </employee>
</employees>
[download]

I have this perl script which uses XML::Simple to parse the xml file:

$parsed = eval {XMLin($data)};

if ($@) {
  print $@;
} else {
    <NEED SORTING CODE HERE>
}
[download]

So, what i need is to be able to sort the XML using the <empid> tag...so the xml should be sorted like this:

<employees>
  <employee>
    <empid>3</empid>
    <fname>Larry</fname>
    <lname>W</lname>
  </employee>
  <employee>
    <empid>7</empid>
    <fname>Perl</fname>
    <lname>6</lname>
  </employee>
  <employee>
    <empid>9</empid>
    <fname>Joe</fname>
    <lname>A</lname>
  </employee> 
</employees>
[download]

Comment on sorting on subkey of hash of hashes Select or Download Code

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Re: sorting on subkey of hash of hashes by Tanktalus (Canon) on Sep 16, 2005 at 03:47 UTC
Just the other day, I posted some code that sorted stuff in HTML using XML::Twig - I think that the same idea could be employed here.	[reply]
Re: sorting on subkey of hash of hashes by goldclaw (Scribe) on Sep 16, 2005 at 10:15 UTC
I dont know exactly the return of XLMin, but Im guessing you want soemthing like this: `my @sorted = sort { $a->{empid} <=> $b->{empid} } @{$parsed->{employees}};` [download] gc	[reply] [d/l]
Re: sorting on subkey of hash of hashes by radiantmatrix (Parson) on Sep 16, 2005 at 16:33 UTC
Your variable `$parsed` should now contain a hash ref which looks like: `{ 'employee' => [ { 'empid' => '9', 'lname' => 'A', 'fname' => 'Joe' }, { 'empid' => '3', 'lname' => 'W', 'fname' => 'Larry' }, { 'empid' => '7', 'lname' => '6', 'fname' => 'Perl' } ] };` [download] So, you want to sort the array referenced by the value of the 'employee' key: `@{ $parsed->{'employee'} } = sort { $a->{'empid'} <=> $b->{'empid'} } @{ $parsed->{'employee'} }; print XMLout($parsed, NoAttr=>1, RootName=>'employees');` [download] This will print: `<employees> <employee> <empid>3</empid> <fname>Larry</fname> <lname>W</lname> </employee> <employee> <empid>7</empid> <fname>Perl</fname> <lname>6</lname> </employee> <employee> <empid>9</empid> <fname>Joe</fname> <lname>A</lname> </employee> </employees>` [download] <-radiant.matrix-> Larry Wall is Yoda: there is no `try{}` (ok, except in Perl6; way to ruin a joke, Larry! ;P) The Code that can be seen is not the true Code "In any sufficiently large group of people, most are idiots" - Kaa's Law	[reply] [d/l] [select]