Editing Contribute: Plugins/ExportPluginsZip (section)

==== Dealing With Files ====
The files method of the Document object returns a hash whose keys are file names and values are file sizes.
<pre>
      my %files = $doc->files;
</pre>

We loop over each file belonging to the document, in most cases there will only be one file.
<pre>
      foreach my $filename (sort keys %files)
      {
        my $filepath = $subdirpath.$filename;
        my $file = $doc->local_path.'/'.$filename;
</pre>

We need to read the contents of the file and add it to a file in the zip. First we'll create another in-memory file to hold the contents.
<pre>
        my $data = '';
        open (my $datafh ,'>', \$data);
</pre>

We open our file and print it straight out to our in-memory file.
<pre>
        open (INFH, "<$file") or die ("Could not open file $file");
        while (<INFH>)
        {
          print {$datafh} $_;
        }
        close INFH;
</pre>

Then we add the file data to our file.
<pre>
        $zip->add_file($filepath, $data);
</pre>

Finally we add the [http://en.wikipedia.org/wiki/Document_Object_Model DOM] object for our eprint to the index.
<pre>
    $index .= EPrints::XML::to_string($div);
</pre>