[EP-tech] Re: Exporting a .zip file

[Ian Stuart]

Answered my own question...

Set a local "initialise_fh" routine:

sub initialise_fh
{
	my( $plugin, $fh ) = @_;
	binmode("$fh:bytes");
}




On 20/11/12 09:49, Ian Stuart wrote:
> EPrints 3.2.2 on Solaris
>
> I'm writing an exporter to download the item as a .zip file (as in, a
> file that can be used in a SWORD deposit.)
>
> I can create the .zip file; I can send something called foo.zip back to
> the user.... but the thing I get back is not readable as a .zip file!
>
> Here is the code (with most of the integrity-checking & sanity-checking
> taken out)
>
> ---------------- code -----------------
>
> package EPrints::Plugin::Export::SWORD_Deposit_File;
>
> use strict;
> use warnings;
>
> use Archive::Zip qw( :ERROR_CODES :CONSTANTS);
>
> use EPrints::Plugin::Export::METS_Broker;
> our @ISA = qw( EPrints::Plugin::Export::METS_Broker );
>
> our $PREFIX = '';
>
> sub new
> {
>       my ($class, %opts) = @_;
>
>       my $self = $class->SUPER::new(%opts);
>
>       $self->{name}    = "foo";
>       $self->{accept}  = ['dataobj/eprint', 'list/eprint'];
>       $self->{visible} = "all";
>
>       $self->{xmlns}          = "foo";
>       $self->{schemaLocation} = "foo2";
>       $self->{suffix}         = ".zip";
>       $self->{mimetype}       = 'application/zip';
>
>       return $self;
> } ## end sub new
>
>
> sub output_dataobj
> {
>       my ($plugin, $dataobj) = @_;
>
>       my $text;
>       $text = <<EOX;
> <?xml version="1.0" encoding="utf-8" ?>
>
> EOX
>
>       my $xml = $plugin->xml_dataobj($dataobj);
>       $text .= EPrints::XML::to_string($xml);
>
>       # Use Archive::Zip to create the zip file
>       my $archive = Archive::Zip->new();
>
>       # Add the manifest as mets.xml
>
>       # for some reason, I can't get Archive::Zip to add a file with
>       # unicode characters, so this is a nasty hack, sorry
>       my $tmpdir = EPrints::TempDir->new(UNLINK => 0);
>       my $tmpfile = "${tmpdir}/mets.xml";
> warn "tempfile: $tmpfile\n";
>
>       # write out the xml file
>       my $FH;
>       open($FH, ">:utf8", "$tmpfile");
>       print $FH $text;
>       close($FH);
>       $archive->addFile($tmpfile, "mets.xml");
>
>       # end of fudge
>
>       # Each 'Document' is represented by a directory
>       # Each 'Document' many have a number of files
>       foreach my $doc ($dataobj->get_all_documents)
>       {
>
>           # In the zip file, we use file paths rather than URLs, however
>           # this routine is very similar to the methodology in
>           # EPrints::Plugin::Export::METS_Broker::_make_fileSec
>
>           # the docpath is the path to the document on the disk,
>           # formatted:
>           # /<EprintsRoot>/archive/<archiveID>/documents/<somepath>/<doc_id>
>           my $docroot = $doc->local_path;
>           $docroot =~ /\/(\d+)$/;
>           my $doc_id = $doc->get_id;
>
>           $archive->addTree($docroot, $doc_id);
>        } ## end foreach my $doc ($dataobj->get_all_documents...)
>
>
> my @M = $archive->memberNames();
> warn "Archive: @M\n";
>       # as of Perl 5.8.0, we can open a filehandle to variables
>       my $buffer = "";
>       open(my $fh, ">:bytes", \$buffer) || warn "Can't open a buffer in
> memory\n";
>
>       unless ($archive->writeToFileHandle($fh) == AZ_OK)
>       {
>           warn "failed to write archive into scalar\n";
>       }
>       close $fh;
> warn "Written archive into scalar\n";
> warn "size:". length($buffer)."\n";
> $archive->writeToFileNamed("${tmpdir}/deposit.zip");
>
>      return $buffer;
> } ## end sub output_dataobj
>
> 1;
> ---------------- code -----------------
>
> As you can see, I've got some debugging going on
>
> tempfile: /var/tmp/n2grhkaewB/mets.xml
> Archive: mets.xml 474/ 474/2012-09-06767_121010093659.zip
> Written archive into scalar
> size:2638
>
> and looking at the .zip file:
> [broker at devel:Export]: unzip -l /var/tmp/n2grhkaewB/deposit.zip
> Archive:  /var/tmp/n2grhkaewB/deposit.zip
>     Length     Date   Time    Name
>    --------    ----   ----    ----
>        4206  11-20-12 09:29   mets.xml
>           0  10-10-12 14:37   474/
>        1178  10-10-12 14:37   474/2012-09-06767_121010093659.zip
>    --------                   -------
>        5384                   3 files
>
> So.... I can obviously MAKE the file.... I just can't send it back to
> the user sensibly.
>
> Anyone done this?
> If not - anyone any suggestions as to why it's not working?
>
>
>
>
> Oh - and a SWORD transfer exporter is fine: it's essentially this code,
> but then uses LWP::UserAgent to do a post:
>
>     my $ua      = LWP::UserAgent->new();
>     my $rxml    = $plugin->{session}->xml;
>     my $returns = $rxml->create_element("returns");
>     my $req = HTTP::Request->new(POST => $target->{uri});
>
>     # Tell SWORD to process the contents of the zip file as my format
>     $req->header(
>              'X-Packaging'         => 'http://opendepot.org/broker/1.0',
>              'X-No-Op'             => 'false',
>              'X-Verbose'           => 'false',
>              'Content-Disposition' => 'filename=sword_deposit.zip',
>              'filename'            => 'sword_deposit.zip',
>                  );
>     $req->content_type('application/zip');
>     $req->content($buffer);
>     my $res = $ua->request($req);
>     if ($res->is_success)
>     {
>        my $content_dom = $rxml->parse_string($res->content);
>        my $fragment = $content_dom->getElementsByTagName('entry')->item(0);
>        $return->appendChild($fragment);
>     } ## end if ($res->is_success)
>
>


-- 

Ian Stuart.
Developer: ORI, RJ-Broker, and OpenDepot.org
Bibliographics and Multimedia Service Delivery team,
EDINA,
The University of Edinburgh.

http://edina.ac.uk/

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