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XML::RSS::Podcast update

1st August 2008

It seems that a few of you are using or trying to use the XML::RSS::Podcast module I published on this blog. As was mentioned there, modern version of XML::RSS do not support the encode function required for generating well-formed XML documents.

That's all changed thanks to Rohan Carly. [Add your thanks to Rohan in the comments.]

I present the complete version of XML::RSS::Podcast below. If you find this module useful, I'll attempt to create a CPAN module for it.

package XML::RSS::Podcast;
use XML::RSS;
use HTML::Entities qw[encode_entities_numeric encode_entities];
@XML::RSS::Podcast::ISA = qw[XML::RSS];
our $VERSION = q[1.1];

# encode by Rohan Carly
# Stolen from XML::RSS::Private::Output::Base;
sub encode {
  my ($self,$text) = @_;
  return unless defined($text);
  
  my $encoded_text = '';
  
  while ($text =~ s,(.*?)(<!\[CDATA\[.*?\]\]>),,s) {
    # we use &named; entities here because it's HTML
    $encoded_text .= encode_entities($1) . $2;
  }
  
  # we use numeric entities here because it's XML
  $encoded_text .= encode_entities_numeric($text);
  
  return $encoded_text;
};

sub as_string {
  my $self = shift;
  return $self->as_podcast_rss;
}

sub as_podcast_rss {
  my $self = shift;
  my $enc = $self->{encoding};
  my $output = qq[<?xml version="1.0" encoding="$enc"?>
<rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" 
     version="2.0">];
          
  $output .= $self->podcast_start_channel;
  
  for my $i (@{$self->{items}}) {
    $output .= $self->podcast_item($i);
  }

  $output .= $self->podcast_end_channel;
  return $output .= "\n</rss>\n";
}

sub podcast_start_channel {
  my $self = shift;
  my @fields = qw[ttl title description link language 
                  pubDate lastBuildDate creator 
                  webMaster copyright
                 ];
  my @image_fields  = qw[title url description link     
                         width height];
  my @itunes_fields = qw[subtitle author summary
                         image explicit]; # Thanks Rohan
  
  my $output = "<channel>\n";
  
  for my $f (@fields) {
    if (defined($self->{channel}->{$f})) {
      my $s = $self->encode($self->{channel}->{$f});
      $output .= "\t<$f>$s</$f>\n";
    }
  }
  
  my $seen_image = 0;
  for my $f (@image_fields) {
    if (defined($self->{image}->{$f})) {
      unless ($seen_image) {
        $output .= "\t<image>\n";
        $seen_image = 1;
      }
      my $s = $self->encode($self->{image}->{$f});
      $output .= "\t\t<$f>$s</$f>\n";
    }
  }
  
  if ($seen_image) {
    $output .= "\t</image>\n";
  }
  
  # Owner name/email not handled
  for my $f (@itunes_fields) {
    if (defined($self->{channel}->{itunes}->{$f})) {
      my $s=$self->encode($self->{channel}->{itunes}->{$f});
      $output .= "\t<itunes:$f>$s</itunes:$f>\n";
    }
  }
  # Rohan's sub-cat handling code
  # Expects an array: [category, sub-category]
  if (ref $self->{channel}->{itunes}->{category} eq 'ARRAY') {
    my $major = $self->encode(${$self->{channel}->{itunes}->{category}}[0]);
    my $minor = $self->encode(${$self->{channel}->{itunes}->{category}}[1]);
    $output .= qq[\t<itunes:category text="$major">\n];
    $output .= qq[\t\t<itunes:category text="$minor">\n];
    $output .= qq[\t\t</itunes:category>\n];
    $output .= qq[\t</itunes:category>\n];
  }

  return $output . "\n";
}
  
sub podcast_end_channel {
  return "</channel>\n";
}

sub podcast_item {
  my $self = shift;
  my $item = shift;
  
  my @fields = qw[title guid pubDate description link];
  my @itunes_fields = qw[author subtitle summary 
                         duration keywords explicit];
  
  my $output = "\t<item>\n";
  for my $f (@fields) {
                     
    if (defined($item->{$f})) {
      $s = $self->encode($item->{$f});
      my $perma = "";
      if ($f eq "guid") {
        $perma = qq[isPermaLink="false"];
      }
      $output .= "\t\t<$f$perma>$s</$f>\n";
    }
  }
  
  if (ref $item->{enclosure}) {
    $output .= "<enclosure";
    for my $f (qw[url length type]) {
      if (defined $item->{enclosure}->{$f}) {
        $output .= sprintf("$f=%s", $self->encode($item->{enclosure}->{$f}));
      }
    }
    $output .= "/>";
  }
  
  for my $f (@itunes_fields) {
    if (defined $item->{itunes}->{$f}) {
      $s = $self->encode($item->{itunes}->{$f});
      $output .= "\t\t<itunes:$f>$s</itunes:$f>\n";
    }
  }
  return $output .= "\t</item>\n";
}
1;

For an example of usage, please see the previous post cited above. Report bugs in the comments or through email. Thanks.

Tags: computers, perl, podcast, xml