NAME
XML::FeedPP -- Parse/write/merge/edit RSS/RDF/Atom syndication feeds
SYNOPSIS
Get an RSS file and parse it:
my $source = 'http://use.perl.org/index.rss';
my $feed = XML::FeedPP->new( $source );
print "Title: ", $feed->title(), "\n";
print "Date: ", $feed->pubDate(), "\n";
foreach my $item ( $feed->get_item() ) {
print "URL: ", $item->link(), "\n";
print "Title: ", $item->title(), "\n";
}
Generate an RDF file and save it:
my $feed = XML::FeedPP::RDF->new();
$feed->title( "use Perl" );
$feed->link( "http://use.perl.org/" );
$feed->pubDate( "Thu, 23 Feb 2006 14:43:43 +0900" );
my $item = $feed->add_item( "http://search.cpan.org/~kawasaki/XML-TreePP-0.02" );
$item->title( "Pure Perl implementation for parsing/writing xml file" );
$item->pubDate( "2006-02-23T14:43:43+09:00" );
$feed->to_file( "index.rdf" );
Convert some RSS/RDF files to Atom format:
my $feed = XML::FeedPP::Atom::Atom10->new(); # create empty atom file
$feed->merge( "rss.xml" ); # load local RSS file
$feed->merge( "http://www.kawa.net/index.rdf" ); # load remote RDF file
my $now = time();
$feed->pubDate( $now ); # touch date
my $atom = $feed->to_string(); # get Atom source code
DESCRIPTION
"XML::FeedPP" is an all-purpose syndication utility that parses and
publishes RSS 2.0, RSS 1.0 (RDF), Atom 0.3 and 1.0 feeds. It allows you
to add new content, merge feeds, and convert among these various
formats. It is a pure Perl implementation and does not require any other
module except for XML::TreePP.
METHODS FOR FEED
$feed = XML::FeedPP->new( "index.rss" );
This constructor method creates an "XML::FeedPP" feed instance. The only
argument is the local filename. The format of $source must be one of the
supported feed formats -- RSS, RDF or Atom -- or execution is halted.
$feed = XML::FeedPP->new( "http://use.perl.org/index.rss" );
The URL on the remote web server is also available as the first
argument. LWP::UserAgent is required to download it.
$feed = XML::FeedPP->new( '<rss version="2.0">...' );
The XML source code is also available as the first argument.
$feed = XML::FeedPP->new( $source, -type => $type );
The "-type" argument allows you to specify type of $source from choice
of 'file', 'url' or 'string'.
$feed = XML::FeedPP->new( $source, utf8_flag => 1 );
This makes utf8 flag on for every feed elements. Perl 5.8.1 or later is
required to use this.
Note that any other options for "XML::TreePP" constructor are also
allowed like this. See more detail on XML::TreePP.
$feed = XML::FeedPP::RSS->new( $source );
This constructor method creates an instance for an RSS 2.0 feed. The
first argument is optional, but must be valid an RSS source if
specified. This method returns an empty instance when $source is
undefined.
$feed = XML::FeedPP::RDF->new( $source );
This constructor method creates an instance for RSS 1.0 (RDF) feed. The
first argument is optional, but must be an RDF source if specified. This
method returns an empty instance when $source is undefined.
$feed = XML::FeedPP::Atom->new( $source );
This constructor method creates an instance for an Atom 0.3/1.0 feed.
The first argument is optional, but must be an Atom source if specified.
This method returns an empty instance when $source is undefined.
Atom 1.0 feed is also supported since "XML::FeedPP" version 0.30. Atom
0.3 is still default, however, future version of this module would
create Atom 1.0 as default.
$feed = XML::FeedPP::Atom::Atom03->new();
This creates an empty Atom 0.3 instance obviously.
$feed = XML::FeedPP::Atom::Atom10->new();
This creates an empty Atom 1.0 instance intended.
$feed = XML::FeedPP::RSS->new( link => $link, title => $tile, ... );
This creates a RSS instance which has "link", "title" elements etc.
$feed->load( $source );
This method loads an RSS/RDF/Atom file, much like "new()" method does.
$feed->merge( $source );
This method merges an RSS/RDF/Atom file into the existing $feed
instance. Top-level metadata from the imported feed is incorporated only
if missing from the present feed.
$string = $feed->to_string( $encoding );
This method generates XML source as string and returns it. The output
$encoding is optional, and the default encoding is 'UTF-8'. On Perl 5.8
and later, any encodings supported by the Encode module are available.
On Perl 5.005 and 5.6.1, only four encodings supported by the Jcode
module are available: 'UTF-8', 'Shift_JIS', 'EUC-JP' and 'ISO-2022-JP'.
'UTF-8' is recommended for overall compatibility.
$string = $feed->to_string( indent => 4 );
This makes the output more human readable by indenting appropriately.
This does not strictly follow the XML specification but does looks nice.
Note that any other options for "XML::TreePP" constructor are also
allowed like this. See more detail on XML::TreePP.
$feed->to_file( $filename, $encoding );
This method generate an XML file. The output $encoding is optional, and
the default is 'UTF-8'.
$item = $feed->add_item( $link );
This method creates a new item/entry and returns its instance. A
mandatory $link argument is the URL of the new item/entry.
$item = $feed->add_item( $srcitem );
This method duplicates an item/entry and adds it to $feed. $srcitem is a
"XML::FeedPP::*::Item" class's instance which is returned by
"get_item()" method, as described above.
$item = $feed->add_item( link => $link, title => $tile, ... );
This method creates an new item/entry which has "link", "title" elements
etc.
$item = $feed->get_item( $index );
This method returns item(s) in a $feed. A valid zero-based array $index
returns the corresponding item in the feed. An invalid $index yields
undef. If $index is undefined in array context, it returns an array of
all items. If $index is undefined in scalar context, it returns the
number of items.
@items = $feed->match_item( link => qr/.../, title => qr/.../, ... );
This method finds item(s) which match all regular expressions given.
This method returns an array of all matched items in array context. This
method returns the first matched item in scalar context.
$feed->remove_item( $index or $link );
This method removes an item/entry specified by zero-based array index or
link URL.
$feed->clear_item();
This method removes all items/entries from the $feed.
$feed->sort_item();
This method sorts the order of items in $feed by "pubDate".
$feed->uniq_item();
This method makes items unique. The second and succeeding items that
have the same link URL are removed.
$feed->normalize();
This method calls both the "sort_item()" and "uniq_item()" methods.
$feed->limit_item( $num );
Removes items in excess of the specified numeric limit. Items at the end
of the list are removed. When preceded by "sort_item()" or
"normalize()", this deletes more recent items.
$feed->xmlns( "xmlns:media" => "http://search.yahoo.com/mrss" );
Adds an XML namespace at the document root of the feed.
$url = $feed->xmlns( "xmlns:media" );
Returns the URL of the specified XML namespace.
@list = $feed->xmlns();
Returns the list of all XML namespaces used in $feed.
METHODS FOR CHANNEL
$feed->title( $text );
This method sets/gets the feed's "title" element, returning its current
value when $title is undefined.
$feed->description( $html );
This method sets/gets the feed's "description" element in plain text or
HTML, returning its current value when $html is undefined. It is mapped
to "content" element for Atom 0.3/1.0.
$feed->pubDate( $date );
This method sets/gets the feed's "pubDate" element for RSS, returning
its current value when $date is undefined. It is mapped to "dc:date"
element for RDF, "modified" for Atom 0.3, and "updated" for Atom 1.0.
See also "DATE AND TIME FORMATS" section below.
$feed->copyright( $text );
This method sets/gets the feed's "copyright" element for RSS, returning
its current value when $text is undefined. It is mapped to "dc:rights"
element for RDF, "copyright" for Atom 0.3, and "rights" for Atom 1.0.
$feed->link( $url );
This method sets/gets the URL of the web site as the feed's "link"
element, returning its current value when the $url is undefined.
$feed->language( $lang );
This method sets/gets the feed's "language" element for RSS, returning
its current value when the $lang is undefined. It is mapped to
"dc:language" element for RDF, "feed xml:lang=""" for Atom 0.3/1.0.
$feed->image( $url, $title, $link, $description, $width, $height )
This method sets/gets the feed's "image" element and its child nodes,
returning a list of current values when any arguments are undefined.
METHODS FOR ITEM
$item->title( $text );
This method sets/gets the item's "title" element, returning its current
value when the $text is undefined.
$item->description( $html );
This method sets/gets the item's "description" element in HTML or plain
text, returning its current value when $text is undefined. It is mapped
to "content" element for Atom 0.3/1.0.
$item->pubDate( $date );
This method sets/gets the item's "pubDate" element, returning its
current value when $date is undefined. It is mapped to "dc:date" element
for RDF, "modified" for Atom 0.3, and "updated" for Atom 1.0. See also
"DATE AND TIME FORMATS" section below.
$item->category( $text );
This method sets/gets the item's "category" element. returning its
current value when $text is undefined. It is mapped to "dc:subject"
element for RDF, and ignored for Atom 0.3.
$item->author( $name );
This method sets/gets the item's "author" element, returning its current
value when $name is undefined. It is mapped to "dc:creator" element for
RDF, "author" for Atom 0.3/1.0.
$item->guid( $guid, isPermaLink => $bool );
This method sets/gets the item's "guid" element, returning its current
value when $guid is undefined. It is mapped to "id" element for Atom,
and ignored for RDF. The second argument is optional.
$item->set( $key => $value, ... );
This method sets customized node values or attributes. See also
"ACCESSOR AND MUTATORS" section below.
$value = $item->get( $key );
This method returns the node value or attribute. See also "ACCESSOR AND
MUTATORS" section below.
$link = $item->link();
This method returns the item's "link" element.
ACCESSOR AND MUTATORS
This module understands only subset of "rdf:*", "dc:*" modules and
RSS/RDF/Atom's default namespaces by itself. There are NO native methods
for any other external modules, such as "media:*". But "set()" and
"get()" methods are available to get/set the value of any elements or
attributes for these modules.
$item->set( "module:name" => $value );
This sets the value of the child node:
<item><module:name>$value</module:name>...</item>
$item->set( "module:name@attr" => $value );
This sets the value of the child node's attribute:
<item><module:name attr="$value" />...</item>
$item->set( "@attr" => $value );
This sets the value of the item's attribute:
<item attr="$value">...</item>
$item->set( "hoge/pomu@hare" => $value );
This code sets the value of the child node's child node's attribute:
<item><hoge><pomu attr="$value" /></hoge>...</item>
DATE AND TIME FORMATS
"XML::FeedPP" allows you to describe date/time using any of the three
following formats:
$date = "Thu, 23 Feb 2006 14:43:43 +0900";
This is the HTTP protocol's preferred format and RSS 2.0's native
format, as defined by RFC 1123.
$date = "2006-02-23T14:43:43+09:00";
W3CDTF is the native format of RDF, as defined by ISO 8601.
$date = 1140705823;
The last format is the number of seconds since the epoch,
"1970-01-01T00:00:00Z". You know, this is the native format of Perl's
"time()" function.
USING MEDIA RSS
To publish Media RSS, add the "media" namespace then use "set()" setter
method to manipulate "media:content" element, etc.
my $feed = XML::FeedPP::RSS->new();
$feed->xmlns('xmlns:media' => 'http://search.yahoo.com/mrss/');
my $item = $feed->add_item('http://www.example.com/index.html');
$item->set('media:content@url' => 'http://www.example.com/image.jpg');
$item->set('media:content@type' => 'image/jpeg');
$item->set('media:content@width' => 640);
$item->set('media:content@height' => 480);
MODULE DEPENDENCIES
"XML::FeedPP" requires only XML::TreePP which likewise is a pure Perl
implementation. The standard LWP::UserAgent is required to download
feeds from remote web servers. "Jcode.pm" is required to convert
Japanese encodings on Perl 5.005 and 5.6.1, but is NOT required on Perl
5.8.x and later.
AUTHOR
Yusuke Kawasaki, http://www.kawa.net/
COPYRIGHT
The following copyright notice applies to all the files provided in this
distribution, including binary files, unless explicitly noted otherwise.
Copyright 2006-2011 Yusuke Kawasaki
LICENSE
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.