Ashley Pond V — 바보 양키스

NAME

RSSycklr - (beta) Highly configurable recycling of syndication (RSS/Atom) feeds into tailored, guaranteed XHTML fragments.

SYNOPSIS

 use strict;
 use warnings;
 use RSSycklr;
 use Encode;
 
 my @feeds = ({ uri => "http://www.xkcd.com/atom.xml",
                max_display => 1 },
              { uri => "http://green.yahoo.com/rss/blogs/all" },
              { uri => "http://www.mnn.com/rss/all-mnn-content" },
              { uri => "http://feeds.grist.org/rss/gristfeed" },
              { uri => "http://green.yahoo.com/rss/featured" },
              { uri => "http://feeds.nationalgeographic.com/ng/NGM/NGM_Magazine" },
              { uri => "http://feeds.feedburner.com/greenlivingarticles" },
              { uri => "http://www.ecosherpa.com/feed/" },
              { uri => "http://www.groovygreen.com/groove/?feed=atom" },
              { uri => "http://blog.epa.gov/blog/feed/"},
              { uri => "http://www.unep.org/newscentre/rss/rss.asp?rss-id=pr&l=en" },
              { uri => "http://feeds.feedburner.com/treehuggersite" },
              { uri => "http://redgreenandblue.org/feed/" },
              { uri => "http://green.yahoo.com/rss/news" },
              { uri => "http://news.cnet.com/8300-11128_3-54.xml" },
              { uri => "http://news.google.com/news?rls=en-us&oe=UTF-8&um=1&tab=wn&hl=en&q=Environmental&ie=UTF-8&output=atom" },
              { title_override => "O NOES, IZ TEH DED",
                uri => "http://rss.news.yahoo.com/rss/obits", });
 
 my $rsklr = RSSycklr->new();
 
 binmode STDOUT, ":encoding(UTF-8)";
 $rsklr->config({ feeds => \@feeds,
                  title_only => 1 });

 # print $rsklr->as_string;
 
 while ( my $feed = $rsklr->next() )
 {
     print $feed->title_override || $feed->title;
     print "\n";
     for my $entry ( $feed->entries )
     {
         print " * ", $entry->title, "\n";
     }
 }

DESCRIPTION

This is a more of a mini-app engine than a pure module. RSSycklr is a package that wraps up the best parts of XML::Feed and HTML::Truncate then filters it through XML::LibXML to guarantee valid XHTML and adds a side of Template for auto-formatted output of XHTML fragments should you so desire.

This is probably easier to show with examples than explain. This is the part where I show, or maybe explain, someday. For now, take a look at the "CONFIGURATION" sample below and the source for the tool 'rssycklr' that comes with this distribution.

XHTML validation is currently based on "-//W3C//DTD XHTML 1.0 Transitional//EN" and errors are not fatal. You will be able to pick your DTD eventually and decide if errors are fatals or skip the entry or just complain.

METHODS

new

Create an RSSycklr object.

load_config

Takes a YAML file name or string. It must conform to the configuration format. No validation of input is done at this point. More config options will be probably be added soon. As it calls "config" underneath, loading configuration options will be add them to what's already there, not reset them.

config

Set/get hash reference of the configuration and raw feed data. Setting config is additive, each new hash reference is merged with the current config hash reference.

add_feeds

Takes an array ref of hash refs of feed info. uri is the only required key in the hash ref. Other possible keys are shown in "CONFIGURATION" below.

next

Iteration through feeds with delayed execution. Feeds are only fetched and cleaned-up as they are called. "next" is destructive and can be used in a while loop.

    while ( my $feed = $rssycklr->new() ) {
        print "Title: ", $feed->title, "\n";
    }
feeds

If you prefer to get your feeds at once in a list or an array ref, use "feeds". It iterates on "next" under the hood, therefore "next" will be empty after "feeds" has been called though "feeds" may be called repeatedly without refetching or parsing. If you "add_feeds" to add new feeds, next will able to iterate on those and "feeds" will add them to those already parsed and fetched.

Remember that each feed is a web request and they aren't done in any kind of parallel nature so you could expect a list of 20 feeds to return slowly, maybe very slowly.

as_string

Sort of does this-

 $rssycklr->process($rssycklr->template, { rssycklr => $rssycklr })
       or confess $rssycklr->tt2->error();

Can also be called for a return value, like so-

 my $output = $rssycklr->as_string;

In void context, it processes/prints to STDOUT.

 $rssycklr->as_string;
keep_tags

The list (stored as a hash ref) of tags which will be kept when creating ledes from entry bodies. The default list generally comprises the phrasal tags; e.g., <i/>, <q/>, <del/>, <dfn/>, <sup/>, et cetera.

 perl -MRSSycklr -MYAML -le '$rsklr = RSSycklr->new; print Dump $rsklr->keep_tags'

Example: dropping images-

 delete $rsklr->keep_tags->{img};

Example: drop all tags-

 $rsklr->keep_tags({});
tt2

The Template object we may create to do output. It's deferred so if you never ask for it, and never call its methods, it's never created.

template

The template that will be passed to "process" in Template. It can be a string (scalar ref), a file, or a file handle. The default is a string ref.

 perl -MRSSycklr -le '$rsklr = RSSycklr->new; print ${$rsklr->template}'
xml_parser

The XML::LibXML object.

html_to_dom

Passes an HTML fragment through some HTML::TokeParser::Simple sanity cleanup and returns an XML::LibXML::Document. This is an

truncater

The HTML::Truncate object.

BUILD

Internal method. To allow config and load_config to be passed as arguments. BUILD runs the methods at initialization if you do.

DELEGATED METHODS

As noted above, an RSSycklr object has a collection of objects it wrangles. You may call methods on it which get delegated t its objects. All the methods below belong to the indicated classes and may be treated exactly as the relevant documents show.

process

This is "process" in Template.

parse_html_string

"parse_html_string" in XML::LibXML. You also have access to "recover" in XML::LibXML::Parser and "recover_silently" in XML::LibXML::Parser which are set to "1" by default.

truncate

"truncate" in HTML::Truncate.

INTERNAL PACKAGES

RSSycklr::Feed

Calls from RSSyckler objects to "feeds" and "next" return RSSycklr::Feed objects. They are based on XML::Feed objects.

SELECT CONFIGURATION SETTINGS

More configuration settings are shown in the config example.

title_override

For some feeds, like say a search generated feed from Google, you might get back a title in the XML which is ridiculous for display; e.g., "bingo cards" +tacos site:example.org. In cases likes this it would be nice to provide your own title.

METHODS

entries

The processed entries from the feed which passed configuration filters.

count

The number of entries a feed has. Note, this is not the number of entries in the actual XML::Feed, but the number of entries which passed your configuration filters.

DELEGATED METHODS

The following delegate to the underlying XML::Feed object.

title
tagline
author
generator
language

RSSycklr::Feed::Entry

lede

The excerpted portion of the feed entry's content.

feed

The parent "RSSyckler::Feed" object.

DELEGATED METHODS

The following delegate to the underlying XML::Feed::Entry object.

title

This will eventually be replaced by a native method.

link
content
category
id
author
issued
modified

CONFIGURATION

Configuration is a hash in two levels. The top level contains defaults. The key feeds contains per feed settings. You can have max_display => 3 in the top, for example, but have max_display => 1 and max_display => 10 in individual feed data. Leaving max_display out of feed data would mean a feed would fall back to the top default setting 3.

 ---
 # length of entry excerpt to keep as "lede"
 excerpt_length: 110
 # don't do excerpts, titles, only
 title_only: ~
 # master setting for oldest entry age
 hours_back: 30
 # stop fetching at this point
 max_feeds: 10
 # master setting for entries to keep per feed
 max_display: 3
 # seconds to try a feed fetch before skipping
 timeout: 10
 # ellipsis on truncated ledes/titles
 ellipsis: " "
 # text for "read more" link
 read_more: [more]
 # css class for top <div> wrapper
 css_class: rssycklr
 # not implemented
 title_length: ~
 # not implemented, dl/dt/dd happens now
 excerpt_style: dl|p|br|ul
 # not implemented, ul/li happens now
 title_style: ul|p|br
 # this is hardcoded for now
 max_images: 1
 feed_title_tag: h4
 dtd: xhtml1-transitional.dtd
 feeds:
   - uri: http://green.yahoo.com/rss/blogs/all
     max_display: 5
     hours_back: 24
   - uri: http://sedition.com/feed/atom
     title_only: 1
     hours_back: 105
     timeout: 3
   - uri: http://dd.pangyre.org/dd.atom
     excerpt_length: 300
     hours_back: 48

Caveat: the ellipsis default is utf8 so set it to "..." (three periods) or &hellip; if it's going to cause a problem in your handling.

excerpt_length

How long to make ledes. This is passed through HTML::Truncate so it tries to count displayed characters, not real real characters; i.e., <p>Oh, Hai!</p> is counted as 8 characters, not 15. Default is at 170.

title_only

If true, don't do excerpts, only pull titles.

hours_back

Maximum age of feed entries to include.

max_display

How many entries from a feed to parse and keep.

timeout

How many seconds to wait for a feed fetch to return before skipping it.

ellipsis
read_more

Text for "read more" link.

css_class

The CSS class for the top <div/> wrapper.

max_images

Maximum images to keep in a lede. Hardcoded to 1 right now.

dtd
max_feeds

Stop fetching at this point.

dtd

The DTD to validate feed snippets against. The default is xhtml1-transitional.dtd. Also available: xhtml1-frameset.dtd, xhtml1-strict.dtd, and xhtml11.dtd. Because we use XML::LibXML to parse our snippets we cannot, and frankly wouldn't want to, support HTML 4 and earlier.

title_length

Not implemented.

excerpt_style

Not implemented, dl/dt/dd happens in template now.

title_style

Not implemented, ul/li happens now.

feed_title_tag

Settable; h4 in template now.

SAMPLE CSS

The image handling is probably the most important part. Feeds might return huge images or several images.

 .rssycklr {
   font-family: helvetica, sans-serif;
 }
 .rssycklr h4 {
   border-bottom: 1px solid #ccc;
   line-height: 100%;
 }
 .rssycklr h4 a {
   color:#039!important;
   text-decoration:none;
 }
 .rssycklr .datetime {
   color: #445;
   font-size: 80%;
 }
 .rssycklr a.readmore {
   text-decoration:none;
   font-size: 90%;
 }
 .rssycklr img {
   float: right;
   clear: right;
   width: 60px;
   margin: -3px 0 0 3px;
 }

AUTHOR

Ashley Pond V, <ashley@cpan.org>.

TODO

Collect errors for inspection in the object.

as_is flag?

Pass through the Pod to make it a bit more useful and less redundant on config stuff.

If abutting tags stripped tags are flow level, insert a newline...? Define the behavior in the config so even a ¶ or something could be inserted. Turn <br/>s into newlines? Use canTighten and isPhraseMarkup from HTML::Tagset to make these choices. Maybe this is where the DTDs should live too...?

Test timed out feeds.

next should be putting feeds aside for feeds?

Translate tags? To drop blockquote to q and h* to bold, etc?

Text only option for ledes? Makes it easier to work on that setting keep_tags to empty.

Put a name field for feeds to override the feed supplied title.

Make the validation controllable.

Make a master timeout vs a feed level timeout? No...

Make utf8 a settable...?

Move all the DTD handling, and all the other historical ones, HTML 1 and up, into a real distribution...? Ikegami's catalog stuff?

Make attribute filter configurable.

More tests.

Throw errors for extraneous or malformed config data.

Implement anything in the configuration example which reads, "not implemented." E.g., make the style/tags configurable for titles/ledes; e.g., dl|p|br|ul.

Submit a patch, or ticket, to Benjamin for a content_type XML::Feed::Entry. We're just assuming it's HTML.

Template->process should probably have a before call to allow the config to be merged into the top of the template data.

Make image count configurable.

Regex filters?

Chance of inclusion: a decimal so that a list of feeds 100 feeds with a level of 0.1 would only load (or rather try to) approximately 10 feeds.

BUGS AND LIMITATIONS

I love good feedback and bug reports. Please report any bugs or feature requests directly to me via email or through the web interface at http://rt.cpan.org/Public/Dist/Display.html?Name=RSSycklr.

THANKS TO

Stevan Little, Shawn M Moore, and Benjamin Trott. I had no idea how cool Moose and Mouse were before I put this together. They make very complicated interactions seem quite natural. I changed design and features three or four times putting this together and if the code had all been by hand it probably would have made me dump the project since I already had a perfectly serviceable program doing what it does. Instead, with Mouse, fairly deep changes were nearly trivial.

SEE ALSO

XML::Feed, XML::Feed::Entry, Mouse/Moose, XML::LibXML, Template, YAML, HTML::Truncate, DateTime, Scalar::Util, URI, Encode.

COPYRIGHT & LICENSE

Copyright (©) 2008-2010 Ashley Pond V.

This program is free software; you can redistribute it or modify it or both under the same terms as Perl itself.

DISCLAIMER OF WARRANTY

Because this software is licensed free of charge, there is no warranty for the software, to the extent permitted by applicable law. Except when otherwise stated in writing the copyright holders or other parties provide the software "as is" without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the software is with you. Should the software prove defective, you assume the cost of all necessary servicing, repair, or correction.

In no event unless required by applicable law or agreed to in writing will any copyright holder, or any other party who may modify and/or redistribute the software as permitted by the above licence, be liable to you for damages, including any general, special, incidental, or consequential damages arising out of the use or inability to use the software (including but not limited to loss of data or data being rendered inaccurate or losses sustained by you or third parties or a failure of the software to operate with any other software), even if such holder or other party has been advised of the possibility of such damages.