Headlines Plugin

<--
   Contributions to this plugin are appreciated. Please update the plugin page at
   http://twiki.org/cgi-bin/view/Plugins/HeadlinesPlugin or provide feedback at
   http://twiki.org/cgi-bin/view/Plugins/HeadlinesPluginDev.
   If you are a TWiki contributor please update the plugin in the SVN repository.
-->

Description

This plugin displays RSS and ATOM feeds from news sites. Use it to build news portals that show headline news.

Notes:

• RSS (Rich Site Summary) is an XML standard used to publish frequently updated works such as blog entries, news headlines and audio.
• Atom is an XML syndication format used for web feeds.
• Syndic8.com at http://www.syndic8.com/ lists many RSS and ATOM feeds.

Syntax Rules

%HEADLINES{"..."}%

The header and format parameters might also use variables rendering the dc, image and content namespace information. Note, that only bits of interest have been implemented so far and those namespaces might not be implemented fully yet.

Rendering the dc namespace

The following variables are extracting the dc namespace info, that could be used in header and format. Note that some of the variables are already used above. This is done by purpose to use different feeds with the same formatting parameters. If there's a conflict the non-dc tags have higher precedence, i.e. a <title> content </title> is preferred over <dc:title> content </dc:title>.

• $title: channel/article title (dc:title)
• $creator: channel creator (dc:creator)
• $subject: subject text; this will also add an image according to the subject hash list, see above (dc:subject)
• $description: ... (dc:description)
• $publisher: the channel/article publisher (dc:publisher)
• $contributor: ... (dc:contributor)
• $date: ... (dc:date)
• $type: ... (dc:type)
• $format: ... (dc:format)
• $identifier: ... (dc:identifier)
• $source: ... (dc:source)
• $language: ... (dc:language)
• $relation: ... (dc:relation)
• $coverage: ... (dc: coverage)
• $rights: ... (dc: rights)

Rendering the image namespace

An image:item is converted into an <img> tag using the following mappings:

• src: image url (rdf:about attribute of the image.item tag)
• alt: image title (title)
• width: image width (image:width)
• height: image height image:height)

Rendering the content namespace

The variable $content is referring to the <content:encoding> content </content:encoding>.

Examples

Slashdot News

Write

%HEADLINES{ "http://slashdot.org/slashdot.rdf" 
  header="*[[$link][$title]]:* $description" 
  format="$t* [[$link][$title]]"
  limit="4"
}%

HeadlinesPlugin ERROR: 501 Protocol scheme 'https' is not supported (LWP::Protocol::https not installed)

Wired Enterprise Feed

Write

%HEADLINES{ "http://feeds.wired.com/wiredenterprise/" limit="3" }%

to get the latest postings on the Wired.com feed on enterprise:

HeadlinesPlugin ERROR: 501 Protocol scheme 'https' is not supported (LWP::Protocol::https not installed)

Plugin Settings

Plugin settings are stored as preferences settings. Do not change the settings here, they are here only for illustration purposes showing the default values. Define the settings in Main.TWikiPreferences. For example, to customize the HEADLINESPLUGIN_USERAGENTNAME setting, add a * Set HEADLINESPLUGIN_USERAGENTNAME = ... bullet in Main.TWikiPreferences.

• Refresh rate in minutes for cached feeds. Set to 0 to disable caching:
  • Set HEADLINESPLUGIN_REFRESH = 60

• Maximum number of items shown:
  • Set HEADLINESPLUGIN_LIMIT = 100

• Use LWP::UserAgent if set to 1, or fallback to TWiki's internal getUrl() method if set to 0:
  • Set HEADLINESPLUGIN_USELWPUSERAGENT = 1

• Timeout fetching a feed using the LWP::UserAgent:
  • Set HEADLINESPLUGIN_USERAGENTTIMEOUT = 20

• Name of user agent:
  • Set HEADLINESPLUGIN_USERAGENTNAME = TWikiHeadlinesPlugin/2011-07-08

• Default header: (variables are explained in the syntax rules)

      * Set HEADLINESPLUGIN_HEADER = <div class="headlinesChannel"><div class="headlinesLogo"><img src="$imageurl" alt="$imagetitle" border="0" />%BR%</div><div class="headlinesTitle">$n---+!! <a href="$link">$title</a></div><div class="headlinesDate">$date</div><div class="headlinesDescription">$description</div><div class="headlinesRight">$rights</div></div>

• Default format of one item: (variables are explained in the syntax rules)

      * Set HEADLINESPLUGIN_FORMAT = <div class="headlinesArticle"><div class="headlinesTitle"><a href="$link">$title</a></div>$n<span class="headlinesDate">$date</span> <span class="headlinesCreator"> $creator</span> <span class="headlinesSubject"> $subject </span>$n<div class="headlinesText"> $description</div></div>

• Values taken from configure: (only supported if CPAN:LWP is installed)
  • $TWiki::cfg{PROXY}{HOST} - proxy host, such as "proxy.example.com";
  • $TWiki::cfg{PROXY}{PORT} - proxy port, such as "8080";
  • $TWiki::cfg{PROXY}{SkipProxyForDomains} - domains excluded from proxy, such as "intra.example.com, bugs.example.com";

Style Sheets

The default HEADER and FORMAT settings use the following styles. See the style.css file defining the default CSS properties (indentation illustrates enclosure).

• headlinesRss: output of the HeadlinesPlugin (div)
  • headlinesChannel: channel header (div)
    • headlinesLogo: channel logo (div)
    • headlinesTitle: channel title (div)
    • headlinesDate: channel date (div)
    • headlinesDescription: channel description (div)
    • headlinesRight: channel copyright (div)
  • headlinesArticle: one news item (div)
    • headlinesTitle: article title (div)
    • headlinesDate: article date (span)
    • headlinesCreator: author of article (span)
    • headlinesSubject: subect category of the article (span)
    • headlinesText: article text (div)

Plugin Installation Instructions

This is a pre-installed plugin. TWiki administrators can upgrade the plugin as needed on the TWiki server.

Show details Hide details

<--/twistyPlugin twikiMakeVisibleInline-->

<--/twistyPlugin-->

Plugin Info

• One line description, shown in the TextFormattingRules topic:
  • Set SHORTDESCRIPTION = Show headline news in TWiki pages based on RSS and ATOM news feeds from external sites

Plugin Author:

TWiki:Main.PeterThoeny, TWiki:Main.MichaelDaum

Show Change History Hide Change History

<--/twistyPlugin twikiMakeVisibleInline-->

2013-11-18:	TWikibug:Item7385: Encode "[" and "]" to avoid problems with TWiki [[...][...]] links; code-refactor to use registerTagHandler and OO style.
2013-02-16:	TWikibug:Item7091: Use TWISTY in installation instructions section and change history
2013-01-29:	TWikibug:Item7131: HeadlinesPlugin doesn't match pattern in multiple lines.
2012-12-10:	TWikibug:Item7070: HeadlinesPlugin doesn't support multiple disks.
2012-11-13:	TWikibug:Item7016: Restore changes for earlier versions with LWP
2012-11-13:	TWikibug:Item7020: Categorize TWiki Variable
2012-10-31:	TWikibug:Item7016: Utilize <guid> value when it is available
2012-09-05:	TWikibug:Item6837: Doc fixes
2011-07-17:	TWikibug:Item6764: Add VarHEADLINES variable documentation; doc improvements; setting NO_PREFS_IN_TOPIC
2011-07-08:	TWikibug:Item6725: Change global package variables from "use vars" to "our"
2010-05-16:	TWikibug:Item6433: More doc improvements
2010-04-25:	TWikibug:Item6433: Doc fix: Changing TWIKIWEB to SYSTEMWEB
2010-02-27:	TWikibug:Item6313: Fixed bug in ATOM feed with <link ...></link> instead of <link ... /> -- Peter Thoeny
2009-09-30:	fixed bug in lastBuildDate of feeds affecting touch parameter functionality -- Peter Thoeny
2009-08-29:	added touch parameter -- Peter Thoeny
12 Feb 2009:	{PROXY}{HOST} supports domain with and without protocol -- Peter Thoeny
06 Feb 2009:	added {PROXY}{SkipProxyForDomains} configure setting, added USERAGENTNAME plugin setting -- Peter Thoeny
11 Dec 2008:	added {PROXY}{HOST} and {PROXY}{PORT} configure settings -- Peter Thoeny
13 Sep 2007:	fixed parsing of content:encoded
23 Jul 2006:	improved atom parser; if a posting has no title default to 'Untitled'
26 Apr 2006:	added lazy compilation
10 Feb 2006:	packaged using the TWiki:Plugins/BuildContrib; minor fixes
03 Feb 2006:	off-by-one: limit="n" returned n+1 articles; make FORMAT and HEADER format strings more robust
23 Jan 2006:	released v2.00
05 Dec 2005:	internal feed urls must be absolute
02 Dec 2005:	added web.topic shorthand for internal feeds
29 Nov 2005:	fixed CDATA handling
21 Nov 2005:	added ATOM support; extended RSS support; added dublin core support; added content support; optionally using LWP to fetch feeds to follow redirections; corrected CPAN dependencies ; recoding special chars from html integer to entity encoding to increase browser compatibility; added css support; use getWorkArea() if available
11 May 2005:	TWiki:Main.WillNorris: added DevelopBranch compatability
31 Oct 2004:	Fixed taint issue by TWiki:Main.AdrianWeiler; small performance improvement
29 Oct 2004:	Fixed issue of external caching if mod_perl or SpeedyCGI is used
02 Aug 2002:	Implemented caching of feeds, thanks to TWiki:Main/RobDuarte
11 Jun 2002:	Initial version (V1.000)

<--/twistyPlugin-->

Perl Version:	5.8
Plugin Benchmark:	GoodStyle 100%, FormattedSearch 99.5%, HeadlinesPlugin 94%
Plugin Home:	http://TWiki.org/cgi-bin/view/Plugins/HeadlinesPlugin
Feedback:	http://TWiki.org/cgi-bin/view/Plugins/HeadlinesPluginDev
Appraisal:	http://TWiki.org/cgi-bin/view/Plugins/HeadlinesPluginAppraisal

Related Topics: VarHEADLINES, TWikiPlugins, AdminDocumentationCategory, TWikiPreferences