Find Elsewhere Plugin

Automatically link to another web(s) if a topic isn't found in the current web.

This plugin is useful - for example - for a Foswiki site that wants to implement a glossary/dictionary web where common terms are defined and stored together. Without this plugin:

• Each web would have to create their own topic for a common term
• Or would have to link to or INCLUDE the topic from where it is defined
• Or authors would have to remember to put the Web name in front of the topic name, such as System.WikiWord

Syntax Rules

No new syntax is introduced. However, new automatic WikiWord linking will occur.

If a topic or abbreviation is not found in the current web, this plugin will look through the webs listed in the LOOKELSEWHEREWEBS preference. If the topic is found (as it looks through the webs in their listed order), it will create one or more links, depending on the number of topics found.

Single hits

Test case	Input	Output (if installed)	Expected
Found here	WebHome	WebHome	WebHome
Found singular here	WebHomes	WebHomes	WebHomes
Found elsewhere	WebSearch	WebSearch	WebSearch
Found elsewhere (LOOKELSEWHEREFORLOCAL enabled)	System.WikiUsers	WikiUsers	WikiUsers
Found elsewhere (LOOKELSEWHEREFORLOCAL disabled)	System.WikiUsers	WikiUsers	WikiUsers (non-existing)
Found elsewhere	[[AdminGroup][wiki admins]]	wiki admins	wiki admins
Don't touch direct links	[[Main.AdminGroup][wiki admins]]	wiki admins	wiki admins
Found singular elsewhere	WebSearches	WebSearches	WebSearches
Found elsewhere, spaced wiki word	[[Web search]]	Web search	Web search
Found elsewhere, abbrev	ACRONYM	ACRONYM	(If ACRONYM is a topic defined in one of the LOOKELSEWHERE webs, a link to it should show up)
Found elsewhere, abbrev w. alt. linktext	[[ACRONYM][acronym link text]]	acronym link text	(If ACRONYM is a topic defined in one of the LOOKELSEWHERE webs, a link to it should show up)
Escaped with <noautolink>	<noautolink> WebSearch </noautolink>	WebSearch	WebSearch

Multiple hits

If a word is found in two or more LOOKELSEWHERE webs, a special syntax is used:

• Standard WikiWord: DefaultPreferences^{(System,Main)}
• [[Spaced wiki word]]: Default Preferences^{(System,Main)}

Create this table in Sandbox.FindElsewherePluginTest to try it out (use raw edit when pasting):

| *Test case* | *Input* | *Output<br />(if installed)* | *Expected* |
| Found elsewhere, spaced wiki word | [<nop>[Default Preferences]] | [[Default Preferences]] | %SYSTEMWEB%.DefaultPreferences |
| Found elsewhere | <nop>ProjectContributor | ProjectContributor | <nop>ProjectContributor<sup>([[%SYSTEMWEB%.ProjectContributor][%SYSTEMWEB%]],[[%MAINWEB%.ProjectContributor][%MAINWEB%]])</sup> |

Internationalization

FindElsewherePlugin handles international characters (I18N) in links, topics and webs.

Compatibility

Input	Output
FindElsewherePlugin#TopicAnchor	FindElsewherePlugin#NewFunctionalityTest
System.WebHome	WebHome
WebHome	WebHome
[[System.WebHome]]	System.WebHome
[[System.WikiWord]]	System.WikiWord
[[System.WikiWords]]	System.WikiWords
System.WikiWord	WikiWord
System.WikiWords	WikiWords
[[Main.WebSearch][This is a link to WebSearch in Main]]	This is a link to WebSearch in Main

FindElsewherePlugin Settings

Enabling and disabling the plugin globally

You can enable or disable the FindElsewherePlugin plugin sitewide (in SitePreferences), per web (in WebPreferences) or per topic by defining DISABLELOOKELSEWHERE = 1.

Where it looks to find topics

You can list other webs in which to look for topics that don't exist in the current web by defining LOOKELSEWHEREWEBS to be a comma-separated list of webs - for example, System,Main

Singular and plural topics

If the WikiWord is plural but doesn't exist, FindElsewherePlugin also looks for the singular word in other webs. You can disable this behaviour by setting DISABLEPLURALTOSINGULAR = 1. (Note this setting is for looking in other webs only (plural to singular is still automatically done in the current web, dependent on the setting in configure).

ACRONYM link preference

The LOOKELSEWHEREFORACRONYMS preference can be set to a value of none, first or all (all is default).

none means that non-forced acronyms in topics are never found elsewhere, first that they are linked only at the first occurence and all that every occurence is linked. Especially topics with many occurences of the same acronym will experience improved readability by use of the first setting.

Overriding forced local links

Even if a link refers explicitly to the current web and a topic name (for example, [[Thatweb.ThatTopic]], you can still trigger FindElsewherePlugin to look in other webs for that topic. To enable this behaviour for a web, define LOOKELSEWHEREFORLOCAL = 1 in the WebPreferences. This is particular useful when you have moved topics from one web to another, but you don't want to rewrite all the links in the source web.

Enabled for demo and testing - try it on and off

• Set LOOKELSEWHEREFORLOCAL = 1

FindElsewherePlugin Hints

• You can en- or disable this plugin for webs, topics or users, using the standard Foswiki preferences hierarchy
• You can avoid single words being looked up by using !DontLookup or <nop/>DontLookup syntax
• "Groups of webs" can use each other as lookup webs, by setting the LOOKELSEWHEREWEBS preference accordingly in their WebPreferences

Pre Dakar TWiki linking

Before Hierarchical or Nested webs were added to TWiki in 2005, topic linking rules were a little more relaxed. If you are upgrading with content that is this old, you may find some [[square backet]] links don't work any more.

You can fix this by setting the {FindElsewherePlugin}{CairoLegacyLinking} setting in configure to true.

this will link

   * [[Arth's Checklist]] to ArthsChecklist
   * [[MyNNA bugs/feature requests]] to MyNNABugsfeatureRequests
   * [[6to4.enro.net]] to 6to4enronet

Alternativly you can disable Hierarchical webs and add the forward Slash to the {NameFilter} in configure

$Foswiki::cfg{EnableHierarchicalWebs} = 0;
$Foswiki::cfg{NameFilter} = $Foswiki::cfg{NameFilter} = '[\/\\s\\*?~^\\$@%`"\'&;|<>\\[\\]#\\x00-\\x1f]';

Installation Instructions

You do not need to install anything in the browser to use this extension. The following instructions are for the administrator who installs the extension on the server.

Open configure, and open the "Extensions" section. Use "Find More Extensions" to get a list of available extensions. Select "Install".

If you have any problems, or if the extension isn't available in configure, then you can still install manually from the command-line. See http://foswiki.org/Support/ManuallyInstallingExtensions for more help.

Info

Change History:
29 Jul 2015:	(v2.5) Foswiki:Main.KennethLavrsen - Foswikitask:Item13579: Plugin now again respects NOAUTOLINK
19 Apr 2012:	(v2.4) Foswikitask:Item11778: FindElsewherePlugin breaks other plugins, prevents jquery.json.js from loading.
26 Mar 2012:	(v2.3) Foswiki:Main.SvenDowideit - Foswikitask:Item11695: add pre-Dakar linking
16 Nov 2011:	(v2.2) Foswiki:Main.GeorgeClark - Foswikitask:Item10460 - expand macros in web list, Foswikitask:Item11199 - Don't autolink wikiwords that are part of an email address. Added unit tests and addressed possible reusability issues under fastcgi or mod_perl. Replace deprecated startRenderingHandler with preRenderingHandler.
10 Jun 2010:	(v2.1) Foswiki:Main.CrawfordCurrie - major tidy-up, including removal of NOAUTOLINK no-op
25 Mar 2009:	(v2.0.1) Foswiki:Main.KennethLavrsen - fixed so it does not remove square bracket links to non-existing topics. Example in plugin topic fixed
16 Dec 2008:	(v2.0.0) Foswiki:Main.KennethLavrsen - rebranded to Foswiki
19 Dec 2007:	Steffen Poulsen - Link none, first or all standalone abbreviations (LOOKELSEWHEREFORACRONYMS option added)
18 Dec 2007:	Steffen Poulsen - Abbrev with alternative linktext found elsewhere again
25 Sep 2007:	Crawford Currie - Added redirect support, removed illegal calls, and made more efficient
20-Apr-2006:	(v1.9) - Now respects <noautolink> ... </noautolink> blocks and a new NOAUTOLINK preference flag - Michael Daum
07-Apr-2006:	(v1.8) - Replaced direct usage of %regex with :Func::getRegularExpression(), replaced some implicit scalar references with explicit $ notation - Scott Hunter
08 Apr 2005:	(v1.7) - Negated vars DISABLELOOKELSEWHERE and DISABLEPLURALTOSINGULAR can now be set per web (WebPreferences) or per topic. - Steffen Poulsen
05 Apr 2005:	(v1.6) - Bugfix: Preambles for ACRONYMS were doubled. - Steffen Poulsen
04 Apr 2005:	(v1.5) - Plugin less greedy - now leaves linktext in [[WikiWord][long links with ACRONYMS or WikiWords]] alone - Steffen Poulsen
03 Apr 2005:	(v1.4) - Documentation update. - Steffen Poulsen
02 Apr 2005:	(v1.3) - I18N-support added. New link style. WebNameAsWikiName supported - Steffen Poulsen
12-Feb-2004:	Matt Wilkie - put all of above into twikiplugins cvs, - removed "/o"'s as there may be issues with modperl
25-May-2003:	Martin Cleaver - patch to add WebNameAsWikiName
25-Sep-2002:	PeterHErnst - modified webname to show as superscript, - some other changes (chiefly "/o" regex modifiers)
15-May-2002:	Marco Carnut - patch to show webname, e.g. Main.WebHome
01 Feb 2002:	Initial version