The InterMap (also called InterWiki in some other wikis) is a system for defining links between WikiWikiWeb sites that was first developed by UseMod and Meatball (see UseMod:InterWiki and Meatball:InterWiki). The method is to use a word shortcut that stands for a defined path. InterMap links have the form MapPrefix:PagePath, where the host prefix is converted to a partial URL based on entries in the site's intermap.txt and localmap.txt files.

The default intermap.txt

The default intermap.txt distributed with PmWiki (in the scripts/ directory) includes the following InterMap entries:

 PmWiki:     http://www.pmwiki.org/wiki/PmWiki/ 
 Cookbook:   http://www.pmwiki.org/wiki/Cookbook/ 
 Wiki:       http://www.c2.com/cgi/wiki? 
 UseMod:     http://www.usemod.com/cgi-bin/wiki.pl? 
 Meatball:   http://www.usemod.com/cgi-bin/mb.pl? 
 Wikipedia:  http://en.wikipedia.org/wiki/ 
 PITS:       http://www.pmwiki.org/wiki/PITS/ 
 PmL10n:     http://www.pmwiki.org/wiki/Localization/
 Path:

The page Site.InterMap?

You can map your own prefixes in your local page Site.InterMap?.

Thus, "PmWiki:Variables" becomes "http://www.pmwiki.org/wiki/PmWiki/" + "Variables," a link to the PmWiki.Variables page on the official PmWiki web site, Wiki:FrontPage is a link to the front page of the first WikiWikiWeb, and Wikipedia:Stonehenge takes you to the Wikipedia article about the famous megaliths in England.

Usage in a wiki page

Like other links, you can use the double-bracket syntax to get different link text:

If you want to link just to what the intermap says (e.g. http://www.wikipedia.com/wiki/ for Wikipedia), then do [[Wikipedia:. | Wikipedia's main page]], which produces Wikipedia's main page. Note the . (period) after the Map: reference.

The special Path: InterMap entry can be used to create "relative urls" in links.

Custom InterMap prefixes

The actual set of InterMap links at any site is defined by the site administrator via the Site.InterMap? page and the local/localmap.txt file.

An intermap entry takes the following format:

MapPrefix:      http://example.com/partial/url/

The InterMap entry can be for any of the link schemes supported by PmWiki.
You can create your own InterMap links by doing one or more of the following:

• Modify the page called Site.InterMap? and place entries like the ones above in it.
• Create a file called local/localmap.txt and place entries like the ones above in it.
• In a WikiFarm installation you can create a file called local/farmmap.txt and there place entries like the ones above in it. These prefixes will be common to all the wikis in the farm.
• Ensure that there is a space after the colon.

Do not edit the file scripts/intermap.txt directly! If you do, you'll lose your changes when you upgrade PmWiki.

Variables and InterMap links

It's possible to use variables within your InterMap entries. The following entries create ThisWiki: and ThisPage: shortcuts:

ThisWiki:        $ScriptUrl
ThisPage:        {$PageUrl}

You can also define InterMap entries where the text of the entry is substituted into the middle of the URL. Just include '$1' in the URL where you want the substitution to take place. For example:

would cause Jargon:F/feature-creep to be converted to http://catb.org/~esr/jargon/html/F/feature-creep.html.

Tips and tricks

It is possible to document your intermap prefixes directly in the page Site.InterMap?. The extra text will not cause a performance penalty, nor will it break the definition of prefixes. However, be aware that anything matching a line starting with a word and a colon (:) will be considered to define a prefix.

The order in which various sources are checked for definitions of prefixes is controlled by the variable $InterMapFiles. Currently the precedence (highest to lowest is as follows):

• local/localmap.txt
• $SiteGroup.InterMap
• $FarmD/local/farmmap.txt
• $FarmD/scripts/intermap.txt

      $LinkFunctions['PmWikiHome:'] = 'LinkIMap';
      $IMap['PmWikiHome:'] = 'http://pmwiki.org/wiki/$1';