Extension:LinkTitles

What can this extension do?
The LinkTitles extension automatically adds links to page titles to the words of a page. Whenever a page is edited and saved, the extension will look if any existing page titles occur in the text, and automatically link to the corresponding pages. This will automatically cross-reference your wiki for you.

Usage
There is not much to do. Simply install the extension, and then edit a page. When you save the page, any existing page titles that occur on the page will be converted to MediaWiki links. (See below for configuration options.)

When the checkbox "This is a minor edit" is checked, the extension will not parse the page, in order to save time when you make frequent small edits to a page. To permanently prevent the extension from adding links to a given page, you can add a Magic word to the page.

Performance impact
The extension looks for the occurrence of all existing page titles in the page content whenever a page is saved. For large wikis, this must come at the cost of a delay when a page is saved. The developer uses the extension in a wiki with about 360 content pages, where the parsing of a page adds about 0.2-0.4 seconds to the time it takes to save an edited page.

In the rare case that it messes up your page
In the past two years, the extension only very rarely added links in the wrong place, resulting in garbled content − this was exclusively when a page contained special content such as HTML passages. With the more recent versions (> 2.4), this should almost never happen.

However, if the extension does mess up your page one day, you can always revert back to a previous version using MediaWiki's 'View history' function. Just make sure to click the "This is a minor edit" checkbox at the bottom of the edit form when you revert the changes. If this box is checked, the extension will leave your page content alone.

Download & Installation
To install this extension, download the archive and extract it to the extensions directory of your MediaWiki installation. Then, add the following to LocalSettings.php:

Alternatively, if you have Git installed on your server, you can change to the extensions directory, and then clone the LinkTitles GitHub repository to your server (this will copy the entire commit history to your server).

To update a cloned git repository, change to the LinkTitles directory, then issue the command

== Configuration parameters ==

With smart mode enabled, the extension will first perform a case-sensitive search for page titles in the current page; then it will search for occurrences of the page titles in a case-insensitive way and add aliased ('piped') links. Thus, if you have a page "MediaWiki Extensions", but write "Mediawiki extensions" in your text, LinkTitles would generate a link "Mediawiki extensions", obviating the need to add dummy pages for variants of page titles with different cases.

Smart mode is enabled by default. You can disable it to increase performance of the extension.

Parse page content whenever it is edited and saved, unless 'minor edit' box is checked. This is the default mode of operation. It has the disadvantage that newly created pages won't be linked to from existing pages until those existing pages are edited and saved.

Parge page content when it is viewed. Since MediaWiki caches pages, this may or may not apply to a given page. Newly created pages will be linked to from existing ones, but the due to the caching it is impossible to predict when parsing will be triggered. Therefore this mode of operation is disabled by default.

Determines whether or not to add links to headings. By default, the extension will leave your (sub)headings untouched.

If $wgLinkTitlesPreferShortTitles is set to true, parsing will begin with shorter page titles. By default, the extension will attempt to link the longest page titles first, as these generally tend to be more specific.

Only link to page titles that have a certain minimum length. In my experience, very short titles can be ambiguous. For example, "mg" may be "milligrams" on a page, but there may be a page title "Mg" which redirects to the page "Magnesium". This settings prevents erroneous linking to very short titles by setting a minimum length. You can adjust this setting to your liking.

Exclude page titles in the array from automatic linking. You can populate this array with common words that happen to be page titles in your Wiki. For example, if for whatever reason you had a page "And" in your Wiki, every occurrence of the word "and" would be linked to this page.

To add page titles to the black list, you can use statements such as  in your. Use one of these for every page title that you want to put on the black list.

Keep in mind that a MediaWiki page title always starts with a capital letter. If you have lowercase first letters in the black list array, they will have no effect.

If set to true, do not parse the variable text of templates, i.e. in, leave the entire text between the curly brackets untouched. If set to false (default setting), the text after the pipe symbole ("|") will be parsed.

If set to true, only link the first occurrence of a title on a given page.

Restrict linking to occurrences of the page titles at the start of a word. If you want to have only the exact page titles linked, you need to set both options $wgLinkTitlesWordStartOnly and $wgLinkTitlesWordEndOnly to true. On the other hand, if you want to have all occurrences of a page title linked, even if they are in the middle of a word, you need to set both options to false.

See the above option $wgLinkTitlesWordStartOnly for an explanation.

Keep in mind that linking is case-sensitive.

== Magic word == Wiki editors can add the magic word  to a page to prevent automatic linking of page titles.

The presence of  prevents a page from being automatically linked to from other pages.

Batch processing
The extension provides two methods to batch-process all pages in a wiki: A special page and a command-line maintenance script.

Special:LinkTitles
The special page provides a simple web interface to trigger batch processing. To avoid blocking the web server for too long, the page will frequently reload itself (this can be controlled by the  configuration variable that sysops can set in the   file). For security reasons, by default only users in the 'sysop' group are allowed to view the special page (otherwise unauthorized people could trigger a parsing of your entire wiki). To allow other user groups to view the page as well, add a line  to.

Maintenance script
If you have access to a shell on the server that runs your wiki, and are allowed to execute  on the command line, you can use the extension's maintenance script. Unlike MediaWiki's built-in maintenance scripts, this resides not in the  subdirectory but in the extension's own directory (the one where you downloaded and extracted the files to).

To trigger parsing of all pages, issue: php Linktitles.cli.php You can interrupt the process by hitting  at any time.

To continue parsing at a later time, make a note of the index number of the last page that was processed (e.g., 37), and use the maintenance script with the  option (or short  ) to indicate the start index: php LinkTitles.cli.php -s 37

Issues

 * When a page title contains special characters, they may not be properly escaped in the regex, causing unexpected behavior.

Algorithm
You can browse the source code at https://github.com/bovender/LinkTitles.

The extension uses the following algorithm to convert words to links:
 * The extension is called whenever an ArticleSave event occurs.
 * It requests the page titles one by one from the wiki database, starting with the longest title.
 * For each of the page titles:
 * If the working page title from the database is different from the current page title:
 * Break the page content string into parts separated by wiki links  or by headings.
 * For each substrings that does not represent a wiki links or heading:
 * Perform a regular expression search and replace to add  to every occurrence of the title.
 * Put the substrings back together.
 * If smart mode is enabled:
 * For each substrings that does not represent a wiki links or heading:
 * Perform a case-insensitive regular expression search and replace to add  or   to every occurrence of the title.
 * Put the substrings back together.
 * Repeat with the next heading.
 * Return the converted page content.

Thus, there is a nested  loop, which may potentially be slow when there a lot of pages in the wiki, or when the page is very long. I have not noticed a delay in page processing though when using the extension in a closed-community wiki with about 130 true content pages on hosted web space.

Source code documentation
The source code documentation can be found over at the Github project pages at http://bovender.github.io/LinkTitles.

Credits
Credits to Eugene and inhan at StackOverflow for help with the regular expression.