Advertising

Placing advertisements or other banners can be useful for wikis, especially small wikis that require advertisements to generate money to offset server costs. Placing advertisements can be challenging to users who do not have an experienced understanding of MediaWiki. Some of the problems include:


 * Needing to find a way of getting the advertisement on every page of the wiki– adding the code manually to each page, possible with a template, would not be effective.
 * Security considerations– Many HTML tags and JavaScript cannot be added to pages, preventing the code from being pasted into single pages or the sitenotice. Enabling such functionality is extremely dangerous and will result in your website being hacked.
 * Keeping the code in a proper place– Someone with knowledge of MediaWiki HTML could add a banner to the relevant skin PHP file, but this would be destroyed during every upgrade. It may also be difficult for someone to know where to place the code.

Vector sidebar

 * https://gist.github.com/Inquisitor-Sasha/6759008

One of the problems with placing advertising in the Vector sidebar is that the sections are collapsible, meaning that many visitors will not see advertisements if they are not properly put it. The problem is that locking a sidebar section open requires technical server side scripting that some users might not want to do. This script places the code of the banner above the title of the section, and displays whether or not the section is expanded.

To use this script, add it to the MediaWiki:Vector.js page and change the referenced ID of the sidebar section to the ID of the section where you want to add the banner.

Howto
There are a number of existing advertisement extensions for MediaWiki that may serve as examples of how it can be done.

There are a few different ways to inject ad banners into a MediaWiki skin:
 * Edit the skin template itself (e.g.  for the Vector skin) and add the banner code in a suitable location. This is a fairly quick and easy solution, but suffers from the problem that you'll need to redo it every time you upgrade MediaWiki (or upgrade your skin, if you're using a non-standard one).
 * Find a suitable hook to inject the banner code into the skin. If you're just doing this for your own wiki, you can simply write the hook code directly into your LocalSettings.php (or into a separate PHP file that you include from there, if you prefer), but you could also turn it into a full MediaWiki extension (which basically just means, at a minimum, putting it in a separate file and adding a bit of boilerplate code).
 * Alas, finding the right hook for the job may not always be trivial. For injecting ads into the sidebar, the SkinBuildSidebar hook may be convenient; SkinAfterContent might work for footer ads, and for top ads, you could maybe (ab)use the SiteNoticeAfter hook.
 * Create a parser tag extension that allows you to add a custom tag like  to your pages to inject the ad banner code at that location. Straightforward, but requires you put the tag on any page that you want ads on (or in an interface message, if you can find a suitable one; tip: try appending the parameter   to URLs to see which messages are used where).
 * Find a suitably located interface message which is treated as raw HTML, and put your ad code there directly. Alas, there aren't many such messages, and the trend is towards getting rid of the few that are left.
 * For ads that can be injected with JavaScript only, you can simply put the code in MediaWiki:Common.js (or in the appropriate skin-specific JS page).