With the multitude of single sign-on modules out there for Drupal, it's easy to miss the fact that Drupal has a built-in single sign on mechanism already. No modules, no configuration, just 20 easy lines of PHP in your site's settings.php file. This solution works for a lot of clients, but the set of requirements is pretty specific as to when you can use this approach. This includes:

• The sites sharing a single log-in must be on the same domain. For example:
• www.example.com
• forums.example.com
• subsite.example.com
• You must be using MySQL.
• Your sites must be on the same hardware cluster to be able to query each other's databases.

If your site fits within those requirements, you're on your way to simple, efficient, and easy Single Sign-on!

The concept for this single sign-on approach is based around Drupal's ability to prefix database tables. As you may know, you can run multiple Drupal sites on the same MySQL database. However, most sites are not configured this way, each site is given it's own dedicated database. Drupal's table prefixing can be combined with MySQL's ability to query across databases to make a simple "shared table" across multiple sites. Then you just need to set a cookie domain so that the two sites share session information and you're done!

Drupal's theming system offers developers and designers a flexible way to override default HTML output when specific portions of the page are rendered. Everything from the name of the currently logged in user to the HTML markup of the entire page can be customized by a plugin "theme".

Unfortunately, this system can be its own worst enemy. Themes are very powerful, but in many cases they're the only place where specific output can be changed without hacking core. Because of this, themes on highly customized production sites can easily turn into code-monsters, carrying the weight of making 'Drupal' look like 'My Awesome Site.'

This can make maintenance difficult, and it also makes sharing these tweaks with other Drupal developers tricky. In fact, some downloadable modules also come with instructions on how to modify a theme to 'complete' the module's work. Wouldn't it be great if certain re-usable theme overrides could be packaged up and distributed as part of any Drupal? As it turns out, that is possible. In this article, we'll be exploring two ways to do it: a tweaky, hacky approach for Drupal 5, and a clean and elegant approach that's only possible in Drupal 6.

During a recent Lullboat podcast we mentioned a new feature in Drupal 6 that allows you replace any string in Drupal without using Locale module (thanks Moshe!). Faithful podcast listener Rob Loach took it upon himself to write the String Overrides module that lets you accomplish this task with ease in Drupal 6.

While Lullabots were lamenting the fact that this feature was never in Drupal 5, we realized that it actually could be accomplished. An hour after undertaking the project, the patch was submitted to the String Overrides queue and committed shortly afterwards.

String Overrides accomplishes this in Drupal 5 by imitating the Locale module, and without hitting the database (since variables are cached and pulled up on every request anyway). Since this essentially a hack for Drupal 5, you cannot combine it with Locale module or languages other than English. Here's the key code that makes this possible:

Introduction

Most people who use forum systems such as vBulletin or PHPBB are used to having lots of extra features that Drupal core's forums don't contain by default, including private messages, smilies, and BBcode. While all of those are available as contributed modules, there are two "must-have" forum features that are a bit trickier, since they deal with access control: private forums, and forum moderators.

Drupal core tends to have an "all or nothing" approach to these issues. Either a particular role can access all content on the site, or they can access none of it. Either a particular role can administer all forums, or they can administer none of them. Luckily, though, Drupal provides a number of hooks so that contributed modules can add in their own robust access handling.

This article will look at three modules that enhance forum privileges, and compare and contrast them: Forum Access, Taxonomy Access Control, and Taxonomy Access Control Lite.