Transclusions

Transclusions are a feature in many wiki platforms, including MediaWiki, which allows the inclusion of content from one page into another. This feature is particularly useful for maintaining consistency and reducing redundancy across a wiki. When a transclusion is made, the content from the source page is embedded directly into the target page, ensuring that any updates to the source page are automatically reflected in all pages that transclude it.

Transclusions can be of two main types: templates and parser functions. Templates are reusable blocks of text that can include variables and other templates. They are often used for standardizing formats, such as infoboxes on article pages. Parser functions, on the other hand, are special commands that generate dynamic content. Examples include the current date and time, or the number of articles in the wiki.

The syntax for transcluding a template typically involves using double curly braces, like {{TemplateName}}. For parser functions, the syntax usually involves double curly braces with a hash symbol, like {{#time: Y-m-d}}. Transclusions can also be nested, meaning a template can include another template, and so on.

While transclusions are powerful tools for maintaining consistency, they can also introduce complexity and potential issues. For instance, excessive nesting can lead to performance problems, and circular transclusions (where two templates include each other) can cause errors. Therefore, it is important to use transclusions judiciously and to understand their implications.