Template inheritance (Community Wishlist/W120)

Description

Let's say, we have an infobox for musicians. Now, we create a page for a musician of a specific music genre and add our infobox. However, we would want to add a field to the infobox specific to our genre, which is currently missing in the infobox and would not be used for other genres. Of course, we can

Copy the infobox source code and create a new infobox with this and the new field
Add the field as optional to the existing infobox

While both solutions work, they are not ideal

Creating a new template: When changing either the existing infobox or the new one, they get out of sync
Adding optional fields to the existing template: The template can get cluttered pretty quick with every genre adding their genre-specific optional fields and make it easy to lose the plot

A solution would be to use inheritance like in programming. You create a new template and define which template it inherits/extends, so you only have to add the additional, genre-specific fields.

Of course, the infobox is only an example and this would work in other contexts as well.

Assigned focus area

Unassigned

Type of wish

Feature request