Extension:SectionHide

The SectionHide extension adds a [hide] link wherever there is a section heading [edit] link. This link will hide all content between that section header and the next section header of the same level, changing itself to read [show] in the process. Clicking [show] will restore the section to view.

Example
Illustration showing how each hide link conceals the related block in a nested fashion while keeping the title visible.



Mediawiki:Common.js
Add this here, or in individual skins

Versions
Added a hide/show all link at the top
 * Version 1.1

Added an option to keep the content before the first X-1 headings visible when using the hide all link. NB set to 1 to hide everything from the first heading to the end.
 * Version 1.2

added an opt-out error if installed alongside header tabs
 * Version 1.3

Added an option to use images (NB gifs only but change the javascript if you want to use pngs or jpegs) instead of/alongside words - as per requested feature
 * Version 1.4

Allow hideall to be disabled with setting less than zero - as requested

Resolved issues with display under Vector skin, resulting from renaming editsection class to mw-editsection in 1.22. Validated in 1.23.2
 * Version 1.5

Added an option on request to show the link before the title (on purpose this time) and two more to change or leave out the brackets
 * Version 1.6

Tweaked the closing div tag handling to avoid parser issues
 * Version 1.7

Author Notes
Several similar extensions were created in the past, but they are not maintained and didn't do quite what I needed.