A collapsible element contains a toggle a reader can use to show or hide the element's content. Elements are made collapsible by adding the mw-collapsible class, or alternatively by using the {{Collapse}} template, or its variants {{Collapse top}} and {{Collapse bottom}}.
The mw-collapsible class can make any element collapsible, but tables are particularly simple to make collapsible. Adding the mw-collapsible class to a table automatically positions the toggle, and selects which parts to collapse.
A common use is to make a collapsible layout table, which always displays an introduction or summary, but hides the rest of the content from immediate view. The introduction or summary is in the first row, and the content is in subsequent rows. The content is then easily accessible by using the 'show' button.
In the examples below, the use of the class wikitable is merely for appearance; it is not needed for mw-collapsible to function.
Code entered
Output produced
{| role="presentation" class="wikitable mw-collapsible"
| <strong>Lorem ipsum</strong>
|-
| Lorem ipsum dolor sit amet
|}
Lorem ipsum
Lorem ipsum dolor sit amet
More complex data tables can also be collapsible.
Code entered
Output produced
{| class="wikitable mw-collapsible"
|+ class="nowrap" | Winter Olympic Games
|-
|
! scope="col" | City
! scope="col" | Country
|-
! scope="row" | 1994
| Lillehammer || Norway
|-
! scope="row" | 1998
| Nagano || Japan
|}
Winter Olympic Games
City
Country
1994
Lillehammer
Norway
1998
Nagano
Japan
Collapsing by default
Just using the mw-collapsible class leaves the element expanded by default, but it can be collapsed by the reader. It is also possible to make the element collapsed by default, and optionally expanded by adding other classes along with mw-collapsible. There are several methods for doing this, depending on the situations in which you want the element to collapse.
"mw-collapsed"
Adding the mw-collapsed class will cause the element to always be initially collapsed, no matter what happens around it. It is the simplest method for doing so. Using the examples above:
Code entered
Output produced
{| role="presentation" class="wikitable mw-collapsible mw-collapsed"
| <strong>Lorem ipsum</strong>
|-
| Lorem ipsum dolor sit amet
|}
Lorem ipsum
Lorem ipsum dolor sit amet
{| class="wikitable mw-collapsible mw-collapsed"
|+ class="nowrap" | Winter Olympic Games
|-
|
! scope="col" | City
! scope="col" | Country
|-
! scope="row" | 1994
| Lillehammer || Norway
|-
! scope="row" | 1998
| Nagano || Japan
|}
Winter Olympic Games
City
Country
1994
Lillehammer
Norway
1998
Nagano
Japan
"autocollapse"
Using this technique causes the page to reflow/jump around and should generally be avoided.
Adding the autocollapse class causes an element to collapse if there are 2 or more collapsible elements on the page. This threshold might be different on other projects and is customizable. The example below, therefore, collapses because there are numerous collapsible elements on this page.
Code entered
Output produced
{| role="presentation" class="wikitable mw-collapsible autocollapse"
| <strong>Lorem ipsum</strong>
|-
| Lorem ipsum dolor sit amet
|}
Lorem ipsum
Lorem ipsum dolor sit amet
"innercollapse" and "outercollapse"
Using this technique causes the page to reflow/jump around and should generally be avoided.
Using this pair of classes, it is possible to make an element collapsed by default only when it is contained within a particular outer element. An element with the mw-collapsible and innercollapse classes is collapsed by default if it is contained within an element with the outercollapse class; otherwise, it is uncollapsed by default. This is mainly useful for templates, which are often nested.
Code entered
Output produced
{| role="presentation" class="wikitable mw-collapsible innercollapse"
| This <code>innercollapse</code> element is
|-
| <em>uncollapsed</em> by default
|}
<div class="wikitable outercollapse" style="padding:1em; background:#ccc;">
This is an element with the <code>outercollapse</code> class.
{| role="presentation" class="wikitable mw-collapsible innercollapse"
| This <code>innercollapse</code> element is
|-
| <em>collapsed</em> by default
|}
</div>
This innercollapse element is
uncollapsed by default
This is an element with the outercollapse class.
This innercollapse element is
collapsed by default
Other notes
Tables with captions
A table without a caption will collapse to its first row. A table with a caption will collapse to its caption, with no rows, therefore no width. Use class="nowrap" or {{nowrap}} to keep the caption from being squeezed into a vertical column when the table is collapsed.
Code entered
Output produced
{|class="wikitable sortable mw-collapsible"
|+ class="nowrap" | Somewhat long table caption
! Name !! Score
|-
| John || 59
|-
| Bob || 72
|}
Somewhat long table caption
Name
Score
John
59
Bob
72
Next example uses {{nowrap}} where the end brackets become the wrap point. <style=max-width:Xem; will not work.
Code entered
Output produced
{|class="wikitable sortable mw-collapsible"
|+ {{nowrap|A longer table caption needs to wrap}} for cell phones, etc.
! Name !! Score
|-
| John || 59
|-
| Bob || 72
|}
A longer table caption needs to wrap for cell phones, etc.
Name
Score
John
59
Bob
72
Sortable tables
Collapsible tables can be combined with the sortable tables functionality without difficulty. However, because the hide/show button is placed with collapsible in the first header cell located or with mw-collapsible in the right header cell (this difference may change), its positioning can look a bit peculiar if the cell is not wide enough:
Code entered
Output produced
{|class="wikitable mw-collapsible sortable" style="width:5em"
<!--table width too narrow, on purpose here-->
|-
! Name !! Score
|-
| John || 59
|-
| Bob || 72
|}
Name
Score
John
59
Bob
72
A possible alternative is to add a caption over the table. See the following example.
Code entered
Output produced
{|class="wikitable sortable mw-collapsible"
|+ class="nowrap" | Caption
! Name !! Score
|-
| John || 59
|-
| Bob || 72
|}
autoCollapse=4//how many collapsible tables on the page before autocollapse works (default=2)varcollapseCaption='collapse'//text of the [hide] link (default='hide')varexpandCaption='uncollapse'//text of the [show] link (default='show')
Limitations
This functionality requires the end-user's browser to have JavaScript enabled. If JavaScript is disabled, the default behaviour is to show the content.
It doesn't work on mobile browsers (or desktop browsers in mobile mode) either.
