Ta̱mpi̱let:When on basepage
This is the {{When on basepage}} meta-template. It helps other templates detect if they are on a basepage (i.e. a page whose name matches the pattern "x:x") subpage ("x:x/x") or subsubpage ("x:x/x/x").
An alternative way to detect whether a page is a subpage is to combine the parser functions #ifeq:
and #titleparts
. See Alternatives for simpler text below.
Usage
jhyuk{{When on basepage |result if on a basepage (|result if on a subpage) (|result if on a subsubpage) (|page=pagename)}}
For example, {{When on basepage|Basepage|Subpage}} on the page "User:Example" would return: Basepage
whilst on "User:Example/page" (or "User:Example/page/page", "User:Example/page/page/page", etc.) it would return: Subpage
On a subsubpage such as "User:Example/page/page" (or "User:Example/page/page/page", etc.), {{When on basepage|Basepage|Subpage|Subsubpage}} would return: Subsubpage
Use an empty parameter to specify no action for a particular type of page. {{When on basepage|Basepage|Subsubpage}} on "User:Example/page", for example, would return nothing, but would return "Subsubpage" if on "User:Example/page/page", "User:Example/page/page/page", etc. (and "Basepage" if on "User:Example").
Handling equals-signs ("=")
jhyukUse numbered parameters if their values include equals-signs ("="), i.e.
- {{When on basepage |1=basepage result (|2=subpage result) (|3=subsubpage result)}}
page parameter
jhyukThe page parameter is included for testing/demonstration. For example:
- {{When on basepage |(basepage result)|(subpage result)|page=User:Example/test}}
Regardless of where the above is placed, it will return: (subpage result)
(because "User:Example/test" is a subpage). The page doesn't have to exist.
If page is left empty (|page=
) or undefined, the page where the template is transcluded (i.e. {{PAGENAME}}
) is used.
page also accepts variables, e.g. {{When on basepage|(basepage result)|(subpage result)|page={{{page|}}} }}
Technical note
jhyukThis template detects subpages in all namespaces, including those without the MediaWiki subpage feature enabled.
Alternatives for simpler text
jhyukA subpage can be detected without using another template, by instead using the title-splitting parser function #titleparts
with #ifeq
:
{{#ifeq:{{#titleparts:{{PAGENAME}}|1|1}}|{{PAGENAME}} | [...code if on a basepage...] | [...code if on a subpage...] }}
For example, many templates can check if the page is a /sandbox version, by the similar markup with #ifeq
and #titleparts
:
- {{#ifeq: {{#titleparts:{{PAGENAME}}|1|1}} | {{PAGENAME}}
- | {{documentation}}
- | {{template sandbox notice}}
- }}
That simple logic works because Template:Template sandbox notice also checks the page name for "/sandbox" before displaying the sandbox notice; otherwise, any other subpage would show no extra text. By avoiding a template, and using a single #ifeq
, then the processing uses only +2 expansion depth levels, rather than +7 levels, and avoids "wp:exceeded template limits" inside a complex /doc page.
See also
jhyuk{{Ns has subpages}}