I'd like to be able to write a MediaWiki extension that uses template parameters, but the parser doesn't seem able to handle this.
As an example, let's say that I set up a page [[Template:Politician]] that creates an external link to some information about a U.S. congressional district.
I would invoke this template as follows: {{Politician | name = John Doe | district=NY01 }}
The text of the template itself, which generates the link, is as follows:
*[http://www.politician.com?district=%7B%7B%7Bdistrict%7D%7D%7D District information for {{{name}}}]
If, however, the "district" parameter is omitted, I wouldn't want this line to be created at all. There's a messy way to set up if-then decisions using existing template mechanisms, but I'd rather be able to use something like the following as the text of the template:
<district_info> name={{{name}}} district={{{district}}} </district_info>
Then I could write a MediaWiki extension that handles the logical branching. The extension could also handle some other processing, such as pulling in summary data about that congressional district from an another website's external APIs.
At present, however, there doesn't seem to be any way to pass the {{{name}}} and {{{district}}} parameters into a MediaWiki extension. Instead of getting the VALUES of those parameters, I just get the string "{{{name}}}" and "{{{district}}}".
Solutions, anyone?
--Sheldon Rampton