MediaWiki: replace a tag in transclusion

Question

In a custom wiki based on MediaWiki installation 1.29, I would like to include an example in a template page.

To include this example I want both to print the code of the template and to show it. So I need to write the text down two times: one surrounded by the <pre> tag to show the text and the other one in plain text to show the interpreted example.

In order the maintain the text once only, I thought about inserting the example in a subpage like this <pre>{{SomeTemplate|SomeParameter}}</pre> and transclude this text to show it in the instruction page.

So, for the code I simply transclude {{/subpage}} while for the actual template to be shown my plan was to replace <pre></pre> with an empty string using the #replace function from https://www.mediawiki.org/wiki/Extension:ParserFunctions .

The first part worked flawlessly, the second one I am unable to make it work. The code I use for the replacement is

{{#replace:{{#replace:{{/subpage}}|<nowiki><pre></nowiki>|}}|<nowiki></pre></nowiki>|}}

But this always returns an empty string. In fact, even the part

{{#replace:{{/subpage}}|<nowiki><pre></nowiki>|}}

returns the same empty string.

Interesting enough, even the code

{{#replace:<nowiki><pre>{{SomeTemplate|SomeParameter}}</pre></nowiki>|<nowiki><pre></nowiki>|}}

returns nothing.

Is my plan feasible and I am doing something wrong in the syntax, or is it conceptually wrong and never going to work?

Thanks

Luca

The function is part of mediawiki.org/wiki/Extension:ParserFunctions . My bad not to have mentioned it: as it is built-in into MediaWiki and I enabled it ages ago, I wrongly took it for granted. Thanks. — lucamauri
Using {{#tag:pre}} unfortunately leads to the same result, apparently an empty string. — lucamauri

lucamauri lucamauri · Accepted Answer · 2019-11-02T14:48:37

After much research i found I was approaching the problem from the wrong angle.

I discovered (here https://www.mediawiki.org/wiki/Help:Templates#Usage) that the prefix msgnw: allows to transclude the text of a template without invoking it. So the easisest way to accomplish my goal is to create a subpage with only the code, without the <pre> and then using:

<code>{{msgnw:/Subpage}}</code>

to show the underlying code, and

{{/Subpage}}

to show the example.

MediaWiki: replace a tag in transclusion

1 Answers