Template:Blank: Difference between revisions
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Paragraph 3 | Paragraph 3 | ||
Why does that happen? It's because parser functions like {{code|#if}} strip all blanks (spaces and line breaks) that come before and after the | Why does that happen? It's because parser functions like {{code|#if}} strip all blanks (spaces and line breaks) that come before the first non-blank character, and after the last non-blank character. So the line breaks after {{code|<nowiki>{{#if: condition |</nowiki>}} are completely ignored! | ||
This can be solved with the following trick. Note the use of the empty {{code|nowiki}} tag: | This can be solved with the following trick. Note the use of the empty {{code|nowiki}} tag: | ||
Line 88: | Line 88: | ||
Paragraph 3 | Paragraph 3 | ||
</pre> | </pre> | ||
Result: | |||
Paragraph 1 {{#if: condition | {{blank}} | |||
Paragraph 2 | |||
}} | |||
Paragraph 3 | |||
</noinclude> | </noinclude> |
Latest revision as of 22:01, 2 August 2023
This empty template is useful for introducing spaces or line breaks in places where they would normally be auto-removed.
To explain why this is needed, let's look at the following code first:
Paragraph 1 {{#if: condition | Paragraph 2 }} Paragraph 3
If all the condition is met, it works fine:
Paragraph 1 Paragraph 2 Paragraph 3
But if the condition isn't met, it will produce too much empty space, like this:
Paragraph 1 Paragraph 3
Let's try to improve on this by making sure we don't introduce empty paragraphs:
Paragraph 1 {{#if: condition | Paragraph 2 }} Paragraph 3
That works exactly as desired when the condition isn't met:
Paragraph 1 Paragraph 3
But... When the condition is met, it doesn't work as expected! It does this weird thing instead:
Paragraph 1 Paragraph 2 Paragraph 3
Why does that happen? It's because parser functions like #if
strip all blanks (spaces and line breaks) that come before the first non-blank character, and after the last non-blank character. So the line breaks after {{#if: condition |
are completely ignored!
This can be solved with the following trick. Note the use of the empty nowiki
tag:
Paragraph 1 {{#if: condition | <nowiki></nowiki> Paragraph 2 }} Paragraph 3
The empty tag ends the blank auto-removal at the point it's inserted, so the line breaks that come after are not ignored.
It's tedious to write <nowiki></nowiki>
every time, so you can instead use this blank template, which can fulfill the exact same purpose:
Paragraph 1 {{#if: condition | {{blank}} Paragraph 2 }} Paragraph 3
Result:
Paragraph 1 Paragraph 2 Paragraph 3