Template:Ifnotempty
Script error: No such module "Template translation". With this template #if can be used in a way such that it does not strip spaces and newlines from the "then" and "else" part. For evaluating the condition spaces and newlines are stripped like with ParserFunctions.
Usage
{{ifnotempty|x| p | q }}gives " p "{{ifnotempty|| p | q }}gives " q "
Compare:
{{#if:x| p | q }}gives "p"
Note that, unlike parser functions, templates require writing equals signs in values of unnamed parameters as {{=}}
For full substitution, simply use Template:Cnw or Template:Cnw. If the condition contains a parser function, template, or variable, that should be substituted too. Optionally the "then" or "else" part can also be substituted.
Expansion depth limit
13 levels allowed:
{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|a}}}}}}}}}}}}}}}}}}}}}}}}}} gives {{Expansion depth limit exceeded|x|{{Expansion depth limit exceeded|x|{{Expansion depth limit exceeded|x|a}}}}}}
{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|{{ifnotempty|x|a}}}}}}}}}}}}}}}}}}}}}}}}}}}} gives {{Expansion depth limit exceeded|x|{{Expansion depth limit exceeded|x|{{Expansion depth limit exceeded|x|{{Expansion depth limit exceeded|x|a}}}}}}}}
Internal technical details
For evaluating the condition the template uses the actual parser functions; however, not directly with p and q, because this strips spaces and newlines from them, but with index values 1 and 2. The result can be 1, 2, or, only in the case of #ifexpr, an error message. Using a switch these are converted to p1, p2, and if/errmsg, respectively. The template with the applicable name is called (Template:P1, Template:P2, or Template:If/errmsg), with as parameters p, q, and {{{2}}}. Templates p1 and p2 ignore {{{2}}}; template if/errmsg is only called in the case of #ifexpr, in the case of a wrong expression {{{2}}}; it ignores p and q and uses {{{2}}} for display in the error message.
Conditions
#if:
Condition: string not empty.
