फलकम्:If empty

विकिपीडिया, कश्चन स्वतन्त्रः विश्वकोशः
Jump to navigation Jump to search
Template documentation[view] [edit] [history] [purge]

स्क्रिप्ट त्रुटि: "High-use" ऐसा कोई मॉड्यूल नहीं है।

This is the {{If empty}} template.

  • Update 2014 Dec 23: This template used to only take 9 parameters. This limit has been removed.

This template is used inside other templates. It takes any number of parameters and returns the first found to be defined and non-empty. If none is found, nothing is returned. Typical usage is like this:

{{If empty |{{{logo|}}} |{{{image|}}} |{{{picture|}}} |default.svg}}
("Return {{{logo|}}} if it has a value; else {{{image|}}} if it has a value; else {{{picture|}}} if it has a value; else return "default.svg".")

This returns the first of the parameters logo, image and picture that is defined and non-empty, otherwise "default.svg".

Rationale[सम्पादयतु]

The MediaWiki parameter default function doesn't return the default value for empty parameters. That is, {{{logo|default.svg}}} does not return "default.svg" if the template was called like this: {{template|logo=}}.

The usual workaround for a single parameter is:

{{#if:{{{logo|}}} |{{{logo}}} |default.svg}}
("If {{{logo}}} has a value, return it, else return "default.svg".")

But this becomes complex when several parameters are to be checked:

{{#if:{{{logo|}}} |{{{logo}}} |{{#if:{{{image|}}} |{{{image}}} |{{#if:{{{picture|}}} |{{{picture}}} |default.svg}} }} }}
("If {{{logo}}} has a value, return it; else if {{{image}}} has a value, return that; else if {{{picture}}} has a value, return that; else return "default.svg".")

In these cases, {{if empty}} produces the simpler syntax (as above):

{{if empty |{{{logo|}}} |{{{image|}}} |{{{picture|}}} |default.svg}}

Piping[सम्पादयतु]

Parameters used with {{if empty}} must be piped – i.e. include the vertical bar (pipe) symbol ("|") as a trailing character – so that empty or undefined parameters aren't treated as text and returned incorrectly. Hence, for example, {{{logo|}}}, {{{image|}}} and {{{picture|}}} rather than {{{logo}}}, {{{image}}} and {{{picture}}} in the above examples.

Examples[सम्पादयतु]

स्क्रिप्ट त्रुटि: "aligned table" ऐसा कोई मॉड्यूल नहीं है।

See also[सम्पादयतु]

"https://sa.wikipedia.org/w/index.php?title=फलकम्:If_empty&oldid=426622" इत्यस्माद् प्रतिप्राप्तम्