Template:Ifnoerror then show
 | This template is used on approximately 569,000 pages, or roughly 1% of all pages. To avoid major disruption and server load, any changes should be tested in the template's /sandbox or /testcases subpages, or in your own user subpage. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
This template tests whether the first unnamed parameter contains an error message and returns
- the value of the first parameter prefixed by the third parameter value, and suffixed by the fourth parameter value, if there is no error;
- the value of the second unnamed parameter, if given, or the first parameter value itself, if there is an error.
This is useful when the first parameter is an {{#invoke: }} of a Lua module that may return an error. Because it uses the {{#invoke: }} just once, it simplifies the coding of infoboxes, for example.
It can be used for adding tracking categories in templates, where showing the module's error message is undesirable.
Usage
- {{#invoke:Infobox mapframe|auto}} called with improper coordinates
{{ifnoerror then show |{{#invoke:Infobox mapframe|auto|onByDefault=yes|coordinates=10, 30}} |ERROR|PREFIX|SUFFIX}}→ERROR
- {{#invoke:Infobox mapframe|auto}} call that produces no errors
{{ifnoerror then show |{{#invoke:Infobox mapframe|auto|onByDefault=yes}} |ERROR|PREFIX|SUFFIX}}→PREFIX{{invoke:Infobox mapframe|...}}SUFFIX
See also
- {{Iferror then show}} – similar template with inverted logic