Module:Check for unknown parameters/doc

This is a documentation subpage for Module:Check for unknown parameters.
It may contain usage information, categories and other content that is not part of the original module page.

This Lua module is used in system messages, and on approximately 20,900,000 pages, or roughly 34% of all pages.
Changes to it can cause immediate changes to the Wikipedia user interface.
To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.

This module depends on the following other modules:

Module:If preview (sandbox)

Module:Check for unknown parameters is used to check for uses of unknown parameters in a template or module. It may be appended to a template at the end or called directly from a module.

Usage

From a template

To sort entries into a tracking category by parameter, use:

{{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|arg1|arg2|arg3|argN}}

To sort the entries into a tracking category by parameter with a preview error message, use:

{{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|preview=unknown parameter "_VALUE_"|arg1|arg2|...|argN}}

For an explicit red error message, use:

{{#invoke:Check for unknown parameters|check|unknown=<span class="error">Sorry, I don't recognize _VALUE_</span>|arg1|arg2|...|argN}}

To use Lua patterns, use:

{{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|preview=unknown parameter "_VALUE_"|arg1|arg2|...|argN|regexp1=header[%d]+|regexp2=date[1-9]}}

From a module

To call from a module, use:

local checkForUnknownParameters = require("Module:Check for unknown parameters")
local result = checkForUnknownParameters._check(validArgs, args)

Where the first set of args are the module args below and the second set of args are the parameters that are checked.

Parameters

arg1, arg2, ..., argN, are the known parameters.
Unnamed (positional) parameters can be added too: |1|2|arg1|arg2|....
Lua patterns (similar to regular expressions) usage with parameters is also supported (such as: |regexp1=header[%d]+, |regexp2=date[1-9], |regexp3=data[%d]+[abc]?). This is useful when there are many known parameters which use a systematic pattern.
|unknown= – what happens when an uknown parameter is used. Typically use either a tracking category to place pages that use unknown parameters, or an error.
|preview= – the text to be displayed when in preview mode and an unknown parameter is used.
The _VALUE_ keyword, if used, will be changed to the name of the parameter. This is useful for either sorting the entries in a tracking category, or for provide more explicit information.
|ignoreblank=1 – by default, the module makes no distinction between a defined-but-blank parameter and a non-blank parameter. That is, both unlisted |foo=x and |foo= are reported. To only track non-blank parameters use |ignoreblank=1.
|showblankpositional=1 – by default, the module ignores blank positional parameters. That is, an unlisted |2= is ignored. To include blank positional parameters in the tracking use |showblankpositional=1.

Example

{{Infobox
| above = {{{name|}}}

| label1 = Height
| data1 = {{{height|}}}

| label2 = Weight
| data2 = {{{weight|}}}

| label3 = Website
| data3 = {{{website|}}}
}}<!-- 
  end infobox, start tracking
-->{{#invoke:Check for unknown parameters|check
| unknown = {{Main other|[[Category:Some tracking category|_VALUE_]]}}
| preview = unknown parameter "_VALUE_" | height | name | website | weight 
}}

Call from within Lua code

See the end of Module:Rugby box for a simple example or Module:Infobox3cols or Module:Flag for more complicated examples.