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

This Lua module is used in MediaWiki:Perfcachedts, and on approximately 1,390,000 pages, or roughly 2% 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:

This module, migrated from origins in Module:Hatnote, provides functionality for formatting links for display, including that powering the ((format link)) template.

It can pretty-format section links with the section symbol ("§") and appropriate whitespace, it automatically escapes category and file names with the colon trick, and includes functionality for italicizing the page or section name, and for detecting and categorizing results that produce red links.

Use from wikitext[edit]

The functions in this module cannot be used directly from #invoke, and must be used through templates instead. Please see Template:Format link for documentation on usage of that template.

Use from other Lua modules[edit]

To load this module from another Lua module, use the following code:

local mFormatLink = require('Module:Format link')

You can then use the functions as documented below.

_formatLink[edit]

mFormatLink._formatLink{
    link = 'Link',
    display = 'Display',
    target = 'Target',
    italicizePage = true,
    italicizeSection = true,
    categorizeMissing = 'Pages using formatted red links'
}

Formats link as a wikilink. Categories and files are automatically escaped with the colon trick, and links to sections are automatically formatted as page § section, rather than the MediaWiki default of page#section.

Several options modify the output:

If the display value is present, then it will be used as a display value. Any manual piping (using the ((!)) magic word or similar) present in link will be overridden by the display value if present.
If the target value is present, then it will override link as a target, but the result will still be displayed using either the value from display, or the result of formatting link.
If italicizePage is true, then the page portion of the link is italicized if present.
If italicizeSection is true, then the section portion of the link is italicized if present.
If categorizeMissing is a non-empty string, then that value is used as a category name, and that category will be applied if the resulting target of the link (no matter whether through link or through target) doesn't exist.

Examples: mFormatLink._formatLink{link = 'Foo#Bar'} → [[:Foo#Bar|Foo § Bar]] → Foo § Bar; mFormatLink._formatLink{link = 'Baz', display = 'Qux'} → [[:Baz|Qux]] → Qux; mFormatLink._formatLink{link = 'Foo|Bar', display = 'Baz'} → [[:Foo|Baz]] → Baz; mFormatLink._formatLink{link = '#Foo', target = 'Example#Foo'} → [[:Example#Foo|§ Foo]] → § Foo; mFormatLink._formatLink{link = 'The Lord of the Rings#Plot', italicizePage = true} → [[:The Lord of the Rings#Plot|''The Lord of the Rings'' § Plot]] → The Lord of the Rings § Plot; mFormatLink._formatLink{link = 'Cybercrime Prevention Act of 2012#Disini v. Secretary of Justice', italicizeSection = true} → [[:Cybercrime Prevention Act of 2012#Disini v. Secretary of Justice|Cybercrime Prevention Act of 2012 § ''Disini v. Secretary of Justice'']] → Cybercrime Prevention Act of 2012 § Disini v. Secretary of Justice; mFormatLink._formatLink{link = 'Nonexistent page', categorizeMissing = 'Example'} → [[:Nonexistent page]][[Category:Example]] → Nonexistent page; mFormatLink._formatLink{link = 'Existing', categorizeMissing = 'Example'} → [[:Existing]] → Existing

formatPages[edit]

mFormatLink.formatPages(options, pages)

This derived function is useful for lists that format many links. It formats an array of pages using the _formatLink function, and returns the result as an array. Options in the options table are applied, and use the same names as the options for _formatLink.

Example: mFormatLink.formatPages({categorizeMissing = 'Example'}, {'Foo#Bar', 'Nonexistent page'}) → {'[[:Foo#Bar|Foo § Bar]]', '[[:Nonexistent page]][[Category:Example]]'}

Errors[edit]

If _formatLink is used and neither a link nor a target argument is provided, then the module will produce an error message instead of its usual output, as it cannot then produce valid output.

You can solve this error by providing appropriate parameters to _formatLink, or you may want to ensure that a more descriptive error is provided by a downstream template or module when it would otherwise call _formatLink with inadequate arguments.