Lua reference manual/Scribunto libraries

All Scribunto libraries are located in the table mw.

Base functions

mw.addWarning

mw.addWarning( text )

Adds a warning which is displayed above the preview when previewing an edit. text is parsed as wikitext.

mw.allToString

mw.allToString( ... )

Calls tostring() on all arguments, then concatenates them with tabs as separators.

mw.clone

mw.clone( value )

Creates a deep copy of a value. All tables (and their metatables) are reconstructed from scratch. Functions are still shared, however.

mw.executeFunction

mw.executeFunction( func )

This creates a new copy of the frame object, calls the function with that as its parameter, then calls tostring() on all results and concatenates them (no separator) and returns the resulting string.

mw.getCurrentFrame

mw.getCurrentFrame()

Returns the current frame object.

mw.incrementExpensiveFunctionCount

mw.incrementExpensiveFunctionCount()

Adds one to the "expensive parser function" count, and throws an exception if it exceeds the limit (see $wgExpensiveParserFunctionLimit).

mw.isSubsting

mw.isSubsting()

Returns true if the current #invoke is being substed, false otherwise. See Returning text for discussion on differences when substing versus not substing.

mw.loadData

mw.loadData( module )

Sometimes a module needs large tables of data; for example, a general-purpose module to convert units of measure might need a large table of recognized units and their conversion factors. And sometimes these modules will be used many times in one page. Parsing the large data table for every {{#invoke:}} can use a significant amount of time. To avoid this issue, mw.loadData() is provided.

mw.loadData works like require(), with the following differences:

The loaded module is evaluated only once per page, rather than once per {{#invoke:}} call.
The loaded module is not recorded in package.loaded.
The value returned from the loaded module must be a table. Other data types are not supported.
The returned table (and all subtables) may contain only booleans, numbers, strings, and other tables. Other data types, particularly functions, are not allowed.
The returned table (and all subtables) may not have a metatable.
All table keys must be booleans, numbers, or strings.
The table actually returned by mw.loadData() has metamethods that provide read-only access to the table returned by the module. Since it does not contain the data directly, pairs() and ipairs() will work but other methods, including #value, next(), and the functions in the Table library, will not work correctly.

The hypothetical unit-conversion module mentioned above might store its code in "Module:Convert" and its data in "Module:Convert/data", and "Module:Convert" would use local data = mw.loadData( 'Module:Convert/data' ) to efficiently load the data.

Global Modules

Modules containing tables can also be retrieved from a global repository (specifically dev.fandom.com). This uses a syntax such as:

local data = mw.loadData( 'Dev:Convert/data' )

The code above will load a table from a module stored in dev.fandom.com/wiki/Module:Convert/data (if it exists). Note: This is case sensitive.

mw.log

mw.log( ... )

Passes the arguments to mw.allToString(), then appends the resulting string to the log buffer.

In the debug console, the function print() is an alias for this function.

mw.logObject

mw.logObject( object )
mw.logObject( object, prefix )

Calls mw.dumpObject() and appends the resulting string to the log buffer. If prefix is given, it will be added to the log buffer followed by an equals sign before the serialized string is appended (i.e. the logged text will be "prefix = object-string").

Frame object

The frame object is the interface to the parameters passed to {{#invoke:}}, and to the parser.

frame.args

A table for accessing the arguments passed to the frame. For example, if a module is called from wikitext with.

{{#invoke:module|function|arg1|arg2|name=arg3}}

then frame.args[1] will return "arg1", frame.args[2] will return "arg2", and frame.args['name'] (or frame.args.name) will return "arg3". It is also possible to iterate over arguments using pairs( frame.args ) or ipairs( frame.args ).

Note that values in this table are always strings; tonumber() may be used to convert them to numbers, if necessary. Keys, however, are numbers even if explicitly supplied in the invocation: {{#invoke:module|function|1|2=2}} gives string values "1" and "2" indexed by numeric keys 1 and 2.

As in MediaWiki template invocations, named arguments will have leading and trailing whitespace removed from both the name and the value before they are passed to Lua, whereas unnamed arguments will not have whitespace stripped.

For performance reasons, frame.args is a metatable, not a real table of arguments. Argument values are requested from MediaWiki on demand. This means that most other table methods will not work correctly, including #frame.args, next( frame.args ), and the functions in the Table library.

If preprocessor syntax such as template invocations and triple-brace arguments are included within an argument to #invoke, they will be expanded before being passed to Lua. If certain special tags written in XML notation, such as <pre>, <nowiki>, <gallery> and <ref>, are included as arguments to #invoke, then these tags will be converted to "strip markers" — special strings which begin with a delete character (ASCII 127), to be replaced with HTML after they are returned from #invoke.

frame:getParent

frame:getParent()

Called on the frame created by {{#invoke:}}, returns the frame for the page that called {{#invoke:}}. Called on that frame, returns nil. This lets you just put {{#invoke:ModuleName|method}} inside a template and the parameters passed to the template (i.e. {{Hello|we|are|foo=Wikians}}) will be passed straight to the Lua module, without having to include them directly (so, you don't have to do {{#invoke:ModuleName|method|{{{1|}}}|{{{2|}}}|{{{foo|}}}}}).

Example:

Module:Hello

local p = {}

function p.hello(frame)
	return "Hello,&nbsp;" .. frame:getParent().args[1] .. "!"
end

return p

Template:Hello

{{#invoke:Hello|hello}}

Article

{{Hello|Fandom}}

This will output "Hello, Fandom!".

frame:callParserFunction

frame:callParserFunction( name, args )
frame:callParserFunction( name, ... )
frame:callParserFunction{ name = string, args = table }

Note the use of named arguments.

Call a parser function, returning an appropriate string. This is preferable to frame:preprocess, but whenever possible, native Lua functions or Scribunto library functions should be preferred to this interface.

The following calls are approximately equivalent to the indicated wikitext:

-- {{ns:0}}
frame:callParserFunction{ name = 'ns', args = 0 }

-- {{#tag:nowiki|some text}}
frame:callParserFunction{ name = '#tag', args = { 'nowiki', 'some text' } }
frame:callParserFunction( '#tag', { 'nowiki', 'some text' } )
frame:callParserFunction( '#tag', 'nowiki', 'some text' )
frame:callParserFunction( '#tag:nowiki', 'some text' )

-- {{#tag:ref|some text|name=foo|group=bar}}
frame:callParserFunction{ name = '#tag:ref', args = {
    'some text', name = 'foo', group = 'bar'
} }

Note that, as with frame:expandTemplate(), the function name and arguments are not preprocessed before being passed to the parser function.

On a wiki with the DynamicPageList3 extension installed, a DPL call would look like the following:

-- With callParserFunction, pipes need no escape but backslashes do.
local result = frame:callParserFunction{name = "#dpl:", args = {
    namespace     = "",
    uses          = "Template:Some infobox",
    include       = "{Some infobox}:param_name",
    includematch  = "/\\|\\s*param_name\\s*=\\s*(?!\\||\\s|\\Z)/m",
    secseparators = ",@@",
    format        = ",,,",
    cacheperiod   = "1209600"
} }

This outputs a string of all non-empty values of Some infobox's param_name separated by @@. For simplicity it assumes there's only one Some infobox per page and has a trailing @@.

DPLVars can also be used to get and set page variables without having to leave Lua. Note: Using Wikitext variables is always dangerous because of their scope, which is the entire page starting from point of definition. Unless precautions are taken, this can lead to bugs that are particularly difficult to track down.

frame:expandTemplate

frame:expandTemplate{ title=template, args=table }

Note the use of named args syntactic sugar; see Function calls for details.

This is transclusion. The call

frame:expandTemplate{ title = 'template', args = { 'arg1', 'arg2', ['name'] = 'arg3' } }

does roughly the same thing from Lua that {{template|arg1|arg2|name=arg3}} does in wikitext. As in transclusion, if the passed title does not contain a namespace prefix it will be assumed to be in the Template: namespace.

Note that the title and arguments are not preprocessed before being passed into the template:

-- This is roughly equivalent to wikitext like
-- {{template|{{!}}}}
frame:expandTemplate{ title = 'template', args = { '|' } }

-- This is roughly equivalent to wikitext like
-- {{template|{{((}}!{{))}}}}
frame:expandTemplate{ title = 'template', args = { '{{!}}' } }

frame:preprocess

frame:preprocess( string )
frame:preprocess{ text = string }

This expands wikitext in the context of the frame, i.e. templates, parser functions, and parameters such as {{{1}}} are expanded. Certain special tags written in XML-style notation, such as <pre>, <nowiki>, <gallery> and <ref>, will be replaced with "strip markers" — special strings which begin with a delete character (ASCII 127), to be replaced with HTML after they are returned from {{#invoke}}.

If you are expanding a single template, use frame:expandTemplate instead of trying to construct a wikitext string to pass to this method. It's faster and less prone to error if the arguments contain pipe characters or other wikimarkup.

local p = {} 

function p.hello(frame)
	-- This will preprocess the wikitext and expand the template {{foo}}
	return frame:preprocess( "'''Bold''' and ''italics'' is {{Foo}}" )
end

return p

frame:getArgument

frame:getArgument( arg )
frame:getArgument{ name = arg }

Gets an object for the specified argument, or nil if the argument is not provided.

The returned object has one method, object:expand(), that returns the expanded wikitext for the argument.

local p = {} 

function p.hello(frame)
	-- {{#invoke:ModuleName|hello|''Foo'' bar|{{Foo}}|foo={{HelloWorld}}}}
	local varOne = frame:getArgument( 1 )
	local varTwo = frame.args[2]
	local varThree = frame:getArgument( 'foo' )
	return varOne:expand() .. varTwo .. varThree:expand()
end

return p

frame:newParserValue

frame:newParserValue( text )
frame:newParserValue{ text = text }

Returns an object with one method, object:expand(), that returns the result of frame:preprocess( text ).

frame:newTemplateParserValue

frame:newTemplateParserValue{ title title, args table }

Returns an object with one method, object:expand(), that returns the result of frame:expandTemplate called with the given arguments.

frame:argumentPairs

frame:argumentPairs()

Same as pairs( frame.args ). Included for backwards compatibility.

frame:getTitle

Returns the title associated with the frame as a string.

Language library

Language codes are described at Language code. Many of MediaWiki's language codes are similar to IETF language tags, but not all MediaWiki language codes are valid IETF tags or vice versa.

{Functions documented as mw.language.name are available on the global mw.language table; functions documented as mw.language:name are methods of a language object (see mw.language.new).

Difference from MW core: mw.language.isSupportedLanguage and mw.language.isKnownLanguageTag removed, and mw.language.fetchLanguageName has been modified.

mw.language.fetchLanguageName

mw.language.fetchLanguageName( code ) mw.language.fetchLanguageName( code, inLanguage )

The full name of the language for the given language code: native name (language autonym) by default, name translated in target language if a value is given for inLanguage.

mw.language.getContentLanguage

mw.language.getContentLanguage()
mw.getContentLanguage()

Returns a new language object for the wiki's default content language.

mw.language.isValidBuiltInCode

mw.language.isValidBuiltInCode( code )

Returns true if a language code is of a valid form for the purposes of internal customisation of MediaWiki.

The code may not actually correspond to any known language.

mw.language.isValidCode

mw.language.isValidCode( code )

Returns true if a language code string is of a valid form, whether or not it exists. This includes codes which are used solely for customisation via the MediaWiki namespace.

The code may not actually correspond to any known language.

mw.language.new

mw.language.new( code )
mw.getLanguage( code )

Creates a new language object. Language objects do not have any publicly accessible properties, but they do have several methods, which are documented below.

The methods below must all use the language object (e.g. lang).

local lang = mw.language.new("en")
local ucText = lang:uc("En Taro Adun executor")
mw.log(ucText)

mw.language:getCode

lang:getCode()

Returns the language code for this language object.

mw.language:isRTL

lang:isRTL()

Returns true if the language is written right-to-left, false if it is written left-to-right.

mw.language:lc

lang:lc( s )

Converts the string to lowercase, honoring any special rules for the given language.

When the Ustring library is loaded, the mw.ustring.lower() function is implemented as a call to mw.language.getContentLanguage():lc( s ).

mw.language:lcfirst

lang:lcfirst( s )

Converts the first character of the string to lowercase, as with lang:lc().

mw.language:uc

lang:uc( s )

Converts the string to uppercase, honoring any special rules for the given language.

When the Ustring library is loaded, the mw.ustring.upper() function is implemented as a call to mw.language.getContentLanguage():uc( s ).

mw.language:ucfirst

lang:ucfirst( s )

Converts the first character of the string to uppercase, as with lang:uc().

mw.language:caseFold

lang:caseFold( s )

Converts the string to a representation appropriate for case-insensitive comparison. Note that the result may not make any sense when displayed.

mw.language:formatNum

lang:formatNum( n , nocommafy)

Formats a number with grouping and decimal separators appropriate for the given language. Given 123456.78, this may produce "123,456.78", "123.456,78", or even something like "١٢٣٬٤٥٦٫٧٨" depending on the language and wiki configuration.

With the second parameter, one can prevent the output from containing commas, as shown below:

local result = lang:formatNum(123123123, {noCommafy=true})

output: 123123123

mw.language:formatDate

lang:formatDate( format, timestamp, local )

Formats a date according to the given format string. If timestamp is omitted, the default is the current time. The value for local must be a boolean or nil; if true, the time is formatted in the server's local time rather than in UTC.

The timestamp is the actual date. It accepts dates with either a backslash or dash e.g. "2015/10/20" or "2015-10-20".

The format string and supported values for timestamp are identical to those for the #time parser function from Extension:ParserFunctions, as shown below:

--This outputs the current date with spaces between the month, day and year
lang:formatDate( 'y m d' )

--This outputs the inputted date using the specified format
lang:formatDate( 'y m d', "2015-02-01" )

Note that backslashes may need to be doubled in the Lua string where they wouldn't in wikitext:

-- This outputs a newline, where {{#time:\n}} would output a literal "n"
lang:formatDate( '\n' )

-- This outputs a literal "n", where {{#time:\\n}} would output a backslash
-- followed by the month number.
lang:formatDate( '\\n' )

-- This outputs a backslash followed by the month number, where {{#time:\\\\n}}
-- would output two backslashes followed by the month number.
lang:formatDate( '\\\\n' )

mw.language:parseFormattedNumber

lang:parseFormattedNumber( s )

This takes a number as formatted by lang:formatNum() and returns the actual number. In other words, this is basically a language-aware version of tonumber().

This library allows one to do arithmetic in multiple supported languages (simultaneously), and is better than the {{#expr}} parser function:

local n1 = "١"
local n2 = "٣"
local lang = mw.language.new("ar")
local num1 = lang:parseFormattedNumber(n1) 
local num2 = lang:parseFormattedNumber(n2) 
local total = lang:formatNum(num1 + num2)
mw.log(total)

mw.language:convertPlural

lang:convertPlural( n, ... )
lang:convertPlural( n, forms )
lang:plural( n, ... )
lang:plural( n, forms )

This chooses the appropriate grammatical form from forms (which must be a sequence table) or ... based on the number n. For example, in English you might use n .. ' ' .. lang:plural( n, 'sock', 'socks' ) or n .. ' ' .. lang:plural( n, { 'sock', 'socks' } ) to generate grammatically-correct text whether there is only 1 sock or 200 socks.

The necessary values for the sequence are language-dependent, see mw:Help:Magic words#Language-dependent word conversions for some details.

mw.language:convertGrammar

lang:convertGrammar( word, case )
lang:grammar( case, word )

Note the different parameter order between the two aliases. convertGrammar matches the order of the method of the same name on MediaWiki's Language object, while grammar matches the order of the parser function of the same name, documented at mw:Help:Magic words#Localisation.

This chooses the appropriate inflected form of word for the given inflection code case.

The possible values for word and case are language-dependent, see mw:Help:Magic words#Language-dependent word conversions for some details.

mw.language:gender

lang:gender( what, masculine, feminine, neutral )
lang:gender( what, { masculine, feminine, neutral } )

Chooses the string corresponding to the gender of what, which may be "male", "female", or a registered user name.

Site library

mw.site.currentVersion

A string holding the current version of MediaWiki.

mw.site.scriptPath

The value of $wgScriptPath.

mw.site.server

The value of $wgServer.

mw.site.siteName

The value of $wgSitename.

mw.site.stylePath

The value of $wgStylePath.

mw.site.namespaces

Table holding data for all namespaces, indexed by number.

The data available is:

id: Namespace number.
name: Local namespace name.
canonicalName: Canonical namespace name.
displayName: Set on namespace 0, the name to be used for display (since the name is often the empty string).
hasSubpages: Whether subpages are enabled for the namespace.
hasGenderDistinction: Whether the namespace has different aliases for different genders.
isCapitalized: Whether the first letter of pages in the namespace is capitalized.
isContent: Whether this is a content namespace.
isIncludable: Whether pages in the namespace can be transcluded.
isMovable: Whether pages in the namespace can be moved.
isSubject: Whether this is a subject namespace.
isTalk: Whether this is a talk namespace.
~~defaultContentModel~~(As of October 2015, this unavailable in Fandom's Scribunto): The default content model for the namespace, as a string.
aliases: List of aliases for the namespace.
subject: Reference to the corresponding subject namespace's data.
talk: Reference to the corresponding talk namespace's data.
associated: Reference to the associated namespace's data.

A metatable is also set that allows for looking up namespaces by name (localized or canonical). For example, both mw.site.namespaces[4] and mw.site.namespaces.Project will return information about the Project namespace.

mw.site.contentNamespaces

Table holding just the content namespaces, indexed by number. See mw.site.namespaces for details.

mw.site.subjectNamespaces

Table holding just the subject namespaces, indexed by number. See mw.site.namespaces for details.

mw.site.talkNamespaces

Table holding just the talk namespaces, indexed by number. See mw.site.namespaces for details.

mw.site.sassParams

Table holding SASS utility parameters, including Theme Designer color variables. This is not defined on Unified Community Platform wikis.

mw.site.stats

Table holding site statistics. Available statistics are:

pages: Number of pages in the wiki.
articles: Number of articles in the wiki.
files: Number of files in the wiki.
edits: Number of edits in the wiki.
views: Number of views in the wiki. Not available if $wgDisableCounters is set.
users: Number of users in the wiki.
activeUsers: Number of active users in the wiki.
admins: Number of users in group 'sysop' in the wiki.

mw.site.stats.pagesInCategory

mw.site.stats.pagesInCategory( category, which )

This function is expensive

Gets statistics about the category. If which is unspecified, nil, or "*", returns a table with the following properties:

all: Total pages, files, and subcategories.
subcats: Number of subcategories.
files: Number of files.
pages: Number of pages.

If which is one of the above keys, just the corresponding value is returned instead.

Each new category queried will increment the expensive function count.

mw.site.stats.pagesInNamespace

mw.site.stats.pagesInNamespace( ns )

Returns the number of pages in the given namespace (specify by number).

mw.site.stats.usersInGroup

mw.site.stats.usersInGroup( group )

Returns the number of users in the given group.

Uri library

mw.uri.encode

mw.uri.encode( s, enctype )

Percent-encodes the string. The default type, "QUERY", encodes spaces using '+' for use in query strings; "PATH" encodes spaces as %20; and "WIKI" encodes spaces as '_'.

Note that the "WIKI" format is not entirely reversable, as both spaces and underscores are encoded as '_'.

On Unified Community Platform wikis, the "WIKI" format matches the behaviour of {{urlencode|...}} - any symbol in the set [!$()*,./:;@~_-] will not be percent-encoded.

mw.uri.decode

mw.uri.decode( s, enctype )

Percent-decodes the string. The default type, "QUERY", decodes '+' to space; "PATH" does not perform any extra decoding; and "WIKI" decodes '_' to space.

mw.uri.anchorEncode

mw.uri.anchorEncode( s )

Encodes a string for use in a MediaWiki URI fragment.

mw.uri.buildQueryString

mw.uri.buildQueryString( table )

Encodes a table as a URI query string. Keys should be strings; values may be strings or numbers, sequence tables, or boolean false.

mw.uri.parseQueryString

mw.uri.parseQueryString( s )

Decodes a query string to a table. Keys in the string without values will have a value of false; keys repeated multiple times will have sequence tables as values; and others will have strings as values.

mw.uri.canonicalUrl

mw.uri.canonicalUrl( page, query )

Returns a URI object for the canonical url for a page, with optional query string/table.

mw.uri.fullUrl

mw.uri.fullUrl( page, query )

Returns a URI object for the full url for a page, with optional query string/table.

mw.uri.localUrl

mw.uri.localUrl( page, query )

Returns a URI object for the local url for a page, with optional query string/table.

mw.uri.new

mw.uri.new( s )

Constructs a new URI object for the passed string or table. See the description of URI objects for the possible fields for the table.

mw.uri.validate

mw.uri.validate( table )

Validates the passed table (or URI object). Returns a boolean indicating whether the table was valid, and on failure a string explaining what problems were found.

URI object

The URI object has the following fields, some or all of which may be nil:

protocol: String protocol/scheme
user: String user
password: String password
host: String host name
port: Integer port
path: String path
query: A table, as from mw.uri.parseQueryString
fragment: String fragment.

The following properties are also available:

userInfo: String user and password
hostPort: String host and port
authority: String user, password, host, and port
queryString: String version of the query table
relativePath: String path, query string, and fragment

tostring() will give the URI string.

Methods of the URI object are:

mw.uri:parse

uri:parse( s )

Parses a string into the current URI object. Any fields specified in the string will be replaced in the current object; fields not specified will keep their old values.

mw.uri:clone

uri:clone()

Makes a copy of the URI object.

mw.uri:extend

uri:extend( parameters )

Merges the parameters table into the object's query table.

Ustring library

The ustring library is intended to be a direct reimplementation of the standard String library, except that the methods operate on characters in UTF-8 encoded strings rather than bytes.

Most functions will raise an error if the string is not valid UTF-8; exceptions are noted.

mw.ustring.maxPatternLength

The maximum allowed lengh of a pattern, in bytes.

mw.ustring.maxStringLength

The maximum allowed lengh of a string, in bytes.

mw.ustring.byte

mw.ustring.byte( s, i, j )

Returns individual bytes; identical to string.byte().

mw.ustring.byteoffset

mw.ustring.byteoffset( s, l, i )

Returns individual the byte offset of a character in the string. The default for both l and i is 1. i may be negative, in which case it counts from the end of the string.

The character at l = 1 is the first character starting at or after byte i; the character at l = 0 is the first character starting at or before byte i. Note this may be the same character. Greater or lesser values of l are calculated relative to these.

mw.ustring.char

mw.ustring.char( ... )

Much like string.char(), except that the integers are Unicode codepoints rather than byte values.

mw.ustring.codepoint

mw.ustring.codepoint( s, i, j )

Much like string.byte(), except that the return values are codepoints and the offsets are characters rather than bytes.

mw.ustring.find

mw.ustring.find( s, pattern, init, plain )

Much like string.find(), except that the pattern is extended as described in Ustring patterns and the init offset is in characters rather than bytes.

mw.ustring.format

mw.ustring.format( format, ... )

Identical to string.format(). Widths and precisions for strings are expressed in bytes, not codepoints.

mw.ustring.gcodepoint

mw.ustring.gcodepoint( s, i, j )

Returns three values for iterating over the codepoints in the string. i defaults to 1, and j to -1. This is intended for use in the iterator form of for:

for codepoint in mw.ustring.gcodepoint( s ) do
    -- block
end

mw.ustring.gmatch

mw.ustring.gmatch( s, pattern )

Much like string.gmatch(), except that the pattern is extended as described in Ustring patterns.

mw.ustring.gsub

mw.ustring.gsub( s, pattern, repl, n )

Much like string.gsub(), except that the pattern is extended as described in Ustring patterns.

mw.ustring.isutf8

mw.ustring.isutf8( s )

Returns true if the string is valid UTF-8, false if not.

mw.ustring.len

mw.ustring.len( s )

Returns the length of the string in codepoints, or nil if the string is not valid UTF-8.

mw.ustring.lower

mw.ustring.lower( s )

Much like string.lower(), except that all characters with lowercase to uppercase definitions in Unicode are converted.

If the Language library is also loaded, this will instead call lc() on the default language object.

mw.ustring.match

mw.ustring.match( s, pattern, init )

Much like string.match(), except that the pattern is extended as described in Ustring patterns and the init offset is in characters rather than bytes.

mw.ustring.rep

mw.ustring.rep( s, n )

Identical to string.rep().

mw.ustring.sub

mw.ustring.sub( s, i, j )

Much like string.sub(), except that the offsets are characters rather than bytes.

mw.ustring.toNFC

mw.ustring.toNFC( s )

Converts the string to Normalization Form C. Returns nil if the string is not valid UTF-8.

mw.ustring.toNFD

mw.ustring.toNFD( s )

Converts the string to Normalization Form D. Returns nil if the string is not valid UTF-8.

mw.ustring.upper

mw.ustring.upper( s )

Much like string.upper(), except that all characters with uppercase to lowercase definitions in Unicode are converted.

If the Language library is also loaded, this will instead call uc() on the default language object.

Ustring patterns

Patterns in the ustring functions use the same syntax as the String library patterns. The major difference is that the character classes are redefined in terms of Unicode character properties:

%a: represents all characters with General Category "Letter".
%c: represents all characters with General Category "Control".
%d: represents all characters with General Category "Decimal Number".
%l: represents all characters with General Category "Lowercase Letter".
%p: represents all characters with General Category "Punctuation".
%s: represents all characters with General Category "Separator", plus tab, linefeed, carriage return, vertical tab, and form feed.
%u: represents all characters with General Category "Uppercase Letter".
%w: represents all characters with General Category "Letter" or "Decimal Number".
%x: adds fullwidth character versions of the hex digits.

In all cases, characters are interpreted as Unicode characters instead of bytes, so ranges such as [０-９], patterns such as %b«», and quantifiers applied to multibyte characters will work correctly. Empty captures will capture the position in code points rather than bytes.

HTML library

mw.html is a fluent interface for building complex HTML from Lua. A mw.html object can be created using mw.html.create.

Functions documented as mw.html.name are available on the global mw.html table; functions documented as mw.html:name are methods of an mw.html object (see mw.html.create).

A basic example could look like this:

local div = mw.html.create( 'div' )
div
	:attr( 'id', 'testdiv' )
	:css( 'width', '100%' )
	:wikitext( 'Some text' )
	:tag( 'hr' )
return tostring( div )
-- Output: &lt;div id="testdiv" style="width:100%;"&gt;Some text&lt;hr /&gt;&lt;/div&gt;

mw.html.create

mw.html.create( tagName, args )

Creates a new mw.html object containing a tagName html element. You can also pass an empty string as tagName in order to create an empty mw.html object.

args can be a table with the following keys:

args.selfClosing: Force the current tag to be self-closing, even if mw.html doesn't recognize it as self-closing
args.parent: Parent of the current mw.html instance (intended for internal usage)

mw.html:node

html:node( builder )

Appends a child mw.html (builder) node to the current mw.html instance.

mw.html:wikitext

html:wikitext( ... )

Appends an undetermined number of wikitext strings to the mw.html object.

mw.html:newline

html:newline()

Appends a newline to the mw.html object.

mw.html:tag

html:tag( tagName, args )

Appends a new child node with the given tagName to the builder, and returns a mw.html instance representing that new node. The args parameter is identical to that of mw.html.create

mw.html:attr

html:attr( name, value )
html:attr( table )

Set an HTML attribute with the given name and value on the node. Alternatively a table holding name->value pairs of attributes to set can be passed.

mw.html:getAttr

html:getAttr( name )

Get the value of a html attribute previously set using html:attr() with the given name.

mw.html:addClass

html:addClass( class )

Adds a class name to the node's class attribute.

mw.html:css

html:css( name, value )
html:css( table )

Set a CSS property with the given name and value on the node. Alternatively a table holding name->value pairs of properties to set can be passed.

mw.html:cssText

html:cssText( css )

Add some raw css to the node's style attribute.

mw.html:done

html:done()

Returns the parent node under which the current node was created. Like jQuery.end, this is a convenience function to allow the construction of several child nodes to be chained together into a single statement.

mw.html:allDone

html:allDone()

Like html:done(), but traverses all the way to the root node of the tree and returns it.

Text library

The text library provides some common text processing functions missing from the String library and the Ustring library. These functions are safe for use with UTF-8 strings.

mw.text.decode

mw.text.decode( s )
mw.text.decode( s, decodeNamedEntities )

Replaces HTML entities in the string with the corresponding characters.

If decodeNamedEntities is omitted or false, the only named entities recognized are '<', '>', '&', and '"'. Otherwise, the list of HTML5 named entities to recognize is loaded from PHP's get_html_translation_table function.

mw.text.encode

mw.text.encode( s )
mw.text.encode( s, charset )

Replaces characters in a string with HTML entities. Characters '<', '>', '&', '"', and the non-breaking space are replaced with the appropriate named entities; all others are replaced with numeric entities.

If charset is supplied, it should be a string as appropriate to go inside brackets in a Ustring pattern, i.e. the "set" in [set]. The default charset is '<>&"\' ' (the space at the end is the non-breaking space, U+00A0).

mw.text.jsonDecode

mw.text.jsonDecode( s )
mw.text.jsonDecode( s, flags )

Decodes a JSON string. flags is 0 or a combination (use +) of the flags mw.text.JSON_PRESERVE_KEYS and mw.text.JSON_TRY_FIXING.

Normally JSON's zero-based arrays are renumbered to Lua one-based sequence tables; to prevent this, pass mw.text.JSON_PRESERVE_KEYS.

To relax certain requirements in JSON, such as no terminal comma in arrays or objects, pass mw.text.JSON_TRY_FIXING. This is not recommended.

Limitations:

Decoded JSON arrays may not be Lua sequences if the array contains null values.
JSON objects will drop keys having null values.
It is not possible to directly tell whether the input was a JSON array or a JSON object with sequential integer keys.
A JSON object having sequential integer keys beginning with 1 will decode to the same table structure as a JSON array with the same values, despite these not being at all equivalent, unless mw.text.JSON_PRESERVE_KEYS is used.

mw.text.jsonEncode

mw.text.jsonEncode( value )
mw.text.jsonEncode( value, flags )

Encode a JSON string. Errors are raised if the passed value cannot be encoded in JSON. flags is 0 or a combination (use +) of the flags mw.text.JSON_PRESERVE_KEYS and mw.text.JSON_PRETTY.

Normally Lua one-based sequence tables are encoded as JSON zero-based arrays; when mw.text.JSON_PRESERVE_KEYS is set in flags, zero-based sequence tables are encoded as JSON arrays.

Limitations:

Empty tables are always encoded as empty arrays ([]), not empty objects ({}).
Sequence tables cannot be encoded as JSON objects without adding a "dummy" element.
To produce objects or arrays with null values, a tricky implementation of the __pairs metamethod is required.
A Lua table having sequential integer keys beginning with 0 will encode as a JSON array, the same as a Lua table having integer keys beginning with 1, unless mw.text.JSON_PRESERVE_KEYS is used.
When both a number and the string representation of that number are used as keys in the same table, behavior is unspecified.

mw.text.killMarkers

mw.text.killMarkers( s )

Removes all MediaWiki strip markers from a string.

mw.text.listToText

mw.text.listToText( list )
mw.text.listToText( list, separator, conjunction )

Join a list, prose-style. In other words, it's like table.concat() but with a different separator before the final item.

The default separator is taken from MediaWiki:comma-separator in the wiki's content language, and the default conjuction is MediaWiki:and concatenated with MediaWiki:word-separator.

Examples, using the default values for the messages:

-- Returns the empty string
mw.text.listToText( {} )

-- Returns "1"
mw.text.listToText( { 1 } )

-- Returns "1 and 2"
mw.text.listToText( { 1, 2 } )

-- Returns "1, 2, 3, 4 and 5"
mw.text.listToText( { 1, 2, 3, 4, 5 } )

-- Returns "1; 2; 3; 4 or 5"
mw.text.listToText( { 1, 2, 3, 4, 5 }, '; ', ' or ' )

mw.text.nowiki

mw.text.nowiki( s )

Replaces various characters in the string with HTML entities to prevent their interpretation as wikitext. This includes:

The following characters: '"', '&', "'", '<', '=', '>', '[', ']', '{', '|', '}'
The following characters at the start of the string or immediately after a newline: '#', '*', ':', ';', space, tab ('\t')
Blank lines will have one of the associated newline or carriage return characters escaped
"----" at the start of the string or immediately after a newline will have the first '-' escaped
"__" will have one underscore escaped
"://" will have the colon escaped
A whitespace character following "ISBN", "RFC", or "PMID" will be escaped

mw.text.split

mw.text.split( s, pattern, plain )

Splits the string into substrings at boundaries matching the Ustring pattern pattern. If plain is specified and true, pattern will be interpreted as a literal string rather than as a Lua pattern (just as with the parameter of the same name for mw.ustring.find()). Returns a table containing the substrings.

For example, mw.text.split( 'a b\tc\nd', '%s' ) would return a table { 'a', 'b', 'c', 'd' }.

If pattern matches the empty string, s will be split into individual characters.

mw.text.gsplit

mw.text.gsplit( s, pattern, plain )

Returns an iterator function that will iterate over the substrings that would be returned by the equivalent call to mw.text.split().

mw.text.tag

mw.text.tag( name, attrs, content )
mw.text.tag{ name = string, attrs = table, content string|false }

Note the use of named arguments.

Generates an HTML-style tag for name.

If attrs is given, it must be a table with string keys. String and number values are used as the value of the attribute; boolean true results in the key being output as an HTML5 valueless parameter; boolean false skips the key entirely; and anything else is an error.

If content is not given (or is nil), only the opening tag is returned. If content is boolean false, a self-closed tag is returned. Otherwise it must be a string or number, in which case that content is enclosed in the constructed opening and closing tag. Note the content is not automatically HTML-encoded; use mw.text.encode() if needed.

mw.text.trim

mw.text.trim( s )
mw.text.trim( s, charset )

Remove whitespace or other characters from the beginning and end of a string.

If charset is supplied, it should be a string as appropriate to go inside brackets in a Ustring pattern, i.e. the "set" in [set]. The default charset is ASCII whitespace, "%t%r%n%f ".

mw.text.truncate

mw.text.truncate( text, length )
mw.text.truncate( text, length, ellipsis )
mw.text.truncate( text, length, ellipsis, adjustLength )

Truncates text to the specified length, adding ellipsis if truncation was performed. If length is positive, the end of the string will be truncated; if negative, the beginning will be removed. If adjustLength is given and true, the resulting string including ellipsis will not be longer than the specified length.

The default value for ellipsis is taken from MediaWiki:ellipsis in the wiki's content language.

Examples, using the default "..." ellipsis:

-- Returns "foobarbaz"
mw.text.truncate( "foobarbaz", 9 )

-- Returns "fooba..."
mw.text.truncate( "foobarbaz", 5 )

-- Returns "...arbaz"
mw.text.truncate( "foobarbaz", -5 )

-- Returns "foo..."
mw.text.truncate( "foobarbaz", 6, nil, true )

-- Returns "foobarbaz", because that's shorter than "foobarba..."
mw.text.truncate( "foobarbaz", 8 )

mw.text.unstrip

mw.text.unstrip( s )

Replaces MediaWiki strip markers with the corresponding text. Note that the content of the strip marker do not necessarily correspond to the input, nor do they necessarily match the final page output.

Note that strip markers are typically used for a reason, and replacing them in Lua rather than allowing the parser to do so at the appropriate time may break things.

mw.text.unstripNoWiki

mw.text.unstripNoWiki( s )

Replaces MediaWiki <nowiki> strip markers with the corresponding text. Other types of strip markers are not changed.

Title library

mw.title.equals

mw.title.equals( a, b )

Test for whether two titles are equal. Note that fragments are ignored in the comparison.

mw.title.compare

mw.title.compare( a, b )

Returns -1, 0, or 1 to indicate whether the title a is less than, equal to, or greater than title b.

mw.title.getCurrentTitle

mw.title.getCurrentTitle()

Returns the title object for the current page.

mw.title.new

mw.title.new( text, namespace )
mw.title.new( id )

This function is expensive when called with a page ID

Creates a new title object. The expensive function count will be incremented if the title object was created by passing a page ID and is not for the current page and is not for a title that has already been loaded. The title referenced will be counted as linked from the current page.^[1]

If a number id is given, an object is created for the title with that page_id. If the page_id does not exist, returns nil.
If a string text is given instead, an object is created for that title (even if the page does not exist). If the text string does not specify a namespace, namespace (which may be any key found in mw.site.namespaces) will be used. If the text is not a valid title, nil is returned.

mw.title.makeTitle

mw.title.makeTitle( namespace, title, fragment, interwiki )

This function is expensive

Creates a title object with title title in namespace namespace, optionally with the specified fragment and interwiki prefix. namespace may be any key found in mw.site.namespaces. If the resulting title is not valid, returns nil. This function is expensive under the same conditions as mw.title.new(), and records a link just as does mw.title.new().

Note that mw.title.new( 'Module:Foo', 'Template' ) will create an object for the page Module:Foo, while mw.title.makeTitle( 'Template', 'Module:Foo' ) will create an object for the page Template:Module:Foo.

Note some of the properties below are methods and other are fields or variables in the title object, as shown in the example:

local titleobject = mw.title.new( 'Yoda' )
-- Doesn't use a colon
local existspage = titleobject.exists
local pagecontent

if existspage then
-- Method uses a colon}
  pagecontent = titleobject:getContent()
end

return pagecontent

Title objects

A title object has a number of properties and methods. Most of the properties are read-only.

Note that fields ending with text return titles as string values whereas the fields ending with title return title objects.

id: The page_id. 0 if the page does not exist.
interwiki: The interwiki prefix, or the empty string if none.
namespace: The namespace number.
fragment: The fragment, or the empty string. May be assigned.
nsText: The text of the namespace for the page.
subjectNsText: The text of the subject namespace for the page.
text: The title of the page, without the namespace or interwiki prefixes.
prefixedText: The title of the page, with the namespace and interwiki prefixes.
fullText: The title of the page, with the namespace and interwiki prefixes and the fragment.
rootText: If this is a subpage, the title of the root page without prefixes. Otherwise, the same as title.text.
baseText: If this is a subpage, the title of the page it is a subpage of without prefixes. Otherwise, the same as title.text.
subpageText: If this is a subpage, just the subpage name. Otherwise, the same as title.text.
canTalk: Whether the page for this title could have a talk page.
exists: Whether the page exists. Alias for fileExists for Media-namespace titles.
fileExists: Whether the file exists. For File- and Media-namespace titles, this is expensive. It will also be recorded as an image usage for File- and Media-namespace titles.
isContentPage: Whether this title is in a content namespace.
isExternal: Whether this title has an interwiki prefix.
isLocal: Whether this title is in this project. For example, on the English Wikipedia, any other Wikipedia is considered "local" while Wiktionary and such are not.
isRedirect: Whether this is the title for a page that is a redirect.
isSpecialPage: Whether this is the title for a possible special page (i.e. a page in the Special: namespace).
isSubpage: Whether this title is a subpage of some other title.
isTalkPage: Whether this is a title for a talk page.
isSubpageOf( title2 ): Whether this title is a subpage of the given title.
inNamespace( ns ): Whether this title is in the given namespace. Namespaces may be specified by anything that is a key found in mw.site.namespaces.
inNamespaces( ... ): Whether this title is in any of the given namespaces. Namespaces may be specified by anything that is a key found in mw.site.namespaces.
hasSubjectNamespace( ns ): Whether this title's subject namespace is in the given namespace. Namespaces may be specified by anything that is a key found in mw.site.namespaces.
basePageTitle: The same as mw.title.makeTitle( title.namespace, title.baseText ). This is expensive
rootPageTitle: The same as mw.title.makeTitle( title.namespace, title.rootText ). This is expensive
talkPageTitle: The same as mw.title.makeTitle( mw.site.namespaces[title.namespace].talk.id, title.text ), or nil if this title cannot have a talk page. This is expensive.
subjectPageTitle: The same as mw.title.makeTitle( mw.site.namespaces[title.namespace].subject.id, title.text ). This is expensive.
protectionLevels: The page's protection levels. This is a table with keys corresponding to each action (e.g., "edit" and "move"). The table values are arrays, the first item of which is a string containing the protection level. If the page is unprotected, either the table values or the array items will be nil. This is expensive.
subPageTitle( text ): The same as mw.title.makeTitle( title.namespace, title.text .. '/' .. text ). This is expensive.
partialUrl(): Returns title.text encoded as it would be in a URL.
fullUrl( query, proto ): Returns the full URL (with optional query table/string) for this title. proto may be specified to control the scheme of the resulting url: "http", "https", "relative" (the default), or "canonical".
localUrl( query ): Returns the local URL (with optional query table/string) for this title.
canonicalUrl( query ): Returns the canonical URL (with optional query table/string) for this title.
getContent(): Returns the (unparsed) content of the page, or nil if there is no page. The page will be recorded as a transclusion.

Title objects may be compared using Relational operators. tostring( title ) will return title.prefixedText.

Expensive properties

The properties id, isRedirect, exists, and contentModel require fetching data about the title from the database. For this reason, the expensive function count is incremented the first time one of them is accessed for a page other than the current page. Subsequent accesses of any of these properties for that page will not increment the expensive function count again.

Other properties marked as expensive will always increment the expensive function count the first time they are accessed for a page other than the current page.

Message library

This library is an interface to the localisation messages and the MediaWiki: namespace.

Functions documented as mw.message.name are available on the global mw.message table; functions documented as mw.message:name are methods of a message object (see mw.message.new).

mw.message.new

mw.message.new( key, ... )

Creates a new message object for the given message key.

The message object has no properties, but has several methods documented below.

mw.message.newFallbackSequence

mw.message.newFallbackSequence( ... )

Creates a new message object for the given messages (the first one that exists will be used).

The message object has no properties, but has several methods documented below.

mw.message.rawParam

mw.message.rawParam( value )

Wraps the value so that it will not be parsed as wikitext by msg:parse().

mw.message.numParam

mw.message.numParam( value )

Wraps the value so that it will automatically be formatted as by lang:formatNum(). Note this does not depend on the Language library actually being available.

mw.message.getDefaultLanguage

mw.message.getDefaultLanguage()

Returns a Language object for the default language.

mw.message:params

msg:params( ... )
msg:params( params )

Add parameters to the message, which may be passed as individual arguments or as a sequence table. Parameters must be numbers, strings, or the special values returned by mw.message.numParam() or mw.message.rawParam(). If a sequence table is used, parameters must be directly present in the table; references using the __index metamethod will not work.