Module:String2/doc

This is the documentation page for Module:String2

This Lua module is used on approximately 1,460,000 pages, or roughly 15242% of all pages.
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. Consider discussing changes on the talk page before implementing them.

This module is rated as ready for general use. It has reached a mature form and is thought to be relatively bug-free and ready for use wherever appropriate. It is ready to mention on help pages and other Wikipedia resources as an option for new users to learn. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing.

The module String2 contains a number of string manipulation functions that are much less commonly used than those in Module:String. Because Module:String is cascade-protected (some of its functions are used on the Main Page), it cannot be edited or maintained by template editors, only by admins. While it is true that string-handling functions rarely need maintenance, it is useful to allow that by template editors where possible, so this module may be used by template editors to develop novel functionality.

The module contains three case-related calls that convert strings to first letter uppercase, sentence case or title case and two calls that are useful for working with substrings. There are other utility calls that strip leading zeros from padded numbers and transform text so that it is not interpreted as wikitext, and several other calls that solve specific problems for template developers such as finding the position of a piece of text on a given page.

The functions are designed with the possibility of working with text returned from Wikidata in mind. However, a call to Wikidata may return empty, so the functions should generally fail gracefully if supplied with a missing or blank input parameter, rather than throwing an error.

Functions

trim

The trim function simply trims whitespace characters from the start and end of the string.

title

The title function capitalises the first letter of each word in the text, apart from a number of short words recommended by The U.S. Government Printing Office Style Manual: a, an, the, at, by, for, in, of, on, to, up, and, as, but, or, and nor.

sentence

The sentence function finds the first letter and capitalises it, then renders the rest of the text in lower case. It works properly with text containing wiki markup. Compare {{#invoke:String2|sentence|[[action game]]}} → Action game with {{ucfirst:{{lc:[[action game]]}}}} → action game. Piped wiki-links are handled as well:

{{#invoke:String2|sentence|[[trimix (breathing gas)|trimix]]}} → Trimix

So are lists:

{{#invoke:String2 |sentence |{{hlist ||[[apples]] |[[pears]] |[[oranges]]}}}} →

ucfirst

The ucfirst function is similar to sentence; it renders the first alphabetical character in upper case, but leaves the capitalisation of the rest of the text unaltered. This is useful if the text contains proper nouns, but it will not regularise sentences that are ALLCAPS, for example. It also works with text containing piped wiki-links and with html lists.

findlast

Function findlast finds the last item in a list.
The first unnamed parameter is the list. The list is trimmed of leading and trailing whitespace
The second, optional unnamed parameter is the list separator (default = comma space). The separator is not trimmed of leading and trailing whitespace (so that leading or trailing spaces can be used).
It returns the whole list if the separator is not found.

One potential issue is that using Lua special pattern characters (^$()%.[]*+-?) as the separator will probably cause problems.

Examples
Case	Wikitext	Output
Normal usage	`{{#invoke:String2 \|findlast \| 5, 932, 992,532, 6,074,702, 6,145,291}}`	6,145,291
Space as separator	`{{#invoke:String2 \|findlast \| 5 932 992,532 6,074,702 6,145,291 }}`	5 932 992,532 6,074,702 6,145,291
One item list	`{{#invoke:String2 \|findlast \| 6,074,702 }}`	6,074,702
Separator not found	`{{#invoke:String2 \|findlast \| 5, 932, 992,532, 6,074,702, 6,145,291 \|;}}`	5, 932, 992,532, 6,074,702, 6,145,291
List missing	`{{#invoke:String2 \|findlast \|}}`

posnq

posnq (position, no quotes) returns the numerical start position of the first occurrence of one piece of text ("target") inside another ("source"). UTC characters are supported.
It returns nil by default if no match is found, or if either parameter is blank. If no match is found it can return the value of an optional "nomatch" parameter.
It takes the text to be searched in as the first unnamed parameter (or |source=), which is trimmed.
It takes the text to match as the second unnamed parameter (or |target=), which is trimmed and any double quotes " are stripped out. That allows spaces at the beginning or end of the match string to be included in a consistent manner.
It can take an optional third unnamed parameter (or |plain=), which is trimmed. If it's set to false, then the search accepts Lua pattern-matching for the target, otherwise a plain search is used.
It can take an optional fourth unnamed parameter (or |nomatch=), which is trimmed. This value is returned if no match occurs. Setting |nomatch=0 makes the output compatible with the find function in Module:String.

Examples: {{#invoke:String2 |posnq |This is a piece of text to be searched |ext}} → 21; {{#invoke:String2 |posnq |This is a piece of text to be searched |ent}} →; {{#invoke:String2 |posnq |This is a piece of text to be searched |" pie"}} → 10; {{#invoke:String2 |posnq |This is a piece of text to be searched |" ece"}} →; {{#invoke:String2 |posnq |source=This is a piece of text |target=ece}} → 13; {{#invoke:String2 |posnq |source=This is a piece of text |target=%s |plain=true}} →; {{#invoke:String2 |posnq |source=This is a piece of text |target=%s |plain=false}} → 5; {{#invoke:String2 |posnq |source=This is a piece of text |target=ece |nomatch=0}} → 13; {{#invoke:String2 |posnq |source=This is a piece of text |target=xyz |nomatch=0}} → 0; {{#invoke:String2 |posnq |This is a piece of text |" of" |true |0}} → 16; {{#invoke:String2 |posnq |This is a piece of text |" of" |true |0}} → 0; {{#invoke:String2 |posnq |source=Meet at Café Nero |target=afé}} → 10

split

The split function splits text at boundaries specified by separator and returns the chunk for the index idx (starting at 1). It can use positional parameters or named parameters (but these should not be mixed):

{{#invoke:String2 |split |text |separator |index |true/false}}
{{#invoke:String2 |split |txt=text |sep=separator |idx=index |plain=true/false}}

Any double quotes (") in the separator parameter are stripped out, which allows spaces and wikitext like ["[ to be passed. Use {{!}} for the pipe character |.

If the optional plain parameter is set to false / no / 0 then separator is treated as a Lua pattern. The default is plain=true, i.e. normal text matching.

The index parameter is optional; it defaults to the first chunk of text.

The Template:Stringsplit is a convenience wrapper for the split function.

stripZeros

The stripZeros functions finds the first number in a string of text and strips leading zeros, but retains a zero which is followed by a decimal point. For example: "0940" → "940"; "Year: 0023" → "Year: 23"; "00.12" → "0.12"

nowiki

The nowiki function ensures that a string of text is treated by the MediaWiki software as just a string, not code. It trims leading and trailing whitespace.

val2percent

The val2percent functions scans through a string, passed as either the first unnamed parameter or |txt=, and converts each number it finds into a percentage, then returns the resulting string.

one2a

The one2a function scans through a string, passed as either the first unnamed parameter or |txt=, and converts each occurrence of 'one ' into either 'a ' or 'an ', then returns the resultant string.

The Template:One2a is a convenience wrapper for the one2a function.

findpagetext

The findpagetext function returns the position of a piece of text in the wikitext source of a page. It takes up to four parameters:

First positional parameter or |text is the text to be searched for.
Optional parameter |title is the page title, defaults to the current page.
Optional parameter |plain is either true for a plain search (default), or false for a Lua pattern search.
Optional parameter |nomatch is the value returned when no match is found; default is nothing.

Examples: {{#invoke:String2 |findpagetext |text=Youghiogheny}} → 10448; {{#invoke:String2 |findpagetext |text=Youghiogheny |nomatch=not found}} → 10448; {{#invoke:String2 |findpagetext |text=Youghiogheny |title=Boston Bridge |nomatch=not found}} → 203; {{#invoke:String2 |findpagetext |text=river |title=Boston Bridge |nomatch=not found}} → not found; {{#invoke:String2 |findpagetext |text=[Rr]iver |title=Boston Bridge |plain=false |nomatch=not found}} → 216; {{#invoke:String2 |findpagetext |text=%[%[ |title=Boston Bridge |plain=f |nomatch=not found}} → 201; {{#invoke:String2 |findpagetext |text=%{%{[Cc]oord |title=Boston Bridge |plain=f |nomatch=not found}} → 2358

The search is case-sensitive, so Lua pattern matching is needed to find river or River. The last example finds {{coord and {{Coord. The penultimate example finds a wiki-link.

The Template:Findpagetext is a convenience wrapper for this function.

strip

The strip function strips the first positional parameter of the characters or pattern supplied in the second positional parameter.

matchAny

The matchAny function returns the index of the first positional parameter to match the source parameter. If the plain parameter is set to false (default true) then the search strings are Lua patterns. This can usefully be put in a switch statement to pick a switch case based on which pattern a string matches.

{{#invoke:String2|matchAny|123|abc|source=abc 124}} returns 2.

hyphen2dash

Extracted hyphen_to_dash() function from Module:Citation/CS1.

Converts a hyphen to a dash under certain conditions. The hyphen must separate like items; unlike items are returned unmodified. These forms are modified:

letter - letter (A - B)
digit - digit (4-5)
digit separator digit - digit separator digit (4.1-4.5 or 4-1-4-5)
letterdigit - letterdigit (A1-A5) (an optional separator between letter and digit is supported – a.1-a.5 or a-1-a-5)
digitletter - digitletter (5a - 5d) (an optional separator between letter and digit is supported – 5.a-5.d or 5-a-5-d)

Any other forms are returned unmodified.

The input string may be a comma- or semicolon-separated list. Semicolons are converted to commas.

{{#invoke:String2|hyphen2dash|1=1-2}} returns 1–2.

{{#invoke:String2|hyphen2dash|1=1-2; 4–10}} returns 1–2, 4–10.

Accept-this-as-written markup is supported, e.g. {{#invoke:String2|hyphen2dash|1=((1-2)); 4–10}} returns 1-2, 4–10.

By default, a normal space is inserted after the separating comma in lists. An optional second parameter allows to change this to a different character (i.e. a thin space or hair space).

Usage

{{#invoke:String2 | sentence |…}} - Capitalizes the first character and shifts the rest to lowercase
- Although similar to magic words' {{ucfirst:}} function, this call works even with piped wiki-links because it searches beyond leading brackets and other non-alphanumeric characters.
- It now also recognises when it has an html list passed to it and capitalises the first alphabetic letter beyond the list item markup (<li>) and any piped links that may be there.
{{#invoke:String2 | ucfirst |…}} - Capitalizes the first alphabetic character and leaves the rest unaltered
- Works with piped wiki-links and html lists
{{#invoke:String2 | title |…}} - Capitalizes all words, except for a, an, the, at, by, for, in, of, on, to, up, and, as, but, or, and nor.
{{#invoke:String2 | stripZeros |…}} - Removes leading padding zeros from the first number it finds in the string
{{#invoke:String2 | title |…}} - Renders the string as plain text without wikicode

Parameters

These functions take one unnamed parameter comprising (or invoking as a string) the text to be manipulated:

title
sentence
ucfirst

Examples

Input	Output
{{#invoke:String2\| ucfirst \| abcd }}	Abcd
{{#invoke:String2\| ucfirst \| abCD }}	AbCD
{{#invoke:String2\| ucfirst \| ABcd }}	ABcd
{{#invoke:String2\| ucfirst \| ABCD }}	ABCD
{{#invoke:String2\| ucfirst \| 123abcd }}	123Abcd
{{#invoke:String2\| ucfirst \| }}
{{#invoke:String2\| ucfirst \| human X chromosome }}	Human X chromosome

{{#invoke:String2\| sentence \| abcd }}	Abcd
{{#invoke:String2\| sentence \| abCD }}	Abcd
{{#invoke:String2\| sentence \| ABcd }}	Abcd
{{#invoke:String2\| sentence \| ABCD }}	Abcd
{{#invoke:String2\| sentence \| [[action game]] }}	Action game
{{#invoke:String2\| sentence \| [[trimix (breathing gas)\|trimix]] }}	Trimix
{{#invoke:String2 \| sentence \| {{#invoke:WikidataIB \|getValue \| P136 \|fetchwikidata=ALL \|onlysourced=no \|qid=Q1396889}} }}
{{#invoke:String2 \| sentence \| {{#invoke:WikidataIB \|getValue \| P106 \|fetchwikidata=ALL \|list=hlist \|qid=Q453196}} }}
{{#invoke:String2\| sentence \| }}

{{#invoke:String2\| title \| abcd }}	Abcd
{{#invoke:String2\| title \| abCD }}	Abcd
{{#invoke:String2\| title \| ABcd }}	Abcd
{{#invoke:String2\| title \| ABCD }}	Abcd
{{#invoke:String2\| title \| }}
{{#invoke:String2\| title \| the vitamins are in my fresh california raisins}}	The Vitamins Are in My Fresh California Raisins

Posnq

Template:Posnq is a convenience wrapper for the posnq function.

{{Posnq |This is a piece of text to be searched |piece of }} →
‹ The template below (Posnq) is being considered for deletion. See templates for discussion to help reach a consensus. ›

11

{{Posnq |This is a piece oftext to be searched |piece of }} →
‹ The template below (Posnq) is being considered for deletion. See templates for discussion to help reach a consensus. ›

11

{{Posnq |This is a piece of text to be searched |"piece of "}} →
‹ The template below (Posnq) is being considered for deletion. See templates for discussion to help reach a consensus. ›

11

{{Posnq |This is a piece oftext to be searched |"piece of "}} →
‹ The template below (Posnq) is being considered for deletion. See templates for discussion to help reach a consensus. ›

Stringsplit

Template:Stringsplit is a convenience wrapper for the split function.

{{Stringsplit |This is a piece of text to be split |" "}} → This
{{Stringsplit |This is a piece of text to be split |" "| 4}} → piece
{{Stringsplit |This is a piece of text to be split |x| 2}} → t to be split

Modules may return strings with | as separators like this: {{#invoke:carousel | main | name = WPDogs | switchsecs = 5 }} → Dalmatian liver stacked.jpg | Dalmatian dog stacked for show

{{Stringsplit |{{#invoke:carousel | main | name = WPDogs | switchsecs = 5 }}|{{!}}| 2}} → Dalmatian dog stacked for show

Lua patterns can allow splitting at classes of characters such as punctuation:

{{Stringsplit |Apples, pears, oranges; Cats, dogs|"%p"| 2 |false}} → pears
{{Stringsplit |Apples, pears, oranges; Cats, dogs|"%p"| 4 |false}} → Cats

Or split on anything that isn't a letter (no is treated as false):

{{Stringsplit |Apples pears oranges; Cats dogs|"%A+"| 4 |no}} → Cats

Named parameters force the trimming of leading and trailing spaces in the parameters and are generally clearer when used:

{{Stringsplit | txt=Apples pears oranges; Cats dogs | sep="%A+" | idx=3 | plain=false }} → oranges

One2a

Template:One2a is a convenience wrapper for the one2a function.

Capitalisation is kept. Aimed for usage with {{Convert}}.

{{one2a |One foot. One mile. One kilometer. One inch.One amp. one foot. one mile. one inch. Alone at last. Onely the lonely. ONE ounce. One monkey.}} →

A foot. A mile. A kilometer. An inch.An amp. a foot. a mile. an inch. Alone at last. Onely the lonely. ONE ounce. A monkey.

{{convert|1|ft|spell=on}} → one foot (zero point three zero metres)
{{one2a|{{convert|1|ft|spell=on}}}} → a foot (zero point three zero metres)
{{convert|2.54|cm|0|disp=out|spell=on}} → one inch
{{one2a|{{convert|2.54|cm|0|disp=out|spell=on}}}} → an inch

Input	Output
{{#invoke:String2\| ucfirst \| abcd }}	Abcd
{{#invoke:String2\| ucfirst \| abCD }}	AbCD
{{#invoke:String2\| ucfirst \| ABcd }}	ABcd
{{#invoke:String2\| ucfirst \| ABCD }}	ABCD
{{#invoke:String2\| ucfirst \| 123abcd }}	123Abcd
{{#invoke:String2\| ucfirst \| }}
{{#invoke:String2\| ucfirst \| human X chromosome }}	Human X chromosome

{{#invoke:String2\| sentence \| abcd }}	Abcd
{{#invoke:String2\| sentence \| abCD }}	Abcd
{{#invoke:String2\| sentence \| ABcd }}	Abcd
{{#invoke:String2\| sentence \| ABCD }}	Abcd
{{#invoke:String2\| sentence \| [[action game]] }}	Action game
{{#invoke:String2\| sentence \| [[trimix (breathing gas)\|trimix]] }}	Trimix
{{#invoke:String2 \| sentence \| {{#invoke:WikidataIB \|getValue \| P136 \|fetchwikidata=ALL \|onlysourced=no \|qid=Q1396889}} }}
{{#invoke:String2 \| sentence \| {{#invoke:WikidataIB \|getValue \| P106 \|fetchwikidata=ALL \|list=hlist \|qid=Q453196}} }}
{{#invoke:String2\| sentence \| }}

{{#invoke:String2\| title \| abcd }}	Abcd
{{#invoke:String2\| title \| abCD }}	Abcd
{{#invoke:String2\| title \| ABcd }}	Abcd
{{#invoke:String2\| title \| ABCD }}	Abcd
{{#invoke:String2\| title \| }}
{{#invoke:String2\| title \| the vitamins are in my fresh california raisins}}	The Vitamins Are in My Fresh California Raisins