Module:Ustring/doc
This is the documentation page for Module:Ustring
This Lua module is used in system messages, and on approximately 520,000 pages, or roughly 2122% 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 directly imports all functions from the mw.ustring
library. Documentation for each function can be found there.
The module takes an indefinite number of arguments. Arguments given as |s1=
, |s2=
, etc, are read first, and are used as strings. All remaining numerical arguments are coerced to number type if possible, and remain strings if not. If you wish for a numerical (i.e. unnamed or "|1=
", "|2=
") to remain a string, you can simply escape it by inserting \
at the beginning of the string.
Note that MediaWiki will always trim whitespace from named arguments; to give arguments with surrounding whitespace you must use unnamed parameters starting with \
.
To pass this... | Write this | Explanation |
---|---|---|
" 0123 " |
|\ 123 |
To get surrounding whitespace must use unnamed, but must precede with \ to indicate that it isn't a number.
|
"0123" |
|s1=0123 |
If you don't need to preserve whitespace use |s1= etc.
|
"0123" |
|1=\0123 |
If you don't need to preserve whitespace explicitly use |1= etc.
|
In another template, to pass its parameter {{{1}}} , preserving whitespace |
|\{{{1}}} |
Must provide the \ with unknown string input.
|
In another template, to pass its parameter {{{1}}} , stripping whitespace |
|s1={{{1}}} |
|
In another template, to pass its parameter {{{1}}} , stripping whitespace |
|1=\{{#if:1|{{{1}}}}} |
You can also wrap results in tags. All other unused arguments will be passed to
frame:extensionTag
Usage
{{#invoke:Ustring|function_name|arg1|arg2|...}}
is equivalent to mw.ustring.function_name
( arg1, arg2, ... )
Example using mw.ustring.sub
{{#invoke:Ustring|sub|s1=abcde|2|4}}
produces:
bcd
Example using mw.ustring.gsub
{{#invoke:Ustring|gsub|s1=1234|23|}}
produces:
14
Example using mw.ustring.char
&#{{#invoke:ustring|char|49|48|59}}
produces:
Example using mw.ustring.match
{{#invoke:Ustring|match|s1=abcde|s2=(c%w)}}
produces:
cd
Note: Only the first match is returned. Additional returns are omitted because mw.ustring.gsub's second return value is generally undesirable.
Example using tag arguments
{{#invoke:Ustring|match |s1={{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+% <!--enter an actual newline character to match '\n'-->%s%s%send |tag=syntaxhighlight|lang=lua}}
produces:
if not fargs.tag then
return (what(unpack(args))) -- Outside parens truncate to first result avoiding tail call
end
local tagargs = {}
for x, y in pairs(fargs) do
if not fargsused[x] then tagargs[x] = y end
end
Note that:
<syntaxhighlight lang="lua">{{#invoke:Ustring|match |s1={{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+% <!--enter an actual newline character to match '\n'-->%s%s%send}}</syntaxhighlight>
produces:
{{#invoke:Ustring|match
|s1={{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+%
<!--enter an actual newline character to match '\n'-->%s%s%send}}
Errors
Errors from accessing mw.ustring
should be maintained, e.g.:
{{#invoke:Ustring|xyzzy}}
should produce:
Script error: The function "xyzzy" does not exist.
and
{{#invoke:Ustring|maxPatternLength}}
should produce:
Script error: "maxPatternLength" is not a function.