Module:Char

Lua

Code Discussion Edit History Links Link count Subpages:Documentation Tests Results Sandbox Live code All modules

This module is rated as ready for general use. It has reached a mature form and is thought to be bug-free and ready for use wherever appropriate. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing.

Note: This module is used on a lot of pages. In order not to put too much load on the servers, edits should be kept to a bare minimum. Please discuss proposed changes on the talk page first.

Editing a module causes all pages that use the module to be re-rendered. If the module is used often, this can put a lot of load on the servers since it fills up the job queue.
Keep in mind that displays produced by modules used on file description pages also show up on other wikis.

heavily used module, because of {{Tle/parm}}, {{Igen/sub}} and {{Igen/top}}.

This module checks for some critical leading characters in the passed string,
and replaces them by their decimal numeric character references,
to avoid their interpretion as wiki syntax, and returns the (altered) string.

It can be invoked directly by either "Char|substitute" or shorter by "Char|subst"
or by using the Template:Charsubst: {{Charsubst|1= }}

Note:: This module can substitute the leading characters #, *, : and ;.
Other characters, like e.g. & or < are returned-as-they-are, but their bracketing, e.g. {{Charsubst|<}}, may avoid misinterpretion.
Special characters, like | (|) and =(=) may cause problems within templates, but to substitute them by their decimal numeric character references won't help.
In some cases they can be expressed by workaround templates: | by {{!}} and = by {{=}}.
It is possible to replace the pipe | by other characters, e.g the similar looking mathematical operator ∣. This Unicode block contains also operators as −, ∕ and ∗. But neither in that block, nor among all the 1114112 Unicode characters is a substitute for the equal sign "=" known.

Code

-- This function can substitute some critical leading characters
-- by their decimal numeric character references
-- to avoid their interpretion as wiki syntax

local ncr = {}

-- function:  removes characters at the start of the string: '#', '*', ':', ';'
function ncr.subst      ( frame )
	local gpar = frame.args
	local char = ''
	if gpar then char = mw.text.trim ( gpar[1] )-- global
		else	 char = mw.text.trim ( frame )	-- local
	end
   if  mw.ustring.sub ( char, 1, 1 ) == '#' then 
         return '&#35;' .. mw.ustring.sub( char, 2, #char );
    elseif mw.ustring.sub ( char, 1, 1 ) == '*' then 
         return '&#42;' .. mw.ustring.sub( char, 2, #char );
    elseif mw.ustring.sub ( char, 1, 1 ) == ':' then 
         return '&#58;' .. mw.ustring.sub( char, 2, #char );
    elseif mw.ustring.sub ( char, 1, 1 ) == ';' then 
         return '&#59;' .. mw.ustring.sub( char, 2, #char );
    else
         return char;
    end
end -- end function subst

-- alias long function name for abbreviation 
function ncr.substitute ( frame )
	local gpar = frame.args
	return ncr.subst ( gpar[1] );
end -- end function substitute


-- function: removes characters: '"', '&', "'", '<', '=', '>', '[', ']', '{', '|', '}'
function ncr.nowiki ( frame )
	local gpar = frame.args
	return mw.text.nowiki( gpar[1] );
end -- end function nowiki

return ncr;