Module:Lua call
 | This module is rated as alpha. It is ready for third-party input, and may be used on a few pages to see if problems arise, but should be watched. Suggestions for new features or changes in their input and output mechanisms are welcome. |
This module allows you to call any one single preinstalled Lua function, so that you don't need to write a module for one desired feature.
Usage
Main
{{#invoke:LuaCall|main|arbitrary variables|parameters|functioncall}}
The arbitrary variables are any key of your choice = any value of your choice. Values are interpreted as strings unless tonumber(value) isn't nil, i.e. numbers should be converted to the numeric type. No effort is made to interpret tables.
The parameters all begin with reserved_, which arbitrary variable should use.
reserved_returnsets which output from the function you want, and defaults to 1. For example, setting it to 2 for mw.ustring.gsub will return the number of replacements made.reserved_debug- nonzero value forces display of a not particularly useful debug text
The functioncall is written as some.function.name(a,b,c) where some.function.name means something in the Extension:Scribunto/Lua reference manual and a,b,c are the arbitrary variable names you've chosen.
Examples
Main
{{#invoke:LuaCall|main|a=test |b=7|string.rep(a,b)}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|pattern=(%a)|replace=%1.|string=I can't get no satisfaction|mw.ustring.gsub(string,pattern,replace)|reserved_return=1}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|pattern=(%a)|replace=%1.|string=I can't get no satisfaction|mw.ustring.gsub(string,pattern,replace)|reserved_return=2}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|value=1.4512|math.ceil(value)}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|value=1.4512|math.modf(value)}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|value=1.4512|math.modf(value)|reserved_return=2}}→ Lua error at line 26: attempt to call field '?' (a nil value).{{#invoke:LuaCall|main|mw.text.nowiki(s)|s={{URL|1=https://www.Amazon.com/}}}}→ Lua error at line 26: attempt to call field '?' (a nil value).
Call
{{#invoke:LuaCall|call|string.format|%04x|127}}→ Script error: The function "call" does not exist.{{#invoke:LuaCall|call|math.modf|1.4512}}→ Script error: The function "call" does not exist.{{#invoke:LuaCall|call|math.modf|1.4512|return=2}}→ Script error: The function "call" does not exist.
Errors
The module may generate script errors — whenever your call is not valid Lua code, you see the error you would normally have. For example,
{{#invoke:LuaCall|main|value=1.4512|math.fmod(value)}} →
Lua error at line 26: attempt to call field '?' (a nil value).
because the second value is lacking. No effort is made to trap these.
local p={}
function p.main(frame)
local parent=frame.getParent(frame) or {}
for k,v in pairs(parent.args or {}) do
_G[k]=v -- transfer every parameter directly to the global variable table
end
for k,v in pairs(frame.args or {}) do
_G[k]=v -- transfer every parameter directly to the global variable table
end
--- Alas Scribunto does NOT implement coroutines, according to
--- http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#string.format
--- this will not stop us from trying to implement one single lousy function call
if _G[1] then
local reserved_function,reserved_contents=mw.ustring.match(_G[1],"^(%s*%a[^%s%(]*)%(([^%)]*)%)%s*$")
local reserved_value={}
local reserved_counter=0
if reserved_contents then
repeat
reserved_counter=reserved_counter+1
reserved_value[reserved_counter]=mw.ustring.match(reserved_contents,"([^%,]+)")
reserved_contents=mw.ustring.match(reserved_contents,"[^%,]+,(.*)$")
until not reserved_contents
end
end
return _G[reserved_function](unpack(reserved_contents or {}))
end
return p