Module:LuaCall

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.

The module may generate script errors -- whenever your call isn't valid Lua code, you see the error you would normally have. For example,

{{#invoke:LuaCall|main|value=1.4512|math.fmod(value)}} will produce Template:Script error because the second value is lacking. No effort is made to trap these.

Usage

{{#invoke:LuaCall|main|''arbitrary variables''|''parameters''|''function''}}

The arbitrary variables are any key of your choice = any value of your choice. Values are interpreted as strings unless tonumber(value) is not NaN - 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_return sets 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 function 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

{{#invoke:LuaCall|main|a=test |b=7|string.rep(a,b)}}

test test test test test test test 

{{#invoke:LuaCall|main|pattern=(%a)|replace=%1.|string=I can't get no satisfaction|mw.ustring.gsub(string,pattern,replace)|reserved_return=1}}

I. c.a.n.'t. g.e.t. n.o. s.a.t.i.s.f.a.c.t.i.o.n.

{{#invoke:LuaCall|main|pattern=(%a)|replace=%1.|string=I can't get no satisfaction|mw.ustring.gsub(string,pattern,replace)|reserved_return=2}}

22

{{#invoke:LuaCall|main|value=1.4512|math.ceil(value)}}

2

{{#invoke:LuaCall|main|value=1.4512|math.modf(value)}}

1

{{#invoke:LuaCall|main|value=1.4512|math.modf(value)|reserved_return=2}}

0.4512

{{#invoke:LuaCall|main|mw.text.nowiki(s)|s={{URL|1=https://www.Amazon.com/}}}}

<span class="url">[https://www.Amazon.com/ www<wbr/>.amazon<wbr/>.com]</span>

---

local p={}

function p.main(frame)
    local parent=frame.getParent(frame) or {}
    local reserved_value={}
    local reserved_function,reserved_contents
    for k,v in pairs(parent.args or {}) do
        if tonumber(v)~=NaN then v=tonumber(v) end
        _G[k]=v -- transfer every parameter directly to the global variable table
        -- debuglog=debuglog..k.."="..v.."</nowiki><br /><nowiki>"
    end
    for k,v in pairs(frame.args or {}) do
        if tonumber(v)~=NaN then v=tonumber(v) end       
        _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
        reserved_function,reserved_contents=mw.ustring.match(_G[1],"^%s*(%a[^%s%(]*)%(([^%)]*)%)%s*$")
    end
    if reserved_contents then
        local reserved_counter=0
        repeat
            reserved_counter=reserved_counter+1
            reserved_value[reserved_counter]=_G[mw.ustring.match(reserved_contents,"([^%,]+)")]
            reserved_contents=mw.ustring.match(reserved_contents,"[^%,]+,(.*)$")
        until not reserved_contents
    end
    local reserved_arraypart=_G
    while mw.ustring.match(reserved_function,"%.") do
        reserved_functionpart,reserved_function=mw.ustring.match(reserved_function,"^(%a[^%.]*)%.(.*)$")
        reserved_arraypart=reserved_arraypart[reserved_functionpart]
    end
    local reserved_call=reserved_arraypart[reserved_function]
    if type(reserved_call)~="function" then
        return tostring(reserved_call)
    elseif reserved_debug or not reserved_function then return mw.text.nowiki(debuglog)
    else reserved_output={reserved_call(unpack(reserved_value))}
        return reserved_output[reserved_return or 1]
    end
end
return p