Editing Module:Sandbox/Toohool

local p = {}

local function trim(s)
    return mw.ustring.gsub(s, "^%s*(.-)%s*$", "%1")    
end

function p.makeWrapper(func, opts)
    opts = opts or {}
    
    local nullableArgNames = {}
    for i, v in ipairs(opts.nullable or {}) do
        nullableArgNames[v] = true
    end
    
    local noTrimArgNames = {}
    for i, v in ipairs(opts.notrim or opts.noTrim or {}) do
        noTrimArgNames[v] = true
    end
    
    return function(frame)
        local origArgs
        if frame == mw.getCurrentFrame() then
            -- We're being called via #invoke. If the invoking template passed any args, use
            -- them. Otherwise, use the args that were passed into the template.
            origArgs = frame:getParent().args
            for k, v in pairs(frame.args) do
                origArgs = frame.args
                break
            end
        else
            -- We're being called from another module or from the debug console, so assume
            -- the args are passed in directly.
            origArgs = frame
        end
 
        local args = {}
        setmetatable(args, {
            -- ParserFunctions considers the empty string to be false, so to preserve the previous 
            -- behavior of the template, change any empty arguments to nil, so Lua will consider
            -- them false too.
            __index = function(t, k)
                local v = origArgs[k]
                
                if v and not noTrimArgNames[k] then
                    v = trim(v)
                end
                
                if v ~= '' or nullableArgNames[k] then
                    return v
                else
                    return nil
                end
            end,
        
            __pairs = function(t)
                local nextFunc = function(tbl, k)
                    local v
                    repeat
                        k = next(origArgs, k)
                        v = args[k]
                    until (not k) or v
                    return k, v
                end
                return nextFunc, t, nil
            end,
            
            __ipairs = function(t)
                -- TODO 
            end
        })
 
        return func(args)
    end
end

return p