CODEWITHSUNDEEP
luaarguments
Darryl Quinn
Darryl Quinn

Reputation: 53

lua 5.1 how to use loadstring to call a function that is not in global namespace AND requires arguments

trying to create a wrapper function to call various validation functions. The validation functions are not in the global namespace AND they require parameters. I'm using Lua 5.1 and trying to get the loadstring() function to work but not having any luck.

-- wrapper function
local function validateField(funcName, funcArg, errorTable)
    local vres
    local functionCall = loadstring("return " .. funcName .. "(...)")

    vres = functionCall(funcArg)

    if vres~=true then
        table.insert(errorTable, vres)
        return false
    end
    return true
end

calling code:

local result = validateField("valid.nameField" , data.name, errors)

Upvotes: 2

Views: 514

Answers (1)

Nicol Bolas
Nicol Bolas

Reputation: 473232

If all you want to do is call a function, giving it some arguments, and checking the return value, then you don't need to use loadstring at all. It's a simple matter of just passing the function as a parameter to validateField.

local function validateField(errorTable, func, ...)
    local res = func(...);

    if res ~= true then
        table.insert(errorTable, res)
        return false
    end
    return true
end

And then calling it appropriately (note that I changed the order of parameters):

local result = validateField(errors, valid.nameField, data.name)

Upvotes: 3

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