LuaValidation

Validation library for Lua with fluent API and error message handling inspired by Respect\Validation.

Instalation

You can install it by using LuaRocks.

luarocks install validation

Usage

The fluent API of library follows the same principles of Respect\Validation.

Module import

After installing LuaValidation you can simple import it:

local v = require("validation")

Chained validation

It is possible to use validators in a chain.

v.numeric().positive().between(1, 256)

Validation functions

There are more than only one way to perform validation against you data with LuaValidation:

assert()
check()
validate()

assert()

This function validates the entire chain and produces its message.

v.numeric().positive().between(1, 256):assert(0)

The code above should produce this message:

Some rules must pass for "0"
 - "0" must be positive
 - "0" must be between "1" and "256"

check()

Works like assert() but is produces only the message of the first rule of the rule which did not pass the validation.

v.numeric().positive():check(nil)

The code above should produce this message:

"nil" must be numeric

validate()

This function returns a boolean value which says if the input is valid or not.

if v.equals("foo"):validate(input) then
  -- Do something
end

Reusable chain

Once created, you can reuse your chain anywhere:

local my_chain = v.numeric().positive().between(1, 256)

my_chain:check(first)
my_chain:check(second)
my_chain:check(third)

Custom message handler

By default you it uses error() as default message handler, but you change this behavior by defining a new messager with v.set_messager() which accepts a callback as an argument.

v.set_messager(
    function (message)
        print(">>>", message)
    end
)

Custom messages

When you use assert() and check(), you can define a custom message for you message:

v.numeric():check(nil, {message = "Something is not right"})

The above code produces this message:

Something is not right

Custom names

When you use assert() and check(), sometimes you just want to name it:

v.numeric():check(nil, {name = "Name"})