Validator

Validator#

Arokettu\ArithmeticParser\Validator can be used to catch situations that are valid for the parser but will definitely fail in calculator, namely:

  • Undefined variable. A list of available variables is unknown during parsing time

  • Undefined function. A list of functions may be not final during parsing time, this allows users to have dynamic functions if needed

  • Not enough arguments passed to a function. Same reasons, function list may be dynamic

Validator\Warning#

Arokettu\ArithmeticParser\Validator\Warning

An object describing a validator warning. There are 3 warnings currently:

  • MissingVariablesWarning

  • MissingFunctionsWarning

  • MissingFunctionArgumentsWarning

<?php

use Arokettu\ArithmeticParser\Validator;

$warnings = Validator::validate(/* ... */);

foreach ($warnings as $warning) {
    // check which warning is it
    $funcsMissing = $warning instanceof Validator\MissingFunctionsWarning;

    // get message describing the warning
    $errorMessage = $warning->getMessage();

    // convert to an exception
    throw $warning->toException();
}

Methods#

Validator exposes several methods that do a single thing but tailored to different possible use semantics

Validator::validate()#

Returns an array of Arokettu\ArithmeticParser\Validator\Warning:

<?php

use Arokettu\ArithmeticParser\Config;
use Arokettu\ArithmeticParser\Parser;
use Arokettu\ArithmeticParser\Validator;

$config = Config::default();
$parsed = (new Parser($config))->parse('a + 1');

$warnings = Validator::validate($parsed, $config, ['a']);
$isValid = $warnings === [];

foreach ($warnings as $warning) {
    // ...
}

Validator::isValid()#

Returns a boolean, can optionally populate a list of warnings:

<?php

use Arokettu\ArithmeticParser\Config;
use Arokettu\ArithmeticParser\Parser;
use Arokettu\ArithmeticParser\Validator;

$config = Config::default();
$parsed = (new Parser($config))->parse('a + 1');

$isValid = Validator::isValid($parsed, $config, ['a'], $warnings);

foreach ($warnings as $warning) {
    // ...
}

Validator::assertValid()#

Throws an exception when the input is not valid:

<?php

declare(strict_types=1);

require __DIR__ . '/../vendor/autoload.php';

use Arokettu\ArithmeticParser\Config;
use Arokettu\ArithmeticParser\Exceptions\ValidationException;
use Arokettu\ArithmeticParser\Parser;
use Arokettu\ArithmeticParser\Validator;

$config = Config::default();
$parsed = (new Parser($config))->parse('a + 1');

try {
    Validator::assertValid($parsed, $config, ['a']);
    $isValid = true;
} catch (ValidationException $e) {
    $isValid = false;
}