Hirds, also known as housecarls, was a gathering of hirdmen, who functioned as the king's personal guards during the viking age and the early middle ages.

Hird is an extensible validation library for your data with sane defaults.

You can install the package via composer:

composer require asko/hird

Hird takes in an array of $fields and an array of $rules.

The key of each item in the $fields array must correspond to the the key of each item in the $rules array, so that Hird would know how to connect the two to each other.

The $rules must have a value that is a string where the rules are separated by a | character, and each rule must match the key of the implemented validator, such as len, email or one that you have implemented yourself. Additionally, each rule can take in a modifier, where the name of the rule and the modifier is separated by a : character.

For example, say we have a validator called len which takes a modifier that lets that validator validate the length of a string, in such a case we'd write that rule as len:8, which would indicate using a len validator and passing a modifier with the value 8 to it.

An example usage of Hird looks like this:

use Askonomm\Hird\Hird;

$fields = ['email' => '[email protected]'];
$rules = ['email' => 'required|email|len:5'];
$hird = new Hird($fields, $rules);

if ($hird->fails()) {
    return $hird->errors();
}

From the above example, you can see that there are two Hird methods being used such as $hird->fails() and $hird->errors(). The $hird->fails() method will run the validation and return a boolean depending on whether the validation failed or not, true if it did. The $hird->errors() method will return an array of all the errors that occured, as defined by the validators.

You can also get the first error rather than all errors by using the method $hird->firstError().

If you wish to run the validation without needing to call $hird->fails(), you can instead call $hird->validate().

You can use $hird->setFieldNames to overwrite the field names for use within the error messages, so that email could become E-mail when shown to the user. Simply provide an array where the keys are the actual field names you instantiated Hird with and the values the names you'd like used in validation messages, like so:

$hird->setFieldNames(['email' => 'E-mail']);

In some cases you want to use the same validator provided error messages, but want to mix-match them with validations you do outside of Hird. Well, for that you can use the addError method, like so:

$hird->addError("My error message goes here");

Which will prompt Hird validation to fail and show that error message.

There are a number of built-in validators available for use by default. If you want to remove a built-in validator, you can remove one using the $hird->removeValidator('rule-name') method.

The email validator validates an e-mail address, and it is registered as the email rule.

use Askonomm\Hird\Hird;

$fields = ['email' => '[email protected]'];
$rules = ['email' => 'email'];
$hird = new Hird($fields, $rules);

The len validator validates the length of a string, and it is registered as the len rule. The len validator also accepts, and requires, a modifier. A modifier can be passed to a rule by appending a color character : to it, and passing the modifier after it, like len:8.

use Askonomm\Hird\Hird;

$fields = ['password' => 'SuperSecretPassword'];
$rules = ['password' => 'len:10'];
$hird = new Hird($fields, $rules);

The required validator validates the presence of value, and it is registered as the required rule. It will pass validation if the value is set and the value is not an empty string.

use Askonomm\Hird\Hird;

$fields = ['password' => 'SuperSecretPassword'];
$rules = ['password' => 'required'];
$hird = new Hird($fields, $rules);

The date-format validator validates the string format of a date, and is registered as the date-format rule. It will pass validation if the value is set and the value is in the format specified by the rule.

use Askonomm\Hird\Hird;

$fields = ['date' => '2020-09-17'];
$rules = ['date' => 'date-format:Y-m-d'];
$hird = new Hird($fields, $rules);

You can also create your own validators, or replace existing ones if you're not happy with them.

Note: To replace an existing one, first remove the built-in validator via $hird->removeValidator('rule-name') and then add your own via $hird->registerValidator('rule-name', ValidatorClass::class).

A validator is a class that implements the Validator interface. A full example of a correct validator would look something like this:

use Asko\Hird\Validators\Validator;

class EmailValidator implements Validator
{
    public function __construct(
        private array $fields, // all fields data
        private array $fieldNames, // names of fields
    ){
    }

    /**
     * Returns a boolean `true` when given `$value` is a valid e-mail
     * address. Returns `false` otherwise.
     *
     * @param mixed $value
     * @param mixed $modifier
     * @return boolean
     */
    public function validate(string $field, mixed $value, mixed $modifier = null): bool
    {
        return filter_var($value, FILTER_VALIDATE_EMAIL);
    }

    /**
     * Composes the error message in case the validation fails.
     *
     * @param string $field
     * @param mixed $modifier
     * @return string
     */
    public function composeError(string $field, mixed $modifier = null): string
    {
        return "${field} is not a valid e-mail address.";
    }
}

You can see that there are two methods, one for validating the $value and the other for composing an error message if the validation fails. Both functions take in a $modifier argument, which will only have value if the validator is using modifiers. For example, the len validator is using modifiers to determine how long of a string should be required, by passing the rule in as len:{number-of-characters}.

Once you've created the class for your validator, you can register it by calling $hird->registerValidator('rule-name', YourValidator::class).