Data Validator Filters

Filters are an essential part of the data validation process, as they allow you to alter how fields and their values are validated.

Filters can be easily added to a field thanks to the addFilter method. It is also very easy to create custom fields to extend the capabilities of the data validator to meet your needs.

Built-in Filters

Filter	Description	Apply On
DoNotExistInDB	Checks if a field's value does not exist in a table's column of the database	Values
ExistsInDB	Checks if a field's value exists in a table's column of the database	Values
In	Checks if a field's value exists in a list of options	Values
InFloatRange	Checks if a field's value is comprised between two floating point values	Values
InIntRange	Checks if a field's value is comprised between two integer values	Values
IsOfType	Checks if a field's value is of a specific type (boolean, string, int, etc)	Values
LogicOr	This filter is a container for other filters. It will be considered valid if any of the contained filters is deemed valid.	Values
MatchFilter	Checks if a field's value matches those of one or more other fields	Values
Path	Checks if a field's value is matching the path of an existing file	Values
RegExp	Checks if a field's value is matching a regular expression	Values
RequiredIfNotEmpty	Checks that a field contains a value if another field is not empty	Values
Unique	Checks that a field, most likely repeatable, contains only unique values	Fields

Writing a Custom Filter

Let's say you want to write a filter to check if a field's value is even.

Here's how you would do that:

use chsxf\MFX\DataValidator\AbstractFilter;

class IsEven extends AbstractFilter {

    public function __construct(string $message = NULL) {
        if ($message === NULL) {
            $message = "The value of the '%s' field must be even";
        }
        parent::__construct($message);
    }

    public function validate(string $fieldName, mixed $value, int $atIndex = -1, bool $silent = false): bool {
        if (!is_numeric($value) || intvalue($value) % 2 != 0) {
            $this->emitMessage($fieldName);
            return false;
        }
        return true;
    }

}