How to customise the Regex validation messages in a Zend\Form keeping them reusable?

Question

The default validation error message for Regex is

"The input does not match against pattern '%pattern%'"

I can replace it by a custom one like

"Please make an input according to the pattern '%pattern%'"

But then I still have a not really user-friendly message with the internal regex in it. I also can write

"Only capital letters are allowed"

But in this case I need to write a new message for every single regex field.

Is it possible / How to create own, but still flexible/reusable/parameterizable messages?

An example of what I want:

public function getInputFilterSpecification()
{
    return [
        'foo' => [
            'validators' => [
                [
                    'name' => 'Regex',
                    'options' => [
                        'pattern' => '/^[A-Z0-9:]*$/',
                        'pattern_user_friendly' => 'capital letters, numbers, and colons',
                        'message' => 'The input may only contain the following characters: %pattern_user_friendly%.'
                    ]
                ],
            ]
        ],
        'bar' => [
            'validators' => [
                [
                    'name' => 'Regex',
                    'options' => [
                        // new pattern
                        'pattern' => '/^[A-Z~:\\\\]*$/',
                        // new user friendly pattern description
                        'pattern_user_friendly' => 'capital letters, tildes, colons, and backslashes',
                        // still the same message
                        'message' => 'The input may only contain the following characters: %pattern_user_friendly%.'
                    ]
                ],
            ]
        ],
    ];
}

automatix · Accepted Answer · 2016-11-12T11:53:10.183

The solution is to create a custom Validator (extending the Regex), to extend there the list of messageVariables, and to add the logic for setting the value as a property:

class Regex extends ZendRegex
{
    protected $patternUserFriendly;

    public function __construct($pattern)
    {
        // s. https://github.com/zendframework/zend-validator/blob/master/src/Regex.php#L34-L36
        $this->messageVariables['patternUserFriendly'] = 'patternUserFriendly';
        $this->messageTemplates[self::NOT_MATCH] =
            'The input may only contain the following characters: %patternUserFriendly%.'
        ;
        parent::__construct($pattern);
        if (array_key_exists('patternUserFriendly', $pattern)) {
            $this->patternUserFriendly = $pattern['patternUserFriendly'];
        }
    }
}

class MyFieldset extends ZendFieldset implements InputFilterProviderInterface
{
    ...
    public function init()
    {
        parent::init();
        $this->add(
            [
                'type' => 'text',
                'name' => 'foo',
                'options' => [
                    'label' => _('foo')
                ]
            ]);
        $this->add(
            [
                'type' => 'text',
                'name' => 'bar',
                'options' => [
                    'label' => _('bar')
                ]
            ]);
    }
    public function getInputFilterSpecification()
    {
        return [
            'bar' => [
                'validators' => [
                    [
                        'name' => 'MyNamespace\Validator\Regex',
                        'options' => [
                            'pattern' => '/^[a-zA-z]*$/',
                            'patternUserFriendly' => '"a-z", "A-Z"'
                        ]
                    ]
                ]
            ]
        ];
    }
}

Isn't this a bit overkill to build your own Regex validator just to show the string you set with `patternUserFriendly`, while you could have just overwritten the message and use the value of the `patternUserFriendly` within your message? — Kwido, Nov 11 '16 at 08:18
Thank you for your input! I've just updated the code, in order to avoid writing the same message every time. But you are right, it might be a bit to much effort for an optimization of one line of code. It's only worth in a case with a lot of similar `Regex` validated fields, that only vary in the `pattern` part of the validation message. — automatix, Nov 12 '16 at 12:06

How to customise the Regex validation messages in a Zend\Form keeping them reusable?

1 Answers1