Inconsistent Form::PATTERN

[MartinSadovy]

When I use back references in pattern rule (Form::PATTERN), it creates different behaviour on client side and server side in validation, because in Validator class, input pattern is bracked.

Example pattern: (.)\1{2,}
Different back reference:

• Client side is \1
• Server side is \2

Before I create PR, I would like to know, why pattern is bracked. There are two options: remove these bracket, or add to brackes (here, here).

use Nette\Forms\Form;

$form = new Form;
#$form->getElementPrototype()->novalidate = true;  // uncomment = validate by server side

$form->addText('name', 'Name:')
    ->addRule(
        Form::PATTERN, 
        'Please, write text with three same characters consecutively', 
        '(.)\1{2,}'
    );
$form->addSubmit('send', 'Register');
if ($form->isSuccess()) {
    echo '<h2>Form was submitted and successfully validated</h2>';

}
echo $form; // renders the form

reference bug reporting in czech forum: https://forum.nette.org/cs/25332-invert-regularniho-vyrazu#p168360

[dg]

Probably you can change (...) to (?:...) as fix.

[MartinSadovy]

I don't think so. There are missing brackets. Pattern is bracketed only in javascript validator.

PR #105

[dg]

To use (?:....) is not possible?

[MartinSadovy]

if you think (?:(.)\1{2,}), answer is no. It is still \2

[dg]

In this case documentation is wrong http://php.net/manual/en/regexp.reference.subpatterns.php

[dg]

@MartinSadovy https://3v4l.org/mlWDo

[MartinSadovy]

@dg https://3v4l.org/3BUJe

[dg]

Sorry I don't understand what you mean.

Just here put return (bool) Strings::match($control->getValue(), "\x01^(?:$pattern)\\z\x01u"); and here put return typeof arg === 'string' ? (new RegExp('^(?:' + arg + ')$')).test(val) : null;.

before I create PR, I would like to know, why pattern is bracked.

Because /^abc|def$/ is a different from /^(abc|def)$/.

[MartinSadovy]

Oh, I see. I had understood that I use ?: in pattern (eg. in ->addRule). I did not note (only one pair of breckets), my fault, sorry. O:-)

yeah, now it works correctly.

[dg]

👍

btw commit message should be changed, isn't it?

[MartinSadovy]

Validator: pattern: supports back reference to Validator: fix different behaviour client and server side while use back reference, is not too long, or actual is ok?

[dg]

Thanks!