Codeigniter's regex match

Though there is no regex_match() method in CodeIgniter validation library, It's not listed in the CI User Guide.

Per @Limon's comment:

There is a bug in CodeIgniter with the pipe |, it breaks the regex.

CodeIgniter uses | as a separator between validate methods.

Therefore, to prevent from breaking the regex, you could create a callback method in your Controller to validate the input by matching the regex:

public function regex_check($str){    if (preg_match("/^(?:'[A-Za-z](([\._\-][A-Za-z0-9])|[A-Za-z0-9])*[a-z0-9_]*')$/", $str))    {        $this->form_validation->set_message('regex_check', 'The %s field is not valid!');        return FALSE;    }    else    {        return TRUE;    }}

Then add the validation rule, as follows:

$this->form_validation->set_rules('username', 'Nombre de usuario', 'required|min_length[2]|max_length[15]|callback_regex_check|is_unique[user.username]');

You might provide rules as an array :

$this->form_validation->set_rules('username', 'Nombre de usuario', array('required', 'min_length[2]', 'max_length[15]', 'regex_match[/^(?:\'[A-z](([\._\-][A-z0-9])|[A-z0-9])*[a-z0-9_]*\')$/]', 'is_unique[user.username]'));

This way regex with pipes won't crash