CakePHP失败的自定义规则验证（正则表达式）

Question

I'm following a Lynda.com course for CakePHP 2.4.0 and per the material the following code should work but fails with the latter error message:

    public $validate = array(
        'publication_name' => array(
            'words' => array(
                'rule' => array('custom', '/([\w.-]+ )+[\w+.-]/'),
                'message' => 'The publication name can only contain letters, numbers and spaces.',
            )
        ),
    );

"preg_match(): Delimiter must not be alphanumeric or backslash [CORE/Cake/Model/Validator/CakeValidationRule.php, line 281]".

Per my searching, the regex should work as it is using a non-alphanumeric delimiter (/). I'm quite perplexed to say the least.

The only way I have been able to get it to successfully save the record is by removing the custom validation rule (which is not the desired result for a variety of reasons).

Any insight on why this is failing validation? I've diff'd my code against that of the author's exercise files and am not sure what I'm (most likely) over looking...

Thank you in advance for your time and insight. I truly appreciate it.

Source Code for Model, View and Controllers: http://tny.cz/0a995577

Answer 1

As pointed out in the comments, the regex itself is syntactically correct, so it won't cause such an error. As you figured it was a typo in a different rule causing the problem.

However the rule also won't validate as expected ( http://regex101.com/r/dA0pH9 ), as the regex matches one or more words (including . and - ) separated by a single space, followed by a single word char (again including . and - ). Also it allows to prepend and append arbitrary chars, as it doesn't make use of ^ and $ .

To make it match your requirements

one word, multiple words, including numbers and spaces

try something like this:

/^(\w ?)+(?<! )$/

That would match one or more words (which may consist of numbers only, and may be only 1 char in length), separated by a space, not allowing a trailing space.

Though it would also match something like 1 2 3 4 5 ( http://regex101.com/r/kK3jG9/ ), which might not be applicable, so you may want to refine it, for example by requiring at least 1 letter per word, with a minimum length of 3 chars:

/^((?=\d*[a-z])\w{3,} ?)+(?<! )$/i

A quick breakdown:

(
  (?=\d*[a-z])  # the word must contain at least one letter
  \w{3,} ?      # a word with at least 3 chars, optionally followed by a space
)+              # one or more times
(?<! )          # no trailing space allowed