Preg replace callback

Question

I am trying to work out how to pop an optional group into a preg_replace_callback but I am having trouble matching the + character

Here is the code I have this far

$pattern=preg_replace_callback('~:(?P<_param>[Aa-zZ0-9_\-]+)(?:(P<_mod>[^/]))?~',

    function($matches)
    {
        print_r($matches);
        $key=$matches[1];
        return '(?<'.$matches['_param'].'>'.$matches['_mod'].')';
    }
    ,$subject);

This generates the following pattern

/category/(?<foo>)/(?<baz>.)+/(?<bar>.)+/(?<harry>.)+/foo

For the following string

/category/:foo/:baz.+/:bar.+/:harry.+/foo

As you can see it's carrying over the . but not the plus, essentially I would like it to carry (into the named _mod capture group) any modifier that I append to a :variable.

I am not very good at regex so I'm amazed to have gotten this far and any help on my quest would be greatly appreciated

That's quite an unhelpful comment, perhaps offering an alternative would be more helpful? — J.Doe, Sep 18 '15 at 12:07

Toto · Accepted Answer · 2016-05-22T08:52:33.347

Add a quantifier after the group _mod:

$pattern=preg_replace_callback('~:(?P<_param>[Aa-zZ0-9_\-]+)(?:(?P<_mod>[^/]+))?~',function($matches){
//                                                                  here ___^

question: what do you think [Aa-zZ] matches?

I guess you want [A-Za-z0-9_\-]+ or [\w-]

Furthermore, preg_replace would suffice here:

$pattern = preg_replace('~:([\w-]+)(?:([^/]*))?~', "(?<$1>$2)", $subject);

Preg replace callback

1 Answers1