Preg替换回调

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

Answer 1

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);