Question

I try to parse url with a regular expression in order to capture element, but i don’t know how to do. Samples of URL :

• location-cottage with $path_ => array( type => cottage )
• location-cottage-p1 with $path_ => array( type => cottage, page => p1 )
• location-cottage-my-region-r01 with $path_ => array( type => cottage, region => r01 )
• location-cottage-my-department-d01 with $path_ => array( type => cottage, department => d01)
• location-cottage-my-department-d01-p1 with $path_ => array( type => cottage, department => d01, page => p1)

I would like to do this with one regular expression, but i don’t know to do this, i try with this :

$expression = '#location-(?P<type>cottage|house)[a-z,-]*';
$expression.= '(?P<region>r[0-9]{2}|)';
$expression.= '(?P<department>d[0-9]{2}\)';
$expression.= '(?P<town>v[0-9]{5}|)';
$expression.= '[-]*(?P<page>[p0-9]*)$#';
preg_match($expression, $_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'], $path_);

Someone can help me ?

In a second part, if it’s possible I would like to keep only 01 and not d01, only 1 and not p1, as this :

• location-cottage-my-department-d01-p1 with $path_ => array( type => cottage, department => 01, page => 1)

Answer 1

Firstly, use #x to make your regex more readable. Then use ? behind each capture group that can be optional:

$expression = <<< RX 
    #
      location-(?P<type>cottage|house)[a-z,-]*
      (?P<region> r[0-9]{2}|)   ?
      (?P<department> d[0-9]{2})   ?
      (?P<town> v[0-9]{5}|)   ?
      [-]*(?P<page> [p0-9]*)   ?
    $#x
RX;

And if you don’t want to capture the d for example, then move it out of the named capture group, and wrap it in (?: )? instead.