1 <?php
 2 
 3 namespace Docolight\Http;
 4 
 5 use Docolight\Support\Set;
 6 
 7 /**
 8  * HTTP Headers.
 9  *
10  * ```php
11  * $headers = new Docolight\Http\Headers;
12  *
13  * $headers->set('My-Header-Index', 'My header value');
14  * ```
15  *
16  * @author Krisan Alfa Timur <krisanalfa@docotel.co.id>
17  */
18 class Headers extends Set
19 {
20     /**
21      * Special-case HTTP headers that are otherwise unidentifiable as HTTP headers.
22      * Typically, HTTP headers in the $_SERVER array will be prefixed with
23      * `HTTP_` or `X_`. These are not so we list them here for later reference.
24      *
25      * @var array
26      */
27     protected static $special = array(
28         'CONTENT_TYPE',
29         'CONTENT_LENGTH',
30         'PHP_AUTH_USER',
31         'PHP_AUTH_PW',
32         'PHP_AUTH_DIGEST',
33         'AUTH_TYPE',
34     );
35 
36     /**
37      * Extract HTTP headers from an array of data (e.g. $_SERVER).
38      *
39      * @param array $data
40      *
41      * @return array
42      */
43     public static function extract($data)
44     {
45         $results = array();
46 
47         foreach ($data as $key => $value) {
48             $key = strtoupper($key);
49 
50             if (strpos($key, 'X_') === 0 or strpos($key, 'HTTP_') === 0 or in_array($key, static::$special)) {
51                 if ($key !== 'HTTP_CONTENT_LENGTH') {
52                     $results[$key] = $value;
53                 }
54             }
55         }
56 
57         return $results;
58     }
59 
60     /**
61      * Transform header name into canonical form.
62      *
63      * @param string $key
64      *
65      * @return string
66      */
67     protected function normalizeKey($key)
68     {
69         $key = strtolower($key);
70         $key = str_replace(array('-', '_'), ' ', $key);
71         $key = preg_replace('#^http #', '', $key);
72         $key = ucwords($key);
73         $key = str_replace(' ', '-', $key);
74 
75         return $key;
76     }
77 }
78