git.m6w6.name Git - m6w6/seekat/blob - lib/API/Links.php

   1 <?php
   2
   3 namespace seekat\API;
   4
   5 use http\Header;
   6 use http\Params;
   7 use http\QueryString;
   8 use http\Url;
   9
  10 class Links implements \Serializable
  11 {
  12         /**
  13          * Parsed "Link" relations
  14          * @var \http\Params
  15          */
  16         private $params;
  17
  18         /**
  19          * Parsed "Link" relations
  20          * @var array
  21          */
  22         private $relations = [];
  23
  24         /**
  25          * Parse the hypermedia link header
  26          *
  27          * @var string $header_value The value of the "Link" header
  28          */
  29         function __construct(Header $links) {
  30                 if (strcasecmp($links->name, "Link")) {
  31                         throw new \UnexpectedValueException("Expected 'Link' header, got: '{$links->name}'");
  32                 }
  33                 $this->unserialize($links->value);
  34         }
  35
  36         function __toString() : string {
  37                 return $this->serialize();
  38         }
  39
  40         function serialize() {
  41                 return (string) $this->params;
  42         }
  43
  44         function unserialize($links) {
  45                 $this->params = new Params($links, ",", ";", "=",
  46                         Params::PARSE_RFC5988 | Params::PARSE_ESCAPED);
  47                 if ($this->params->params) {
  48                         foreach ($this->params->params as $link => $param) {
  49                                 $this->relations[$param["arguments"]["rel"]] = new Url($link);
  50                         }
  51                 }
  52         }
  53
  54         /**
  55          * Receive the link header's parsed relations
  56          *
  57          * @return array
  58          */
  59         function getRelations() : array {
  60                 return $this->relations;
  61         }
  62
  63         /**
  64          * Get the URL of the link's "next" relation
  65          *
  66          * Returns the link's "last" relation if it exists and "next" is not set.
  67          *
  68          * @return \http\Url
  69          */
  70         function getNext() {
  71                 if (isset($this->relations["next"])) {
  72                         return $this->relations["next"];
  73                 }
  74                 if (isset($this->relations["last"])) {
  75                         return $this->relations["last"];
  76                 }
  77                 return null;
  78         }
  79
  80         /**
  81          * Get the URL of the link's "prev" relation
  82          *
  83          * Returns the link's "first" relation if it exists and "prev" is not set.
  84          *
  85          * @return \http\Url
  86          */
  87         function getPrev() {
  88                 if (isset($this->relations["prev"])) {
  89                         return $this->relations["prev"];
  90                 }
  91                 if (isset($this->relations["first"])) {
  92                         return $this->relations["first"];
  93                 }
  94                 return null;
  95         }
  96
  97         /**
  98          * Get the URL of the link's "last" relation
  99          *
 100          * @return \http\Url
 101          */
 102         function getLast() {
 103                 if (isset($this->relations["last"])) {
 104                         return $this->relations["last"];
 105                 }
 106                 return null;
 107         }
 108
 109         /**
 110          * Get the URL of the link's "first" relation
 111          *
 112          * @return \http\Url
 113          */
 114         function getFirst() {
 115                 if (isset($this->relations["first"])) {
 116                         return $this->relations["first"];
 117                 }
 118                 return null;
 119         }
 120
 121         /**
 122          * Get the page sequence of the current link's relation
 123          *
 124          * @param string $which The relation of which to extract the page
 125          * @return int The current page sequence
 126          */
 127         function getPage($which) {
 128                 if (($link = $this->{"get$which"}())) {
 129                         $url = new Url($link, null, 0);
 130                         $qry = new QueryString($url->query);
 131                         return $qry->getInt("page", 1);
 132                 }
 133                 return 1;
 134         }
 135 }