1 | <?php |
||
17 | abstract class AbstractCrawler |
||
18 | { |
||
19 | const URL_PREFIX = 'http://last.fm'; |
||
20 | |||
21 | /** |
||
22 | * @var ConnectionInterface |
||
23 | */ |
||
24 | protected $connection; |
||
25 | |||
26 | /** |
||
27 | * AbstractService constructor. |
||
28 | * |
||
29 | * @param ConnectionInterface $connection |
||
30 | */ |
||
31 | public function __construct(ConnectionInterface $connection) |
||
35 | |||
36 | /** |
||
37 | * Crawles a url. |
||
38 | * |
||
39 | * @param string $url |
||
40 | * |
||
41 | * @return Crawler |
||
42 | */ |
||
43 | final protected function crawl($url) |
||
49 | |||
50 | /** |
||
51 | * Parses a url node. |
||
52 | * |
||
53 | * @param Crawler $node |
||
54 | * @param string $attr |
||
55 | * |
||
56 | * @return null|string |
||
57 | */ |
||
58 | final protected function parseUrl(Crawler $node, $attr = 'href') |
||
70 | |||
71 | /** |
||
72 | * Parses an image node. |
||
73 | * |
||
74 | * @param Crawler $node |
||
75 | * |
||
76 | * @return null|string |
||
77 | */ |
||
78 | final protected function parseImage(Crawler $node) |
||
82 | |||
83 | /** |
||
84 | * Parses a string node. |
||
85 | * |
||
86 | * @param Crawler $node |
||
87 | * |
||
88 | * @param bool $multiline |
||
89 | * |
||
90 | * @return null|string |
||
91 | */ |
||
92 | final protected function parseString(Crawler $node, $multiline = false) |
||
110 | |||
111 | /** |
||
112 | * Parses a date note. |
||
113 | * |
||
114 | * @param Crawler $node |
||
115 | * |
||
116 | * @return \DateTime|null |
||
117 | */ |
||
118 | final protected function parseDate(Crawler $node) |
||
128 | } |
||
129 |
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
string
values, the empty string''
is a special case, in particular the following results might be unexpected: