BookStack Code Mirror - bookstack/blob - app/References/CrossLinkParser.php

1 <?php

3 namespace BookStack\References;

5 use BookStack\Model;

6 use BookStack\References\ModelResolvers\BookLinkModelResolver;

7 use BookStack\References\ModelResolvers\BookshelfLinkModelResolver;

8 use BookStack\References\ModelResolvers\ChapterLinkModelResolver;

9 use BookStack\References\ModelResolvers\CrossLinkModelResolver;

10 use BookStack\References\ModelResolvers\PageLinkModelResolver;

11 use BookStack\References\ModelResolvers\PagePermalinkModelResolver;

12 use DOMDocument;

13 use DOMXPath;

15 class CrossLinkParser

16 {

17 /**

18 * @var CrossLinkModelResolver[]

19 */

20 protected array $modelResolvers;

22 public function __construct(array $modelResolvers)

23 {

24 $this->modelResolvers = $modelResolvers;

25 }

27 /**

28 * Extract any found models within the given HTML content.

29 *

30 * @return Model[]

31 */

32 public function extractLinkedModels(string $html): array

33 {

34 $models = [];

36 $links = $this->getLinksFromContent($html);

38 foreach ($links as $link) {

39 $model = $this->linkToModel($link);

40 if (!is_null($model)) {

41 $models[get_class($model) . ':' . $model->id] = $model;

42 }

43 }

45 return array_values($models);

46 }

48 /**

49 * Get a list of href values from the given document.

50 *

51 * @returns string[]

52 */

53 protected function getLinksFromContent(string $html): array

54 {

55 $links = [];

57 $html = '<?xml encoding="utf-8" ?><body>' . $html . '</body>';

58 libxml_use_internal_errors(true);

59 $doc = new DOMDocument();

60 $doc->loadHTML($html);

62 $xPath = new DOMXPath($doc);

63 $anchors = $xPath->query('//a[@href]');

65 /** @var \DOMElement $anchor */

66 foreach ($anchors as $anchor) {

67 $links[] = $anchor->getAttribute('href');

68 }

70 return $links;

71 }

73 /**

74 * Attempt to resolve the given link to a model using the instance model resolvers.

75 */

76 protected function linkToModel(string $link): ?Model

77 {

78 foreach ($this->modelResolvers as $resolver) {

79 $model = $resolver->resolve($link);

80 if (!is_null($model)) {

81 return $model;

82 }

83 }

85 return null;

86 }

88 /**

89 * Create a new instance with a pre-defined set of model resolvers, specifically for the

90 * default set of entities within BookStack.

91 */

92 public static function createWithEntityResolvers(): self

93 {

94 return new self([

95 new PagePermalinkModelResolver(),

96 new PageLinkModelResolver(),

97 new ChapterLinkModelResolver(),

98 new BookLinkModelResolver(),

99 new BookshelfLinkModelResolver(),

100 ]);

101 }

102 }