or tag). This will * be the context nodes for all of the following expressions. This expression usually * starts with a single forward slash. * * Use {@see XPathAbstract::getExpressionItem()} to read this parameter */ const XPATH_EXPRESSION_ITEM = ''; /** * XPath expression for extracting an item title from the item context * This expression should match a node contained within each article item node * containing the article headline. It should start with a dot followed by two * forward slashes, referring to any descendant nodes of the article item node. * * Use {@see XPathAbstract::getExpressionItemTitle()} to read this parameter */ const XPATH_EXPRESSION_ITEM_TITLE = ''; /** * XPath expression for extracting an item's content from the item context * This expression should match a node contained within each article item node * containing the article content or description. It should start with a dot * followed by two forward slashes, referring to any descendant nodes of the * article item node. * * Use {@see XPathAbstract::getExpressionItemContent()} to read this parameter */ const XPATH_EXPRESSION_ITEM_CONTENT = ''; /** * XPath expression for extracting an item link from the item context * This expression should match a node's attribute containing the article URL * (usually the href attribute of an tag). It should start with a dot * followed by two forward slashes, referring to any descendant nodes of * the article item node. Attributes can be selected by prepending an @ char * before the attributes name. * * Use {@see XPathAbstract::getExpressionItemUri()} to read this parameter */ const XPATH_EXPRESSION_ITEM_URI = ''; /** * XPath expression for extracting an item author from the item context * This expression should match a node contained within each article item * node containing the article author's name. It should start with a dot * followed by two forward slashes, referring to any descendant nodes of * the article item node. * * Use {@see XPathAbstract::getExpressionItemAuthor()} to read this parameter */ const XPATH_EXPRESSION_ITEM_AUTHOR = ''; /** * XPath expression for extracting an item timestamp from the item context * This expression should match a node or node's attribute containing the * article timestamp or date (parsable by PHP's strtotime function). It * should start with a dot followed by two forward slashes, referring to * any descendant nodes of the article item node. Attributes can be * selected by prepending an @ char before the attributes name. * * Use {@see XPathAbstract::getExpressionItemTimestamp()} to read this parameter */ const XPATH_EXPRESSION_ITEM_TIMESTAMP = ''; /** * XPath expression for extracting item enclosures (media content like * images or movies) from the item context * This expression should match a node's attribute containing an article * image URL (usually the src attribute of an tag or a style * attribute). It should start with a dot followed by two forward slashes, * referring to any descendant nodes of the article item node. Attributes * can be selected by prepending an @ char before the attributes name. * * Use {@see XPathAbstract::getExpressionItemEnclosures()} to read this parameter */ const XPATH_EXPRESSION_ITEM_ENCLOSURES = ''; /** * XPath expression for extracting an item category from the item context * This expression should match a node or node's attribute contained * within each article item node containing the article category. This * could be inside
or tags or sometimes be hidden * in a data attribute. It should start with a dot followed by two * forward slashes, referring to any descendant nodes of the article * item node. Attributes can be selected by prepending an @ char * before the attributes name. * * Use {@see XPathAbstract::getExpressionItemCategories()} to read this parameter */ const XPATH_EXPRESSION_ITEM_CATEGORIES = ''; /** * Fix encoding * Set this to true for fixing feed encoding by invoking PHP's utf8_decode * function on all extracted texts. Try this in case you see "broken" or * "weird" characters in your feed where you'd normally expect umlauts * or any other non-ascii characters. * * Use {@see XPathAbstract::getSettingFixEncoding()} to read this parameter */ const SETTING_FIX_ENCODING = false; /** * Internal storage for resulting feed name, automatically detected * @var string */ private $feedName; /** * Internal storage for resulting feed name, automatically detected * @var string */ private $feedUri; /** * Internal storage for resulting feed favicon, automatically detected * @var string */ private $feedIcon; public function getName() { return $this->feedName ?: parent::getName(); } public function getURI() { return $this->feedUri ?: parent::getURI(); } public function getIcon() { return $this->feedIcon ?: parent::getIcon(); } /** * Source Web page URL (should provide either HTML or XML content) * @return string */ protected function getSourceUrl() { return static::FEED_SOURCE_URL; } /** * XPath expression for extracting the feed title from the source page * @return string */ protected function getExpressionTitle() { return static::XPATH_EXPRESSION_FEED_TITLE; } /** * XPath expression for extracting the feed favicon from the source page * @return string */ protected function getExpressionIcon() { return static::XPATH_EXPRESSION_FEED_ICON; } /** * XPath expression for extracting the feed items from the source page * @return string */ protected function getExpressionItem() { return static::XPATH_EXPRESSION_ITEM; } /** * XPath expression for extracting an item title from the item context * @return string */ protected function getExpressionItemTitle() { return static::XPATH_EXPRESSION_ITEM_TITLE; } /** * XPath expression for extracting an item's content from the item context * @return string */ protected function getExpressionItemContent() { return static::XPATH_EXPRESSION_ITEM_CONTENT; } /** * XPath expression for extracting an item link from the item context * @return string */ protected function getExpressionItemUri() { return static::XPATH_EXPRESSION_ITEM_URI; } /** * XPath expression for extracting an item author from the item context * @return string */ protected function getExpressionItemAuthor() { return static::XPATH_EXPRESSION_ITEM_AUTHOR; } /** * XPath expression for extracting an item timestamp from the item context * @return string */ protected function getExpressionItemTimestamp() { return static::XPATH_EXPRESSION_ITEM_TIMESTAMP; } /** * XPath expression for extracting item enclosures (media content like * images or movies) from the item context * @return string */ protected function getExpressionItemEnclosures() { return static::XPATH_EXPRESSION_ITEM_ENCLOSURES; } /** * XPath expression for extracting an item category from the item context * @return string */ protected function getExpressionItemCategories() { return static::XPATH_EXPRESSION_ITEM_CATEGORIES; } /** * Fix encoding * @return string */ protected function getSettingFixEncoding() { return static::SETTING_FIX_ENCODING; } /** * Internal helper method for quickly accessing all the user defined constants * in derived classes * * @param $name * @return bool|string */ private function getParam($name) { switch ($name) { case 'url': return $this->getSourceUrl(); case 'feed_title': return $this->getExpressionTitle(); case 'feed_icon': return $this->getExpressionIcon(); case 'item': return $this->getExpressionItem(); case 'title': return $this->getExpressionItemTitle(); case 'content': return $this->getExpressionItemContent(); case 'uri': return $this->getExpressionItemUri(); case 'author': return $this->getExpressionItemAuthor(); case 'timestamp': return $this->getExpressionItemTimestamp(); case 'enclosures': return $this->getExpressionItemEnclosures(); case 'categories': return $this->getExpressionItemCategories(); case 'fix_encoding': return $this->getSettingFixEncoding(); } } /** * Should provide the source website HTML content * can be easily overwritten for example if special headers or auth infos are required * @return string */ protected function provideWebsiteContent() { return getContents($this->feedUri); } /** * Should provide the feeds title * * @param \DOMXPath $xpath * @return string */ protected function provideFeedTitle(\DOMXPath $xpath) { $title = $xpath->query($this->getParam('feed_title')); if (count($title) === 1) { return $this->fixEncoding($this->getItemValueOrNodeValue($title)); } } /** * Should provide the URL of the feed's favicon * * @param \DOMXPath $xpath * @return string */ protected function provideFeedIcon(\DOMXPath $xpath) { $icon = $xpath->query($this->getParam('feed_icon')); if (count($icon) === 1) { return $this->cleanMediaUrl($this->getItemValueOrNodeValue($icon)); } } /** * Should provide the feed's items. * * @param \DOMXPath $xpath * @return \DOMNodeList */ protected function provideFeedItems(\DOMXPath $xpath) { return @$xpath->query($this->getParam('item')); } public function collectData() { $this->feedUri = $this->getParam('url'); $webPageHtml = new \DOMDocument(); libxml_use_internal_errors(true); $webPageHtml->loadHTML($this->provideWebsiteContent()); libxml_clear_errors(); libxml_use_internal_errors(false); $xpath = new \DOMXPath($webPageHtml); $this->feedName = $this->provideFeedTitle($xpath); $this->feedIcon = $this->provideFeedIcon($xpath); $entries = $this->provideFeedItems($xpath); if ($entries === false) { return; } foreach ($entries as $entry) { $item = new FeedItem(); foreach (['title', 'content', 'uri', 'author', 'timestamp', 'enclosures', 'categories'] as $param) { $expression = $this->getParam($param); if ('' === $expression) { continue; } //can be a string or DOMNodeList, depending on the expression result $typedResult = @$xpath->evaluate($expression, $entry); if ( $typedResult === false || ($typedResult instanceof \DOMNodeList && count($typedResult) === 0) || (is_string($typedResult) && strlen(trim($typedResult)) === 0) ) { continue; } $value = $this->getItemValueOrNodeValue($typedResult, $param === 'content'); $item->__set($param, $this->formatParamValue($param, $value)); } $itemId = $this->generateItemId($item); if (null !== $itemId) { $item->setUid($itemId); } $this->items[] = $item; } } /** * @param $param * @param $value * @return string|array */ protected function formatParamValue($param, $value) { $value = $this->fixEncoding($value); switch ($param) { case 'title': return $this->formatItemTitle($value); case 'content': return $this->formatItemContent($value); case 'uri': return $this->formatItemUri($value); case 'author': return $this->formatItemAuthor($value); case 'timestamp': return $this->formatItemTimestamp($value); case 'enclosures': return $this->formatItemEnclosures($value); case 'categories': return $this->formatItemCategories($value); } return $value; } /** * Formats the title of a feed item. Takes extracted raw title and returns it formatted * as string. * Can be easily overwritten for in case the value needs to be transformed into something * else. * @param string $value * @return string */ protected function formatItemTitle($value) { return $value; } /** * Formats the timestamp of a feed item. Takes extracted raw timestamp and returns unix * timestamp as integer. * Can be easily overwritten for example if a special format has to be expected on the * source website. * @param string $value * @return string */ protected function formatItemContent($value) { return $value; } /** * Formats the URI of a feed item. Takes extracted raw URI and returns it formatted * as string. * Can be easily overwritten for in case the value needs to be transformed into something * else. * @param string $value * @return string */ protected function formatItemUri($value) { if (strlen($value) === 0) { return ''; } if (strpos($value, 'http://') === 0 || strpos($value, 'https://') === 0) { return $value; } return urljoin($this->feedUri, $value); } /** * Formats the author of a feed item. Takes extracted raw author and returns it formatted * as string. * Can be easily overwritten for in case the value needs to be transformed into something * else. * @param string $value * @return string */ protected function formatItemAuthor($value) { return $value; } /** * Formats the timestamp of a feed item. Takes extracted raw timestamp and returns unix * timestamp as integer. * Can be easily overwritten for example if a special format has to be expected on the * source website. * @param string $value * @return false|int */ protected function formatItemTimestamp($value) { return strtotime($value); } /** * Formats the enclosures of a feed item. Takes extracted raw enclosures and returns them * formatted as array. * Can be easily overwritten for in case the values need to be transformed into something * else. * @param string $value * @return array */ protected function formatItemEnclosures($value) { return [$this->cleanMediaUrl($value)]; } /** * Formats the categories of a feed item. Takes extracted raw categories and returns them * formatted as array. * Can be easily overwritten for in case the values need to be transformed into something * else. * @param string $value * @return array */ protected function formatItemCategories($value) { return [$value]; } /** * @param $mediaUrl * @return string|void */ protected function cleanMediaUrl($mediaUrl) { $pattern = '~(?:http(?:s)?:)?[\/a-zA-Z0-9\-=_,\.\%]+\.(?:jpg|gif|png|jpeg|ico|mp3|webp){1}~i'; $result = preg_match($pattern, $mediaUrl, $matches); if (1 !== $result) { return; } return urljoin($this->feedUri, $matches[0]); } /** * @param $typedResult * @return string */ protected function getItemValueOrNodeValue($typedResult, $returnXML = false) { if ($typedResult instanceof \DOMNodeList) { $item = $typedResult->item(0); if ($item instanceof \DOMElement) { // Don't escape XML if ($returnXML) { return ($item->ownerDocument ?? $item)->saveXML($item); } $text = $item->nodeValue; } elseif ($item instanceof \DOMAttr) { $text = $item->value; } elseif ($item instanceof \DOMText) { $text = $item->wholeText; } } elseif (is_string($typedResult) && strlen($typedResult) > 0) { $text = $typedResult; } else { throw new \Exception('Unknown type of XPath expression result.'); } $text = trim($text); if ($returnXML) { return htmlspecialchars($text); } return $text; } /** * Fixes feed encoding by invoking PHP's utf8_decode function on extracted texts. * Useful in case of "broken" or "weird" characters in the feed where you'd normally * expect umlauts. * * @param $input * @return string */ protected function fixEncoding($input) { return $this->getParam('fix_encoding') ? utf8_decode($input) : $input; } /** * Allows overriding default mechanism determining items Uid's * * @param FeedItem $item * @return string|null */ protected function generateItemId(FeedItem $item) { return null; } }