[DomCrawler] Add support for XPath expression evaluation #19430
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| $prefixes = $this->findNamespacePrefixes($xpath); | ||
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| foreach ($this->nodes as $node) { | ||
| $domxpath = $this->createDOMXPath($node->ownerDocument, $prefixes); |
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you can use a single DOMXPath now. As of Symfony 3, it is impossible to have nodes belonging to different documents. They will all belong to $this->document (which can only be null for an empty root crawler, i.e. a crawler not yet initialized)
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| { | ||
| $data = array(); | ||
| $prefixes = $this->findNamespacePrefixes($xpath); | ||
| $domxpath = $this->createDOMXPath($this->document, $prefixes); |
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I would throw a LogicException before that in case $this->document is null, saying you cannot evaluate an expression on an uninitialized crawler.
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| * | ||
| * @param string $xpath An XPath expression | ||
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| * @return array|Crawler An array of evaluation results or a new Crawler instance |
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returning an array of a Crawler makes it difficult to work with this method in a fluent interface. This would be the first method returning a Crawler or something else.
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Yeah, I thought twice before defining the return type. I also don't like it but the DOMXPath::evaluate() returns a simple type value or DOMNodeList. The result depends on the type of xpath query. I figured that the end user knows what it's gonna be since he wrote the query.
Not sure how we could solve it differently (other than defining two methods and verifying results, or forbidding one type of queries).
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+1 👍 |
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Thank you @jakzal. |
…on (jakzal) This PR was merged into the 3.2-dev branch. Discussion ---------- [DomCrawler] Add support for XPath expression evaluation | Q | A | ------------- | --- | Branch? | master | Bug fix? | no | New feature? | yes | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | #19162 | License | MIT | Doc PR | TODO Example usage: ```php <?php use Symfony\Component\DomCrawler\Crawler; use Symfony\Component\VarDumper\VarDumper; require_once __DIR__.'/vendor/autoload.php'; $html = '<html> <body> <span id="article-100" class="article">Article 1</span> <span id="article-101" class="article">Article 2</span> <span id="article-102" class="article">Article 3</span> </body> </html>'; $crawler = new Crawler(); $crawler->addHtmlContent($html); VarDumper::dump($crawler->filterXPath('//span[contains(@id, "article-")]')->evaluate('substring-after(@id, "-")')); // array:3 [ // 0 => "100" // 1 => "101" // 2 => "102" // ] VarDumper::dump($crawler->evaluate('substring-after(//span[contains(@id, "article-")]/@id, "-")')); // array:1 [ // 0 => "100" // ] VarDumper::dump($crawler->filterXPath('//span[@Class="article"]')->evaluate('count(@id)')); // array:3 [ // 0 => 1.0 // 1 => 1.0 // 2 => 1.0 // ] VarDumper::dump($crawler->evaluate('count(//span[@Class="article"])')); // array:1 [ // 0 => 3.0 // ] VarDumper::dump($crawler->evaluate('//span[1]')); // Symfony\Component\DomCrawler\Crawler { } ``` Commits ------- 3148fad [DomCrawler] Add support for XPath expression evaluation
This PR was merged into the master branch. Discussion ---------- [DomCrawler] Document XPath expression evaluation Documents symfony/symfony#19430 Commits ------- 156b047 [DomCrawler] Document XPath expression evaluation
Example usage: