Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
726 views
in Technique[技术] by (71.8m points)

html - XPath Query: get attribute href from a tag

I want to use XPath to get the href attribute from an a-tag, but it has two occurrences within the same file. How am I getting along? I need to check IF there is an href attribute with value $street/object, I have got this code and it does not work:

$product_photo     = $xpath->query("//a[contains(@href,'{$object_street}fotos/')][1]");
        $product_360       = $xpath->query("//a[contains(@href,'{$object_street}360-fotos/')][1]");
        $product_blueprint = $xpath->query("//a[contains(@href,'{$object_street}plattegrond/')][1]");
        $product_video     = $xpath->query("//a[contains(@href,'{$object_street}video/')][1]");

It does not return anything at all. Who can help me out?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

For the following HTML document:

<html>
  <body>
    <a href="http://www.example.com">Example</a> 
    <a href="http://www.stackoverflow.com">SO</a> 
  </body>
</html>

The xpath query /html/body//a/@href (or simply //a/@href) will return:

    http://www.example.com
    http://www.stackoverflow.com

To select a specific instance use /html/body//a[N]/@href,

    $ /html/body//a[2]/@href
    http://www.stackoverflow.com

To test for strings contained in the attribute and return the attribute itself place the check on the tag not on the attribute:

    $ /html/body//a[contains(@href,'example')]/@href
    http://www.example.com

Mixing the two:

    $ /html/body//a[contains(@href,'com')][2]/@href
    http://www.stackoverflow.com

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...