PHP $xpath->query expression not working

问题

PHP xpath query not working. any idea?

Problem # 1
HTML Source:

<tr>
    <td class="abc pqr xyz">Some contents i want to capture</td>
</tr>
<tr>
    <td class="abc pqr xyz">more content i want to capture too</td>
</tr>
<tr>
    <td class="abc pqr xyz">all row in this table i want to capture</td>
</tr>
<tr>
    <td class="abc pqr xyz">they are all pokemon, i want to capture</td>
</tr>

PHP i tried:

$url = "http://www.example.com/";

$opts = array('http'=>array('header' => "User-Agent:MyAgent/1.0\r\n"));
$context = stream_context_create($opts);
$text = file_get_contents($url,false,$context);

$dom = new DOMDocument();
@$dom->loadHTML($text);
$xpath = new DOMXPath($dom);

$divs = $xpath->query('//div/@class="abc pqr xyz"/');
foreach($divs as $b){
    //echo $b->name.'<br />';
    print_r($b);
}

But nothing came, any help for the right expression for this query?

Problem # 2
i wanted to check if i am getting content, so i tried this and got all href links:

$divs = $xpath->query('//a/@href');
foreach($divs as $b){
    print_r($b); // this is line #19
}

I got this error:

DOMAttr Object
Warning: print_r(): Not yet implemented in C:\xampp\htdocs\testing\index.php on line 19

any idea, why i am getting this warning?

Problem # 3

                    <td colspan="2" style="">
                        <h3><a href="http://www.example.com/?id=xx" title="View more">I am not sure about the title</a>

                                <small class="comeoneman andwomen">Not a shoe</span>

                        </h3>

                        <div class="blahblah">This is just blah blah blah</div>                     

                    </td>
                    <td colspan="2" style="">
                        <h3><a href="http://www.example.com/?id=xx" title="View more">I am not sure about the title</a>

                                <small class="comeoneman andwomen">No a shoe</span>

                        </h3>

                        <div class="blahblah">This is just blah blah blah</div>                     

                    </td>

any idea how can i get this info and convert it to array like this:

array (
  title => I am not sure about the title,
  link => http://www.example.com/?id=xx,
  small => not a shoe,
  blahblah => This is just blah blah blah
)

回答1:

Problem #1

Based on your markup, you're trying to target <td> tags, but in your query, it's //div, which doesn't make sense. Target <td>'s:

$rows = $xpath->query('//tr/td[@class = "abc pqr xyz"]');
foreach($rows as $b){
    echo $b->nodeValue . '<br/>';
}

Sample Output

Problem #2

This is most likely related to this issue:

https://bugs.php.net/bug.php?id=61858&edit=1

Problem #3

You could just continue to use xpath to target the desired values. Select all those <td>'s and from there, just use each of them as the context node:

$data = array();
$td = $xpath->query('//td');
foreach($td as $b){
    $data[] = array(
        'title' => $xpath->evaluate('string(./h3/a)', $b),
        'link' => $xpath->evaluate('string(./h3/a/@href)', $b),
        'small' => trim($xpath->evaluate('string(./h3/small)', $b)),
        'blahblah' => trim($xpath->evaluate('string(./div[@class="blahblah"])', $b)),
    );
}

Sample Output

来源：https://stackoverflow.com/questions/28080875/php-xpath-query-expression-not-working

标签

php

html

xpath

domdocument