PHP $ xpath->查询表达式不起作用 [英] PHP $xpath->query expression not working

问题描述

PHP xpath查询不起作用。任何想法？

问题1

HTML来源：

 < tr> 
< td class =abc pqr xyz>我想要捕捉的一些内容< / td> 
< / tr> 
< tr> 
< td class =abc pqr xyz>更多的内容我也想捕捉< / td> 
< / tr> 
< tr> 
< td class =abc pqr xyz>我想捕捉此表格中的所有行< / td> 
< / tr> 
< tr> 
< td class =abc pqr xyz>他们都是口袋妖怪，我想要捕捉< / td> 
< / tr> 
  

PHP我试过了：

  $ url =http://www.example.com/; 
 $ b $ opts = array（'http'=> array（'header'=>User-Agent：MyAgent / 1.0 \r\\\
））; 
 $ 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）; 
} 
  

但是没有任何东西可以帮助您查询正确的表达式？

---

问题2

i通缉检查我是否获得内容，所以我尝试了这一点并获得了所有的href链接：

  $ divs = $ xpath->查询（ '// A / @ HREF'）; 
 foreach（$ divs为$ b）{
 print_r（$ b）; //这是行＃19 
} 
  

我得到这个错误：

  DOMAttr对象
警告：print_r（）：尚未在C：\xampp\htdocs\testing\index中实现.php on line 19 
  

任何想法，为什么我得到这个警告？

---

问题3

 < td colspan =2style => 
< h3>< a href =http://www.example.com/?id=xxtitle =查看更多>我不确定标题&l​​t; / a> 
 
  
< / h3> 
 
< div class =blahblah>这仅仅是等等等等< / div> 
 
< / td> 
< td colspan =2style => 
< h3>< a href =http://www.example.com/?id=xxtitle =查看更多>我不确定标题&l​​t; / a> 
 
< small class =comeoneman andwomen>没有鞋< / span> 
 
< / h3> 
 
< div class =blahblah>这仅仅是等等等等< / div> 
 
< / td> 
  

任何想法如何获取此信息并将其转换为像这样的数组：

 数组（
 title =>我不确定标题，
 link => http：// www .example.com /？id = xx，
 small =>不是鞋子，
 blahblah =>这只是等等等等等等）
  

解决方案

问题＃1

你的标记，你试图定位< td> 标签，但是在你的查询中，它是 // div ，这是没有道理的。 Target < td> '：

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

样本输出

问题2

最有可能与此问题有关：

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

问题3

您可以继续使用xpath来定位所需的值。选择所有< td> 的，然后从这里选择每一个作为上下文节点：

  $ 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）），
）; 
} 
  

样本输出

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
)

解决方案

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

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