Question

我正在尝试将DOM解析器用于多个链接，然后比较2对值。有人可以帮助我解决我的错误吗？我不可能对@class="badge-item-img"进行比较吗？编辑我应该提到第一个foreach有效但是当试图找到第二个foreach时没有显示结果。

<?php
// Init the '$url_array' array.
$url_array = array();
$url_array[] = 'http://www.reddit.com/r/funny';
$url_array[] = 'http://www.9gag.com/';

// Init the return '$ret' array.
$ret = array();

// Roll through the '$url_array' array.
foreach ($url_array as $url_value) {
  $html = file_get_contents($url_value);
  $dom = new DOMDocument();
  $dom2 = new DOMDocument();
  @$dom->loadHTML($html);

  $xpath = new DOMXPath($dom);
  $xpath2 = new DOMXPath($dom2);
  $hyperlinks = $xpath->evaluate('//a[@class="thumbnail "]');
  $hyperlinks2 = $xpath2->evaluate('//a[@class="badge-item-img"]');

  foreach($hyperlinks as $hyperlink) {
    if(strpos($hyperlink->getAttribute('href'), 'http://i.imgur.com/') !== FALSE){
      $ret[] = "<img style='padding-left:30%' width=\"500\" src=\"" . $hyperlink->getAttribute('href') . "\" alt=\"\" />"
             . "<br>"
             . "<br>"
             . "<br>"
             ;

    }
    foreach($hyperlinks2 as $hyperlinker) {
            $ret[] = "<img style='padding-left:30%' width=\"500\" src=\"" . $hyperlinker->getAttribute('href') . "\" alt=\"\" />"
             . "<br>"
             . "<br>"
             . "<br>"
             ;
    }
  } 
  }
// Roll through the '$ret' array.
foreach($ret as $ret_value) {
  echo $ret_value;

Answer 1

您发送的代码似乎缺少以下一行：

@$dom2->loadHTML($html);

...我不确定xPath搜索，但如果单个实体的HTML中有多个类，则可能也会遇到问题。是的是有效的XHTML。

我还建议您将URL存储在第一个循环中，并在演示循环中添加演示文稿信息。

foreach($ret as $ret_value) {
  echo '<img style="padding-left:30%" width="500" src="' . $ret_value . '"  alt="" /><br /><br /><br />';
}

Answer 2

我修复了这个错误，现在你可以从9gag

中提取图片了

<?php
// Init the '$url_array' array.
$url_array = array();
$url_array['http://www.reddit.com/r/funny'] = array( 'href', '//a[@class="thumbnail "]', 'http://i.imgur.com/');
$url_array['http://www.9gag.com/'] = array( 'src', '//img[@class="badge-item-img"]' );

// Init the return '$ret' array.
$ret = array();

// Roll through the '$url_array' array.
foreach ($url_array as $url_value => $ary_rules) {
  $html = file_get_contents($url_value);
  $dom = new DOMDocument();
  libxml_use_internal_errors(true);
  $dom->loadHTML($html);
  libxml_clear_errors();

  $xpath = new DOMXPath($dom);
  $hyperlinks = $xpath->evaluate($ary_rules[1]);

  foreach($hyperlinks as $hyperlink) {
    if( !$ary_rules[2] || strpos($hyperlink->getAttribute($ary_rules[0]), $ary_rules[2] ) !== FALSE){
      $ret[$url_value][] = $hyperlink->getAttribute($ary_rules[0]);
    }
  }
}
// Roll through the '$ret' array.
foreach($ret as $ret_value_list) {
    foreach($ret_value_list as $ret_value){ 
        echo "<img style='padding-left:30%' width=\"500\" src=\"" . $ret_value . "\" alt=\"\" />"
             . "<br>"
             . "<br>"
             . "<br>"
             ;
    }
}

通过PHP DOM解析多个链接以查找类

2 个答案: