Question

这是我的代码，我想找出这张图片的网址。它是一个生成随机图像的网站，所以我想总是从这个xPath中抓取图像

xPath = /html/body/section[3]/div/article/div/div[2]/div/div[2]/div/div/a/img

这是我的代码：

$url    = "http://www.funcloud.com/random";
$result = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($url))->xpath("//html/body/section[3]/div/article/div/div[2]/div/div[2]/div/div/a/img@src"));

if($result == null)
 echo 'result is null';

一些想法？

Answer 1

以下是调试方法：

<?php
$url    = "http://www.funcloud.com/random";
$parts = array(
    'body',
    'section[3]',
    'div',
    'article',
    'div',
    'div[2]',
    'div',
    'div[2]',
    'div',
    'div',
    'a',
    'img',
);
$document = simplexml_import_dom(DOMDocument::loadHTML($url));
$xpath = '//html';
$previous_result = array();
foreach($parts as $part)
{
    $xpath .= '/' . $part;
    $result = $document->xpath($xpath);
    if( ! count($result) )
    {
        echo('No content for: ' . $xpath . PHP_EOL);
        break;
    }
    $previous_result = $result;
}

echo('Last good result: ' . PHP_EOL);
var_dump($previous_result);

这给了我：

No content for: //html/body/section[3]
Last good result: 
array(1) {
  [0] =>
  class SimpleXMLElement#1 (1) {
    public $p =>
    string(30) "http://www.funcloud.com/random"
  }
}

看起来你需要调整你的xpath。

修改：实际上看起来服务已经停止：

% curl -D /dev/stdout -o /dev/null -s http://www.funcloud.com/random HTTP/1.1 301 Moved Permanently Server: nginx/1.2.1 Date: Mon, 11 Aug 2014 10:04:55 GMT Content-Type: text/html; charset=UTF-8 Transfer-Encoding: chunked Connection: keep-alive X-Powered-By: PHP/5.4.4-14+deb7u12 Set-Cookie: PHPSESSID=1t636677vk8uor7d6vfo3n4c91; path=/; domain=.funcloud.com Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Location: http://funcloud.com/

PHP Xpath结果始终为null

1 个答案: