无法使用 Symfony Dom Crawler 获取元素的值

Question

我正在使用 guzzle POST 方法获取 URL。它正在工作并返回我想要的页面。但问题是，当我想获取该页面中表单中的输入元素的值时，爬虫什么也不返回。我不知道为什么。

PHP：

<?php
use Symfony\Component\DomCrawler\Crawler;
use Guzzle\Http\Client;

$client = new Client();

$request = $client->get("https://example.com");
$response = $request->send();
$getRequest = $response->getBody();
$cookie = $response->getHeader("Set-Cookie");


$request = $client->post('https://example.com/page_example.php', array(
    'Content-Type' => 'application/x-www-form-urlencoded',
    'Cookie' => $cookie
    ), array(
        'param1' => 5,
        'param2' => 10,
        'param3' => 20
    ));

$response = $request->send();
$pageHTML = $response->getBody();

//fetch orderID
$crawler = new Crawler($pageHTML);
$orderID = $crawler->filter("input[name=orderId]")->attr('value');//there is only one element with this name

echo $orderID; //returns nothing

我应该怎么办 ？

Answer 1

您不必创建爬网程序：

$crawler = $client->post('https://example.com/page_example.php', array(
'Content-Type' => 'application/x-www-form-urlencoded',
'Cookie' => $cookie
), array(
    'param1' => 5,
    'param2' => 10,
    'param3' => 20
)); 
$orderID = $crawler->filter("input[name=orderId]")->attr('value');

这假设您的 POST 没有被重定向，如果被重定向，您应该在调用过滤器函数之前添加：

$this->assertTrue($client->getResponse()->isRedirect());
$crawler = $client->followRedirect();