PHP Consuming RESTful APIs Fetching a URL with Arbitrary Headers

PHP Consuming RESTful APIs

Fetching a URL with Arbitrary Headers

Problem

You want to retrieve a URL that requires specific headers to be sent with the request for the page.

Solution

Set the header stream context option when using the http stream. The header value must be a single string. Separate multiple headers with a carriage return and newline (\r\n inside a double-quoted string). For example:

       $url = 'http://www.example.com/special-header.php';

       $header = "X-Factor: 12\r\nMy-Header: Bob";

       $options = array('header' => $header);

       // Create the stream context

       $context = stream_context_create(array('http' => $options));

       // Pass the context to file_get_contents()

       print file_get_contents($url, false, $context);

With cURL, set the CURLOPT_HTTPHEADER option to an array of headers to send:

       $c = curl_init('http://www.example.com/special-header.php');

       curl_setopt($c, CURLOPT_RETURNTRANSFER, true);

       curl_setopt($c, CURLOPT_HTTPHEADER, array('X-Factor: 12', 'My-Header: Bob'));

       $page = curl_exec($c);

       curl_close($c);

With HTTP_Request2, use the setHeader() method, as shown:

       require 'HTTP/Request2.php';

       $r = new HTTP_Request2('http://www.example.com/special-header.php');

       $r->setHeader(array('X-Factor' => 12, 'My-Header','Bob'));

       $page = $r->send()->getBody();

       print $page;

Discussion

cURL has special options for setting the Referer and User-Agent request headers CURLOPT_REFERER and CURLOPT_USERAGENT. Here’s how you use each of these options:

       $c = curl_init('http://www.example.com/submit.php');

       curl_setopt($c, CURLOPT_RETURNTRANSFER, true);

       curl_setopt($c, CURLOPT_REFERER, 'http://www.example.com/form.php');

       curl_setopt($c, CURLOPT_USERAGENT, 'cURL via PHP');

       $page = curl_exec($c);

       curl_close($c);