How do I send a drupal_http_request() with GET method?

Question

Following examples found here and in API, I tried 2 methods, both return a bad request status message.

First method

$data = 'name=value&name1=value1';

$options = array(
  'method' => 'GET',
  'data' => $data,
  'timeout' => 15,
  'headers' => array('Content-Type' => 'application/x-www-form-urlencoded'),
);

$result = drupal_http_request('http://example.com/foo', $options);

dpm($result);

Second method

$data = array(
  'key1' => $value1,
  'key2' => $value2,
);

$full_url = url('http://example.com/foo', array('query' => $data));

$options = array(
  'method' => 'GET',
  'timeout' => 15,
  'headers' => array('Content-Type' => 'application/x-www-form-urlencoded'),
);
$result = drupal_http_request($full_url, $options);

dpm($result);

Which one is the good one and what's wrong ? Thank you

Edit

This is dpm($result)

Answer 1

The first method is correct; you should not use url() for an external URL that is passed to drupal_http_request(), except (for example) when you want other modules to alter the hook via their hook_url_outbound_alter() implementations, or you want to let url() split off the fragment (or the query) from the URL. (The fragment is used to set $options['fragment'], when it's not already set; the query is added to $options['query'].

The code run by url() for an external URL is the following one. (I showed only the relevant code; where I omitted code, I used an // Omissis comment. I also removed the original comments from the code and added mine to evidence some code parts.)

if (!isset($options['external'])) {
  $options['external'] = $path === $_GET['q'] ? FALSE : url_is_external($path);
}

// Omissis

if ($options['external']) {
  if (strpos($path, '#') !== FALSE) {
    list($path, $old_fragment) = explode('#', $path, 2);
    if (isset($old_fragment) && !$options['fragment']) {
      $options['fragment'] = '#' . $old_fragment;
    }
  }

  if ($options['query']) {
    $path .= (strpos($path, '?') !== FALSE ? '&' : '?') . drupal_http_build_query($options['query']);
  }

  // Change the URL protocol basing on a Drupal local setting.
  if (isset($options['https']) && variable_get('https', FALSE)) {
    if ($options['https'] === TRUE) {
      $path = str_replace('http://', 'https://', $path);
    }
    elseif ($options['https'] === FALSE) {
      $path = str_replace('https://', 'http://', $path);
    }
  }

  return $path . $options['fragment'];
}

Apart from what I reported before, there isn't much any pro in using url() when used for a string you already know it contains an external URL. The part commented with Change the URL protocol basing on a Drupal local setting. only changes the used protocol basing on the value of $options['https'], when a local Drupal settings has been set to TRUE. For a string that contains already an external URL, which is then passed to drupal_http_request(), that code isn't much helpful; you would know already if the external URL needs to be accessed via https:// or http://, and you would not want to change the used protocol basing on a local setting.

application/x-www-form-urlencoded is the content type used when POSTing data, while you are GETting data.

To build the query data, you could also use drupal_http_build_query(), which the same function used from url() for the same purpose.

$data = array('name' => 'value', 'name1' => 'value1');

$options = array(
  'method' => 'GET',
  'data' => drupal_http_build_query($data),
  'timeout' => 15,
);

$result = drupal_http_request('http://example.com/foo', $options);