/**
* Make an OAI-PMH request. Die if there is an error; return a SimpleXML object
* on success.
*
* @param string $verb OAI-PMH verb to execute.
* @param array $params GET parameters for ListRecords method.
*
* @return object SimpleXML-formatted response.
*/
protected function sendRequest($verb, $params = array())
{
// Debug:
if ($this->verbose) {
Console::write("Sending request: verb = {$verb}, params = " . print_r($params, true));
}
// Set up retry loop:
while (true) {
// Set up the request:
$request = new Client(null, array('timeout' => 60));
$request->setUri($this->baseURL);
// Load request parameters:
$query = $request->getRequest()->getQuery();
$query->set('verb', $verb);
foreach ($params as $key => $value) {
$query->set($key, $value);
}
// Perform request and die on error:
$result = $request->setMethod('GET')->send();
if ($result->getStatusCode() == 503) {
$delayHeader = $result->getHeaders()->get('Retry-After');
$delay = is_object($delayHeader) ? $delayHeader->getDeltaSeconds() : 0;
if ($delay > 0) {
if ($this->verbose) {
Console::writeLine("Received 503 response; waiting {$delay} seconds...");
}
sleep($delay);
}
} else {
if (!$result->isSuccess()) {
throw new \Exception('HTTP Error');
} else {
// If we didn't get an error, we can leave the retry loop:
break;
}
}
}
// If we got this far, there was no error -- send back response.
return $this->processResponse($result->getBody());
}
