grade.php

<?php
require_once('lti.php');

if (empty($_SESSION['authenticated'])) {
    echo 'Error: You do not have permission to visit this page.';
    die();
}

// Only return mark is scoring is enabled
if (!empty($_SESSION['config']['lis_outcome_service_url'])) {
    // Give participation mark
    $student_grade = 1;

    $outcome_url = $_SESSION['config']['lis_outcome_service_url'];
    $consumer_key = $_SESSION['config']['oauth_consumer_key'];
    $key_secret = json_decode($config->key_secret, true);
    $consumer_secret = $key_secret[$consumer_key];

    $hmac_method = new OAuthSignatureMethod_HMAC_SHA1();

    $body = '<?xml version = "1.0" encoding = "UTF-8"?>
		<imsx_POXEnvelopeRequest xmlns = "http://www.imsglobal.org/services/ltiv1p1/xsd/imsoms_v1p0">
			<imsx_POXHeader>
				<imsx_POXRequestHeaderInfo>
					<imsx_version>V1.0</imsx_version>
					<imsx_messageIdentifier>' . $_SERVER['REQUEST_TIME'] . '</imsx_messageIdentifier>
				</imsx_POXRequestHeaderInfo>
			</imsx_POXHeader>
			<imsx_POXBody>
				<replaceResultRequest>
					<resultRecord>
						<sourcedGUID>
							<sourcedId>' . $_SESSION['config']['lis_result_sourcedid'] . '</sourcedId>
						</sourcedGUID>
						<result>
							<resultScore>
								<language>en</language>
								<textString>' . $student_grade . '</textString>
							</resultScore>
						</result>
					</resultRecord>
				</replaceResultRequest>
			</imsx_POXBody>
		</imsx_POXEnvelopeRequest>';

    $hash = base64_encode(sha1($body, TRUE));
    $params = array('oauth_body_hash' => $hash);
    $token = '';
    $content_type = 'application/xml';

    $hmac_method = new OAuthSignatureMethod_HMAC_SHA1();
    $consumer = new OAuthConsumer($consumer_key, $consumer_secret);
    $outcome_request = OAuthRequest::from_consumer_and_token($consumer, $token, 'POST', $outcome_url, $params);
    $outcome_request->sign_request($hmac_method, $consumer, $token);

    $header = $outcome_request->to_header();
    $header = $header . "\r\nContent-type: " . $content_type . "\r\n";
    $options = array(
        'http' => array(
            'method' => 'POST',
            'content' => $body,
            'header' => $header,
        ),
    );

    $ctx = stream_context_create($options);
    $fp = @fopen($outcome_url, 'rb', FALSE, $ctx);
    $response = @stream_get_contents($fp);
}
?>