/**
  * Test lti_build_request's resource_link_description and ensure
  * that the newlines in the description are correct.
  */
 public function test_lti_build_request_description()
 {
     $this->resetAfterTest();
     self::setUser($this->getDataGenerator()->create_user());
     $course = $this->getDataGenerator()->create_course();
     $instance = $this->getDataGenerator()->create_module('lti', array('intro' => "<p>This</p>\nhas\r\n<p>some</p>\nnew\n\rlines", 'introformat' => FORMAT_HTML, 'course' => $course->id));
     $typeconfig = array('acceptgrades' => 1, 'forcessl' => 0, 'sendname' => 2, 'sendemailaddr' => 2, 'customparameters' => '');
     $params = lti_build_request($instance, $typeconfig, $course, null);
     $ncount = substr_count($params['resource_link_description'], "\n");
     $this->assertGreaterThan(0, $ncount);
     $rcount = substr_count($params['resource_link_description'], "\r");
     $this->assertGreaterThan(0, $rcount);
     $this->assertEquals($ncount, $rcount, 'The number of \\n characters should be the same as the number of \\r characters');
     $rncount = substr_count($params['resource_link_description'], "\r\n");
     $this->assertGreaterThan(0, $rncount);
     $this->assertEquals($ncount, $rncount, 'All newline characters should be a combination of \\r\\n');
 }

/**
 * Return the launch data required for opening the external tool.
 *
 * @param  stdClass $instance the external tool activity settings
 * @return array the endpoint URL and parameters (including the signature)
 * @since  Moodle 3.0
 */
function lti_get_launch_data($instance)
{
    global $PAGE, $CFG;
    if (empty($instance->typeid)) {
        $tool = lti_get_tool_by_url_match($instance->toolurl, $instance->course);
        if ($tool) {
            $typeid = $tool->id;
        } else {
            $typeid = null;
        }
    } else {
        $typeid = $instance->typeid;
        $tool = lti_get_type($typeid);
    }
    if ($typeid) {
        $typeconfig = lti_get_type_config($typeid);
    } else {
        // There is no admin configuration for this tool. Use configuration in the lti instance record plus some defaults.
        $typeconfig = (array) $instance;
        $typeconfig['sendname'] = $instance->instructorchoicesendname;
        $typeconfig['sendemailaddr'] = $instance->instructorchoicesendemailaddr;
        $typeconfig['customparameters'] = $instance->instructorcustomparameters;
        $typeconfig['acceptgrades'] = $instance->instructorchoiceacceptgrades;
        $typeconfig['allowroster'] = $instance->instructorchoiceallowroster;
        $typeconfig['forcessl'] = '0';
    }
    // Default the organizationid if not specified.
    if (empty($typeconfig['organizationid'])) {
        $urlparts = parse_url($CFG->wwwroot);
        $typeconfig['organizationid'] = $urlparts['host'];
    }
    if (isset($tool->toolproxyid)) {
        $toolproxy = lti_get_tool_proxy($tool->toolproxyid);
        $key = $toolproxy->guid;
        $secret = $toolproxy->secret;
    } else {
        $toolproxy = null;
        if (!empty($instance->resourcekey)) {
            $key = $instance->resourcekey;
        } else {
            if (!empty($typeconfig['resourcekey'])) {
                $key = $typeconfig['resourcekey'];
            } else {
                $key = '';
            }
        }
        if (!empty($instance->password)) {
            $secret = $instance->password;
        } else {
            if (!empty($typeconfig['password'])) {
                $secret = $typeconfig['password'];
            } else {
                $secret = '';
            }
        }
    }
    $endpoint = !empty($instance->toolurl) ? $instance->toolurl : $typeconfig['toolurl'];
    $endpoint = trim($endpoint);
    // If the current request is using SSL and a secure tool URL is specified, use it.
    if (lti_request_is_using_ssl() && !empty($instance->securetoolurl)) {
        $endpoint = trim($instance->securetoolurl);
    }
    // If SSL is forced, use the secure tool url if specified. Otherwise, make sure https is on the normal launch URL.
    if (isset($typeconfig['forcessl']) && $typeconfig['forcessl'] == '1') {
        if (!empty($instance->securetoolurl)) {
            $endpoint = trim($instance->securetoolurl);
        }
        $endpoint = lti_ensure_url_is_https($endpoint);
    } else {
        if (!strstr($endpoint, '://')) {
            $endpoint = 'http://' . $endpoint;
        }
    }
    $orgid = $typeconfig['organizationid'];
    $course = $PAGE->course;
    $islti2 = isset($tool->toolproxyid);
    $allparams = lti_build_request($instance, $typeconfig, $course, $typeid, $islti2);
    if ($islti2) {
        $requestparams = lti_build_request_lti2($tool, $allparams);
    } else {
        $requestparams = $allparams;
    }
    $requestparams = array_merge($requestparams, lti_build_standard_request($instance, $orgid, $islti2));
    $customstr = '';
    if (isset($typeconfig['customparameters'])) {
        $customstr = $typeconfig['customparameters'];
    }
    $requestparams = array_merge($requestparams, lti_build_custom_parameters($toolproxy, $tool, $instance, $allparams, $customstr, $instance->instructorcustomparameters, $islti2));
    $launchcontainer = lti_get_launch_container($instance, $typeconfig);
    $returnurlparams = array('course' => $course->id, 'launch_container' => $launchcontainer, 'instanceid' => $instance->id, 'sesskey' => sesskey());
    // Add the return URL. We send the launch container along to help us avoid frames-within-frames when the user returns.
    $url = new \moodle_url('/mod/lti/return.php', $returnurlparams);
    $returnurl = $url->out(false);
//.........这里部分代码省略.........

/**
 * Prints a Basic LTI activity
 *
 * $param int $basicltiid       Basic LTI activity id
 */
function lti_view($instance) {
    global $PAGE, $CFG;

    if (empty($instance->typeid)) {
        $tool = lti_get_tool_by_url_match($instance->toolurl, $instance->course);
        if ($tool) {
            $typeid = $tool->id;
        } else {
            $typeid = null;
        }
    } else {
        $typeid = $instance->typeid;
    }

    if ($typeid) {
        $typeconfig = lti_get_type_config($typeid);
    } else {
        //There is no admin configuration for this tool. Use configuration in the lti instance record plus some defaults.
        $typeconfig = (array)$instance;

        $typeconfig['sendname'] = $instance->instructorchoicesendname;
        $typeconfig['sendemailaddr'] = $instance->instructorchoicesendemailaddr;
        $typeconfig['customparameters'] = $instance->instructorcustomparameters;
        $typeconfig['acceptgrades'] = $instance->instructorchoiceacceptgrades;
        $typeconfig['allowroster'] = $instance->instructorchoiceallowroster;
        $typeconfig['forcessl'] = '0';
    }

    //Default the organizationid if not specified
    if (empty($typeconfig['organizationid'])) {
        $urlparts = parse_url($CFG->wwwroot);

        $typeconfig['organizationid'] = $urlparts['host'];
    }

    if (!empty($instance->resourcekey)) {
        $key = $instance->resourcekey;
    } else if (!empty($typeconfig['resourcekey'])) {
        $key = $typeconfig['resourcekey'];
    } else {
        $key = '';
    }

    if (!empty($instance->password)) {
        $secret = $instance->password;
    } else if (!empty($typeconfig['password'])) {
        $secret = $typeconfig['password'];
    } else {
        $secret = '';
    }

    $endpoint = !empty($instance->toolurl) ? $instance->toolurl : $typeconfig['toolurl'];
    $endpoint = trim($endpoint);

    //If the current request is using SSL and a secure tool URL is specified, use it
    if (lti_request_is_using_ssl() && !empty($instance->securetoolurl)) {
        $endpoint = trim($instance->securetoolurl);
    }

    //If SSL is forced, use the secure tool url if specified. Otherwise, make sure https is on the normal launch URL.
    if ($typeconfig['forcessl'] == '1') {
        if (!empty($instance->securetoolurl)) {
            $endpoint = trim($instance->securetoolurl);
        }

        $endpoint = lti_ensure_url_is_https($endpoint);
    } else {
        if (!strstr($endpoint, '://')) {
            $endpoint = 'http://' . $endpoint;
        }
    }

    $orgid = $typeconfig['organizationid'];

    $course = $PAGE->course;
    $requestparams = lti_build_request($instance, $typeconfig, $course);

    $launchcontainer = lti_get_launch_container($instance, $typeconfig);
    $returnurlparams = array('course' => $course->id, 'launch_container' => $launchcontainer, 'instanceid' => $instance->id);

    if ( $orgid ) {
        $requestparams["tool_consumer_instance_guid"] = $orgid;
    }

    if (empty($key) || empty($secret)) {
        $returnurlparams['unsigned'] = '1';

        //Add the return URL. We send the launch container along to help us avoid frames-within-frames when the user returns
        $url = new moodle_url('/mod/lti/return.php', $returnurlparams);
        $returnurl = $url->out(false);

        if ($typeconfig['forcessl'] == '1') {
            $returnurl = lti_ensure_url_is_https($returnurl);
        }

//.........这里部分代码省略.........

/**
 * Builds a standard LTI Content-Item selection request.
 *
 * @param int $id The tool type ID.
 * @param stdClass $course The course object.
 * @param moodle_url $returnurl The return URL in the tool consumer (TC) that the tool provider (TP)
 *                              will use to return the Content-Item message.
 * @param string $title The tool's title, if available.
 * @param string $text The text to display to represent the content item. This value may be a long description of the content item.
 * @param array $mediatypes Array of MIME types types supported by the TC. If empty, the TC will support ltilink by default.
 * @param array $presentationtargets Array of ways in which the selected content item(s) can be requested to be opened
 *                                   (via the presentationDocumentTarget element for a returned content item).
 *                                   If empty, "frame", "iframe", and "window" will be supported by default.
 * @param bool $autocreate Indicates whether any content items returned by the TP would be automatically persisted without
 * @param bool $multiple Indicates whether the user should be permitted to select more than one item. False by default.
 *                         any option for the user to cancel the operation. False by default.
 * @param bool $unsigned Indicates whether the TC is willing to accept an unsigned return message, or not.
 *                       A signed message should always be required when the content item is being created automatically in the
 *                       TC without further interaction from the user. False by default.
 * @param bool $canconfirm Flag for can_confirm parameter. False by default.
 * @param bool $copyadvice Indicates whether the TC is able and willing to make a local copy of a content item. False by default.
 * @return stdClass The object containing the signed request parameters and the URL to the TP's Content-Item selection interface.
 * @throws moodle_exception When the LTI tool type does not exist.`
 * @throws coding_exception For invalid media type and presentation target parameters.
 */
function lti_build_content_item_selection_request($id, $course, moodle_url $returnurl, $title = '', $text = '', $mediatypes = [], $presentationtargets = [], $autocreate = false, $multiple = false, $unsigned = false, $canconfirm = false, $copyadvice = false)
{
    $tool = lti_get_type($id);
    // Validate parameters.
    if (!$tool) {
        throw new moodle_exception('errortooltypenotfound', 'mod_lti');
    }
    if (!is_array($mediatypes)) {
        throw new coding_exception('The list of accepted media types should be in an array');
    }
    if (!is_array($presentationtargets)) {
        throw new coding_exception('The list of accepted presentation targets should be in an array');
    }
    // Check title. If empty, use the tool's name.
    if (empty($title)) {
        $title = $tool->name;
    }
    $typeconfig = lti_get_type_config($id);
    $key = '';
    $secret = '';
    $islti2 = false;
    if (isset($tool->toolproxyid)) {
        $islti2 = true;
        $toolproxy = lti_get_tool_proxy($tool->toolproxyid);
        $key = $toolproxy->guid;
        $secret = $toolproxy->secret;
    } else {
        $toolproxy = null;
        if (!empty($typeconfig['resourcekey'])) {
            $key = $typeconfig['resourcekey'];
        }
        if (!empty($typeconfig['password'])) {
            $secret = $typeconfig['password'];
        }
    }
    $tool->enabledcapability = '';
    if (!empty($typeconfig['enabledcapability_ContentItemSelectionRequest'])) {
        $tool->enabledcapability = $typeconfig['enabledcapability_ContentItemSelectionRequest'];
    }
    $tool->parameter = '';
    if (!empty($typeconfig['parameter_ContentItemSelectionRequest'])) {
        $tool->parameter = $typeconfig['parameter_ContentItemSelectionRequest'];
    }
    // Set the tool URL.
    if (!empty($typeconfig['toolurl_ContentItemSelectionRequest'])) {
        $toolurl = new moodle_url($typeconfig['toolurl_ContentItemSelectionRequest']);
    } else {
        $toolurl = new moodle_url($typeconfig['toolurl']);
    }
    // Check if SSL is forced.
    if (!empty($typeconfig['forcessl'])) {
        // Make sure the tool URL is set to https.
        if (strtolower($toolurl->get_scheme()) === 'http') {
            $toolurl->set_scheme('https');
        }
        // Make sure the return URL is set to https.
        if (strtolower($returnurl->get_scheme()) === 'http') {
            $returnurl->set_scheme('https');
        }
    }
    $toolurlout = $toolurl->out(false);
    // Get base request parameters.
    $instance = new stdClass();
    $instance->course = $course->id;
    $requestparams = lti_build_request($instance, $typeconfig, $course, $id, $islti2);
    // Get LTI2-specific request parameters and merge to the request parameters if applicable.
    if ($islti2) {
        $lti2params = lti_build_request_lti2($tool, $requestparams);
        $requestparams = array_merge($requestparams, $lti2params);
    }
    // Get standard request parameters and merge to the request parameters.
    $orgid = !empty($typeconfig['organizationid']) ? $typeconfig['organizationid'] : '';
    $standardparams = lti_build_standard_request(null, $orgid, $islti2, 'ContentItemSelectionRequest');
    $requestparams = array_merge($requestparams, $standardparams);
    // Get custom request parameters and merge to the request parameters.
//.........这里部分代码省略.........