/**
* Performs membership service request using an LTI Context object.
*
* If the context has a 'custom_context_memberships_url' setting, we use this to perform the membership service request.
* Otherwise, if a context is associated with resource link, we try first to get the members using the
* ResourceLink::doMembershipsService() method.
* If we're still unable to fetch members from the resource link, we try to build a memberships URL from the memberships URL
* endpoint template that is defined in the ToolConsumer profile and substitute the parameters accordingly.
*
* @param Context $context The context object.
* @param ResourceLink $resourcelink The resource link object.
* @param string $membershipsurltemplate The memberships endpoint URL template.
* @return bool|User[] Array of User objects upon successful membership service request. False, otherwise.
*/
protected function do_context_membership_request(Context $context, ResourceLink $resourcelink = null, $membershipsurltemplate = '')
{
$dataconnector = $this->dataconnector;
// Flag to indicate whether to save the context later.
$contextupdated = false;
// If membership URL is not set, try to generate using the default membership URL from the consumer profile.
if (!$context->hasMembershipService()) {
if (empty($membershipsurltemplate)) {
mtrace("Skipping - No membership service available.\n");
return false;
}
if ($resourcelink === null) {
$resourcelink = $dataconnector->get_resourcelink_from_context($context);
}
if ($resourcelink !== null) {
// Try to perform a membership service request using this resource link.
$resourcelinkmembers = $this->do_resourcelink_membership_request($resourcelink);
if ($resourcelinkmembers) {
// If we're able to fetch members using this resource link, return these.
return $resourcelinkmembers;
}
}
// If fetching memberships through resource link failed and we don't have a memberships URL, build one from template.
mtrace("'custom_context_memberships_url' not set. Fetching default template: {$membershipsurltemplate}");
$membershipsurl = $membershipsurltemplate;
// Check if we need to fetch tool code.
$needstoolcode = strpos($membershipsurl, '{tool_code}') !== false;
if ($needstoolcode) {
$toolcode = false;
// Fetch tool code from the resource link data.
$lisresultsourcedidjson = $resourcelink->getSetting('lis_result_sourcedid');
if ($lisresultsourcedidjson) {
$lisresultsourcedid = json_decode($lisresultsourcedidjson);
if (isset($lisresultsourcedid->data->typeid)) {
$toolcode = $lisresultsourcedid->data->typeid;
}
}
if ($toolcode) {
// Substitute fetched tool code value.
$membershipsurl = str_replace('{tool_code}', $toolcode, $membershipsurl);
} else {
// We're unable to determine the tool code. End this processing.
return false;
}
}
// Get context_id parameter and substitute, if applicable.
$membershipsurl = str_replace('{context_id}', $context->getId(), $membershipsurl);
// Get context_type and substitute, if applicable.
if (strpos($membershipsurl, '{context_type}') !== false) {
$contexttype = $context->type !== null ? $context->type : 'CourseSection';
$membershipsurl = str_replace('{context_type}', $contexttype, $membershipsurl);
}
// Save this URL for the context's custom_context_memberships_url setting.
$context->setSetting('custom_context_memberships_url', $membershipsurl);
$contextupdated = true;
}
// Perform membership service request.
$url = $context->getSetting('custom_context_memberships_url');
mtrace("Performing membership service request from context with URL {$url}.");
$members = $context->getMembership();
// Save the context if membership request succeeded and if it has been updated.
if ($members && $contextupdated) {
$context->save();
}
return $members;
}
