public function tryEnroll($sid, $class) { //Get Cid $cid = Course::first()->getCid($class); // Check if Student has taken the class. $x = ClassesTaken::where('id', $sid)->where('cid', '=', $cid)->first(); if ($x) { return array("You have already taken this course."); //return false; } else { $list = Course::where('cid', '=', $cid)->first()->requisites; //if list is empty, return null; //if(!($list)) //return array(); $results = array(); foreach ($list as $row) { //IF Prerequisite OR Prerequisite, check both if ($row->ORprid) { $get1 = ClassesTaken::find($sid)->where('cid', '=', $row->prid)->first(); $get2 = ClassesTaken::find($sid)->where('cid', '=', $row->ORprid)->first(); //If student hasn't taken both courses if (!($get1 || $get2)) { $x = CourseInfo::find($row->prid)->subjectNumber(); $y = CourseInfo::find($row->ORprid)->subjectNumber(); $result = "You are missing " . $x . " or " . $y . " prerequisites."; array_push($results, $result); //return false; } } elseif ($row->prid) { $hit = ClassesTaken::find($sid)->where('cid', '=', $row->prid)->first(); if (!$hit) { $y = CourseInfo::find($row->prid)->subjectNumber(); $result = "You are missing " . $y . " prerequisite."; array_push($results, $result); //return false; } } } return $results; //return true; } }