Array Returns Null

International Indian
1

I am using an array as global variable and after searching some data from a model, i am putting it in that array. And when i var_dump the array inside another function it returns null, even in view also it says null…

Note: by using the word global variable i mean that it is usable inside a particular controller only. Should be accessible by all its functions




   public $question=array();  // my global variable for this controller only

        

        public function actionCreate()

        {

            $db=new ExamMaster();

            

           if(isset($_POST['ExamMaster'])){

            

             //selecting em_id from exam_master table

              $db->attributes=$_POST['ExamMaster'];

              $crs=$_POST['ExamMaster']['course_id'];

              $sub=$_POST['ExamMaster']['subject_id'];

             

             

   

               $model = QuestionBankMaster::model()->findAll(array(

                 'select'=>array('question_id,question_entered','RAND()as rand'),  //RAND() is used for random selection

                 'condition'=>'course_id = :cid AND subject_id = :sid',

                 'params'=>array(':cid'=> $crs, ':sid'=> $sub),

                 'order'=>'rand', // we have to use order by RAND()

                 'limit'=>3,

                 )) ; 


              

             $i=0;

             

           foreach($model as $m)

             {

                  $object= new ExamQuestionMaster();

                  $object->em_id=$examID; 

                  $object->question_id=$m['question_id'];

                  $object->save();

                  $this->question[$i]=$m['question_entered'];

                  $i++;

             }

           

            // return $this->question;

             

             $this->redirect(array('displayquestion','crs'=>$crs,'sub'=>$sub));

           

               

       

               

            }//if closed

            

         

           

              $this->render('create',array('db'=>$db,'courseList'=>$courseList,'subjectList'=>$subjectList,'examList'=> $examList));    

        }

I am redirecting to the following function:—


public function actionDisplayquestion($crs,$sub)

        {

            //selecting the subject name from subject table and course name from course table

            $sname= Subject::model()->find(array(

               'select'=>'subject_name',

                'condition'=>'subject_id = :sid',

                'params'=>array( ':sid' => $sub),

            ));

             $cname= Course::model()->find(array(

               'select'=>'course_name',

                'condition'=>'course_id = :cid',

                'params'=>array( ':cid' => $crs), 

            ));

     

        echo var_dump($this->$question);  // It returns null???


            $this->render('displayquestion',array('course'=>$cname,'subject'=>$sname));

And here is the view of Displayquestion




<?php


echo CHtml::link('Home',array('Site/Index')) . '<br/>';


echo 'Subject: '. $subject['subject_name'];

echo '</br>';

echo 'Course: '. $course['course_name'];

echo '</br>';

echo '<table class="myqustion">';


$limit=count($this->question);

//echo $limit;

for($i=0; $i<$limit; $i++)

{

  echo '<tr><td>';

  echo '<b>Question.'. $i+1 .'</b>' .$this->question[$i];

  echo '</td></tr>';

  echo '<tr><td>';

  echo '</br>';

  echo '<hr>'; 

  echo '</br>';

  $i++;

}

echo '</table>';


?>
2

Because you are redirecting and the $question variable is being reset when the new request (from the redirect) comes in.

3

How to pass it then? i hav to display it in the view. please tell me

4

Can you explain what you’re trying to do? It looks like you’re trying to display a random set of questions for a given course and subject. If examId is unique, you can pass that to the display function and return the list of questions from that.





...


$this->redirect(array('displayQuestion', 'examId' => $examId, 'courseId' => $crs, 'subjectId' => $sub));

}


public function actionDisplayQuestion($examId, $courseId, $subjectId)

{

	$course= Course::model()->findByPk($courseId);

	$subject = Subject::model()->findByPk($subjectId);

	

	$examMaster = ExamQuestionMaster::model()->findByPk($examId);

	$questions = $examMaster->questions; // You need relations setup correctly to do this.


	$this->render('displayQuestion',array(

		'questions'=> $questions,

		'course'=> $course,

		'subject'=>$subject

	));

}

Matt

5

U gave me an idea, after i get data from the form, I will redirect directly to the displayquestion function and also pass course and subject value. And all the operations will be done inside actionDisplayquestion and rendered directly… :slight_smile:

6

where do i declare the variable, so that it does not get deleted/renewed/null after i take the value inside it and use redirect/render????

and Many many thanks for giving me idea…

7

You’ll have access to it if you render the view. The redirect causes a new request and it’s hitting a different action so the array is never populated.

8

Ok, now i get it… Thanks a lot