Trying to get property of non-object? PHP/Codeigniter

I have been literally pulling my hair out with this one and its beginning to delay the rest of my project and it really is getting me down.

I am trying to populate a pull down using values taken from a database table so that if in the future the user wants to add more options to the pull down they can add them to the table in the database.

I am using the Codeigniter platform (PHP) using MVC design pattern.

Here is the error message I am getting:

A PHP Error was encountered Severity: Notice Message: Trying to get property of non-object Filename: views/submit.php Line Number: 139

My Model function is this here which retrieves the rows from the table called "Staff". This works fine!

function retrieve_values()
{
    $query = $this->db->get('staff');

    if ($query->num_rows() > 0) 
    { 
        //true if there are rows in the table
        return $query->result_array(); //returns an object of data
    }

    return false;
}

This is the controller function which receives the parameter and passes it to my view. This works fine!

public function displayform()
{

    //Checks if a user is logged in, if they are not they get redirected -
    if ( $this->session->userdata('name') == FALSE || $this->session->userdata('access_level') == FALSE)
    {
        redirect ('site/index');// to home page
    }

    //Stores the returned array in instance called "formdata" which will be passed to the view to be used in pulldown menu
    $page['formdata']=$this->submit_model->retrieve_values();

    //This loads the form 
    //Instance of "page" in array "page" specifies the file name of the page to load
    $page['page'] = 'submit';
    $this->load->view('template', $page );

    return;
}

This is the part of the view which is causing the problem: I am using a foreach and then echoing the instances of the array into the option.

<select>
    <?php foreach ($formdata as $row) { ?>
        <option value="<?php echo $row->staff_id; ?>"><?php echo $row->name; ?></option>
    <?php } ?>
</select>

printr() of the variable $formdata shows that it contains these values:

Array (
    [0] => Array (
        [staff_id] => 1
        [n开发者_JS百科ame] => Cardiology Nurse
    )
    [1] => Array (
        [staff_id] => 2
        [name] => Radiology Nurse
    )
    [2] => Array (
        [staff_id] => 3
        [name] => Scrub Nurse
    )
    [3] => Array (
        [staff_id] => 4
        [name] => Circulating Nurse
    )
    [4] => Array (
        [staff_id] => 5
        [name] => Nurse
    )
    [5] => Array (
        [staff_id] => 6
        [name] => Training Nurse
    )
    [6] => Array (
        [staff_id] => 7
        [name] => Physiologist
    )
    [7] => Array (
        [staff_id] => 8
        [name] => Radiographer
    )
    [8] => Array (
        [staff_id] => 9
        [name] => Consultant
    )
    [9] => Array (
        [staff_id] => 10
        [name] => Radiologist
    )
    [10] => Array (
        [staff_id] => 11
        [name] => Cardiologist
    )
    [11] => Array (
        [staff_id] => 12
        [name] => Anaethestist
    )
    [12] => Array (
        [staff_id] => 13
        [name] => Non-medical Staff
    )
)

formdata is an array of arrays, not objects, so simply change in your view:

<option value="<?php echo $row->staff_id; ?>"><?php echo $row->name; ?></option>
// to
<option value="<?php echo $row['staff_id']; ?>"><?php echo $row['name']; ?></option>

You've used result_array, which means you're going to get an array of arrays, instead of an array of objects. You can either modify your view to have this:

<option value="<?php echo  $row['staff_id']; ?>">
    <?php echo  $row['name']; ?>
</option>

instead of

<option value="<?php echo $row->staff_id; ?>">
    <?php echo $row->name; ?>
</option> 

or you can change $query->result_array() to $query->result() in the model.