无法运行foreach循环

Question

i have a trouble with my foreach loop, it always shows warning that is: Invalid argument supplied for foreach(), can you have a look and help me solve this problem. This is my controller:

function prod_detail($id_sp){
    $this->load->model('product_model');
    $data['prod_detail'] = $this->product_model->getProdDetailByProdId($id_sp);
    $data['prod_errors'] = $this->product_model->getProdDataError($id_sp);
    $data['error_repairing'] = $this->product_model->getProdDataErrorRepairing($id_sp);
    $data['rows']= $this->membership_model->getUserData();
    $data['main_content'] = 'backend/home/manproduct/prod_detail_view';
    $this->load->view('includes/admin/template', $data);
}

This is my model:

function getProdDataError($id_sp){
    $this->db->where('id_sp', $id_sp);
    $this->db->where('status', 0);
    $query = $this->db->get('loi');
    if($query->num_rows()>0){
        foreach ($query->result() as $row){
            $data[]=$row;
        }
        return $data;
    }
}
function getProdDataErrorRepairing($id_sp){
    $this->db->where('id_sp', $id_sp);
    $this->db->where('status', 1);
    $query = $this->db->get('loi');
    if($query->num_rows()>0){
        foreach ($query->result() as $row){
            $data[]=$row;
        }
        return $data;
    }
}

And here is my view:

if($ud->status==0){
                echo 'Hoạt động';
            }else if($ud->status==1){
             echo '<b>Lỗi<br><ul></b>';
             foreach ($prod_errors as $err) {
                 echo '<li>'.$err->ten_loi.'</li>';
             }
             echo '</ul>';
         }else if($ud->status==2){
             echo '<b>Đang sửa lỗi<br><ul></b>';
             foreach ($error_repairing as $err) {
                 echo '<li>'.$err->ten_loi.'</li>';
             }
             echo '</ul>';
         }else if($ud->status==3){
             echo 'Chưa lắp đặt';
         }

It's ok when $ud->status==1 but it shows a warning message when $ud->status==2. btw, i use codeigniter to develop my web, can you help?

Answer 1

try this (adding checks on $prod_errors/$error_repairing before trying to iterate them)

if($ud->status==0)
{
                echo 'Hoạt động';
}else if($ud->status==1)
{
    echo '<b>Lỗi<br><ul></b>';
    // first check $prod_errors exists and is not null before iterating it
    if (isset($prod_errors)) 
    {
        foreach ($prod_errors as $err) 
        {
             echo '<li>'.$err->ten_loi.'</li>';
        }
    }
    else{
        echo "No Data found";
    }
    echo '</ul>';
}else if($ud->status==2)
{
    echo '<b>Đang sửa lỗi<br><ul></b>';
    // first check $error_repairing exists and is not null before iterating it
    if (isset($error_repairing)) 
    {
        foreach ($error_repairing as $err)
        {
             echo '<li>'.$err->ten_loi.'</li>';
        }
    }
    else{
        echo "No Data found";
    }
    echo '</ul>';
}else if($ud->status==3)
{
     echo 'Chưa lắp đặt';
}