/**
  * Index page
  * 
  * @param void
  * @return null
  */
 function index()
 {
     js_assign('invoicing_precision', INVOICE_PRECISION);
     $this->wireframe->addBreadCrumb(lang('Invoicing'), assemble_url('admin'));
     $this->wireframe->addBreadCrumb(lang('Number Generator'), assemble_url('admin_invoicing_number'));
     // prepare javascript variables and counters for preview
     $pattern = Invoices::getInvoiceNumberGeneratorPattern();
     list($total_counter, $year_counter, $month_counter) = Invoices::getDateInvoiceCounters();
     $total_counter++;
     $year_counter++;
     $month_counter++;
     $variable_year = date('Y');
     $variable_month = date('n');
     $variable_month_short = date('M');
     $variable_month_long = date('F');
     js_assign('pattern_variables', array(INVOICE_VARIABLE_CURRENT_YEAR => $variable_year, INVOICE_VARIABLE_CURRENT_MONTH => $variable_month, INVOICE_VARIABLE_CURRENT_MONTH_SHORT => $variable_month_short, INVOICE_VARIABLE_CURRENT_MONTH_LONG => $variable_month_long, INVOICE_NUMBER_COUNTER_TOTAL => $total_counter, INVOICE_NUMBER_COUNTER_YEAR => $year_counter, INVOICE_NUMBER_COUNTER_MONTH => $month_counter));
     $generator_data = $this->request->post('generator');
     if (!is_foreachable($generator_data)) {
         $generator_data = array('pattern' => Invoices::getinvoiceNumberGeneratorPattern());
     }
     // if
     $this->smarty->assign(array('generator_data' => $generator_data));
     if ($this->request->isSubmitted()) {
         $errors = new ValidationErrors();
         $posted_pattern = array_var($generator_data, 'pattern', null);
         if (!trim($posted_pattern)) {
             $errors->addError(lang('Pattern is required'), 'pattern');
         }
         // if
         if (strpos($posted_pattern, INVOICE_NUMBER_COUNTER_TOTAL) === false && strpos($posted_pattern, INVOICE_NUMBER_COUNTER_YEAR) === false && strpos($posted_pattern, INVOICE_NUMBER_COUNTER_MONTH) === false) {
             $errors->addError(lang('One of invoice counters is required (:total, :year, :month)', array('total' => INVOICE_NUMBER_COUNTER_TOTAL, 'year' => INVOICE_NUMBER_COUNTER_YEAR, 'month' => INVOICE_NUMBER_COUNTER_MONTH)), 'pattern');
         }
         // if
         if ($errors->hasErrors()) {
             $this->smarty->assign(array('errors' => $errors));
         } else {
             Invoices::setInvoiceNumberGeneratorPattern($posted_pattern);
             flash_success('Pattern for invoice number generator is saved');
             $this->redirectTo('admin');
         }
         // if
     }
     // if
 }