How To Add New Product Fields?

[webego]

After searching through the Zen Cart forums for help on how to add new product fields, I came across a thread started by crazy_chris which shows how to add a new field to the existing products table. Later in that thread zskiman shows how to add fields into a separate table, which is a great idea to future proof your efforts for later upgrades etc. My intention here is to share what I have learned from both these posts and add my own input which I think simplifies the end usage of your new fields.

Any changes to existing code or completely new code are shown in red (what out for , too).

So lets gets started...

1. Create a new table to hold your additional fields and give it a name i.e. products_extra_stuff and add the products_id field (so we can relate our new table to the existing products table) and whatever fields you wish to add i.e. products_colour
   
   
2. Open includes/database_tables.php and add your new table to the list of definitions i.e.define('TABLE_PRODUCTS_EXTRA_STUFF', DB_PREFIX . 'products_extra_stuff');
   
   
3. Open admin/includes/modules/product/preview_info.php and change the following lines:
   
   (line 26 for me)
   p.products_sort_order, pdex.products_colour
   from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_PRODUCTS_EXTRA_STUFF . " pdex
   where p.products_id = pd.products_id and p.products_id = pdex.products_id
   
   
4. Open admin/includes/modules/product/collect_info.php and change the following lines :
   
   (line 12 for me)
   $parameters = array('products_name' => '',
   'products_description' => '',
   …
   'master_categories_id' => '',
   'products_colour' => ''
   );
   
   (now line 60 for me after the above edit)
   p.products_price_sorter, p.master_categories_id, pdex.products_colour
   from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " .
   TABLE_PRODUCTS_EXTRA_STUFF . " pdex
   where p.products_id = '" . (int)$_GET['pID'] . "'
   and p.products_id = pd.products_id and p.products_id = pdex.products_id
   
   
5. In the same file (collect_info.php) insert your form fields to collect your new data along with the rest:
   
   (line 305 for me as I wanted to insert just below product name)
   <!-- BOF - Additional field added -->
   <tr>
   <td class="main"><?php echo 'Colour '; ?></td>
   <td class="main"><?php echo zen_draw_separator('pixel_trans.gif', '24', '13') . '&nbsp;' .
   zen_draw_input_field('products_colour', $pInfo->products_colour, zen_set_field_length(TABLE_PRODUCTS_EXTRA_STUFF, 'products_colour')); ?></td>
   </tr>
   <!-- EOF - Additional field added -->
   
   
6. Open admin/includes/modules/update_product.php and add the following lines to process both new products and the editing of existing ones:
   
   (line 153 for me)
   ////////////// MY ADDED FIELDS ////////////////////
   $sql_data_array = array('products_colour' => zen_db_prepare_input($_POST['products_colour']));
   
   if ($action == 'insert_product') {
   $insert_sql_data = array('products_id' => $products_id);
   
   $sql_data_array = array_merge($sql_data_array, $insert_sql_data);
   
   zen_db_perform(TABLE_PRODUCTS_EXTRA_STUFF, $sql_data_array);
   } elseif ($action == 'update_product') {
   zen_db_perform(TABLE_PRODUCTS_EXTRA_STUFF, $sql_data_array, 'update', "products_id = '" . (int)$products_id . "'");
   }
   /////////////////////////////////////////////
   
   
7. In order to make the data from your new field(s) available to add to the product page open inludes/modules/pages/product_info/main_template_vars.php and change the following lines:
   
   (line 55 for me)
   p.products_discount_type, p.products_discount_type_from, p.products_sort_order,
   p.products_price_sorter, pdex.products_colour
   from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_PRODUCTS_EXTRA_STUFF . " pdex
   where p.products_status = '1'
   and p.products_id = '" . (int)$_GET['products_id'] . "'
   and pd.products_id = p.products_id and p.products_id = pdex.products_id
   
   (line 101 for me amongst products name, model and description)
   $products_colour = $product_info->fields['products_colour'];
   
   
8. Finally, to display the data from your new field(s) open includes/templates/YOUR_TEMPLATE/templates/tpl_product_info_display.php and add something similar to the following:
   
   (place wherever you wish your new field to be displayed)
   <!--bof Product Colour -->
   <?php
   if ($products_colour != '') {
   ?>
   <div id="productColour" class="productGeneral"><strong>Colour: </strong><?php echo $products_colour; ?></div>
   <?php
   }
   ?>
   <!--eof Product Colour -->

And that my friends is it...Enjoy!