Zen Cart Discount Preview

A Zen Cart™ mod which allows you to display order total discounts on the shopping cart page (and in the shopping cart sidebox, if desired). In this way, discounts which are normally not visible until the second page of checkout are visible earlier.

Works with my Better Together and Quantity Discounts contributions, the built-in Zen Cart Group Discount module, and my Discount Chooser, Discount Spender, BOGO Discount, Combination Discounts, Big Spender, Big Chooser, Manufacturer Discount, Case Discounts, Table Discounts, and Frequency Discounts extensions.

Note that Discount Preview does not support Newsletter Discount. As an alternative, see this tip in the MailChimp installation page.

Relevance: Zen Cart™ 1.5.x. Please specify your Zen Cart version when ordering.

Current Version: 1.15 (for Zen Cart 1.5.x), 1.15_subtotal (for Zen Cart 1.5.x) (version history)

Support Thread: My commercial software is not supported on the Zen Cart forum. Please email me questions instead.

Installed Cost: $200.00 (Professional installation by That Software Guy)


Would you like to ask me questions before buying? I'm happy to help likely purchasers make the right decision. Please use my contact form.



See it Live: Go to my demo shop and add ten of any item to your cart (excluding gift certificates). You will immediately see the discount because of Discount Preview. Without Discount Preview, the discount would not be visible until the second page of checkout.

You can also see this in the Discount Preview Video:

Bugs: click here

Incompatibilities: This software will not work with Ajax add-to-cart or Ajax checkout mods that do not reload the page when changing the cart contents or checking out. Please do not order this software if you are using these mods.

This software will not display a discounted price in the header if you are using a mod to display the shopping cart total in the header. I can modify it to do this if you purchase installation, but it won't do it by default since displaying a cart summary in the header is a modification and not part of Zen Cart.

Screenshots: See Discount Preview in the wild! Discount Preview Styling can be done to match your template.

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Overview:

Regular Shopping Cart Page

Shopping Cart Page with Discount Preview

Shopping Cart Page with Discount Preview AND Revised Subtotal

Shopping Cart Sidebox With Discount Preview Extension

Installation Instructions:

1. Back up everything! Try this in a test environment prior to installing it on a live shop.
2. Copy the contents of the unzipped folder to the root directory of your shop.
   The names of these files reflect a template name of "custom." If you are using a different template name, please change file paths using "custom" to use your template name instead. Note: If you are using Zen Cart 1.5.5 or higher, your template name will be "responsive_classic" if you have not changed it.
3. If you use the Shipping Estimator feature to display an estimate of shipping costs in the cart (i.e. 2= Display as Listing on Shopping Cart Page), you MUST change the file includes/modules/shipping_estimator.php. Look for a line that says

          require(DIR_WS_CLASSES . 'order.php');
   

   and change this to

          require_once(DIR_WS_CLASSES . 'order.php');
   

   (Note that if you are using Ajax Shopping Cart by Numinix, you will have to make the same change in includes/modules/ac_shipping_estimator.php - as well as many other changes to the files in includes/modules/YOUR_TEMPLATE to make the display work.)
   
   You will know if you have the Shipping Estimator enabled by checking Admin > Configuration > Shipping Estimator Display Settings for Shopping Cart.
4. If you have also ordered Checkout Candy or Checkout Candy for Combination Discounts from me, you will have to merge the files includes/templates/custom/templates/tpl_shopping_cart_default.php
includes/templates/custom/css/shopping_cart.css
5. As of version 1.12: If you are still using a non-responsive template, after installing the files under "includes", cd to the non_responsive_template directory and install that set of files.
6. The shopping cart sidebox will not display the discount information when the shopping cart page is being displayed. If you use the shopping cart sidebox, you must configure your cart not to displayed this sidebox on the shopping cart page. Go to Admin > Configuration > Layout Settings > Shopping Cart Box Status, and set this value to 2.

Installation Problems:

1. Forgetting to rename the folder from includes/modules/custom to includes/modules/YOUR_TEMPLATE if your template is not named "custom"
2. If you see the message that looks something like,

   "Fatal error: Cannot redeclare class order in /var/www/web4/web/includes/classes/order.php on line 20"

   you need to look for statements that do

   require(DIR_WS_CLASSES . 'order.php');
   

   and change them to

   require_once(DIR_WS_CLASSES . 'order.php');
   

   This must be done in the following places:
   • includes/modules/shipping_estimator.php
   • includes/modules/payment/paypalwpp.php (if you are using PayPal Website Payments Pro).
3. Got a blank page? Review the guidelines for Debugging a blank page in Zen Cart
4. Are you using embedded taxes (such as a VAT)? First of all, make sure the discount is correct on the checkout payment page if you have not already done so. If it is not, please read my Notes on Taxes. Once you have this correct, go back to Discount Preview, and make these changes:
   • Edit includes/templates/custom/templates/tpl_shopping_cart_default.php and look for the 2 blocks that say "UK VAT". Uncomment them. (Note that the first "UK VAT" block in each file assumes that your default class id is 1; if it is not, change the first parameter in the call to zen_get_multiple_tax_rates accordingly.)
   • Make the same changes to includes/templates/custom/sideboxes/tpl_shopping_cart.php
   • I have seen one case where logging in but instead of checking out, going back to the shopping cart page, causes the discount to be displayed without tax. Please test this case, which is an unusual but not impossible workflow. If this happens to you, change the first UK VAT block in both files noted above to:

      // build tax groups for UK VAT people who have embedded taxes
      if ($order->info['tax'] == 0) {
        $order->info['tax_groups'] = array();
        if (isset($_SESSION['customer_zone_id'])) {
           $zone = $_SESSION['customer_zone_id'];
           $country_id = $_SESSION['customer_country_id'];
        } else {
           $zone = -1;
           $country_id = -1;
        }
        $order->info['tax_groups'] = zen_get_multiple_tax_rates(1,$country_id,$zone);
     

5. If you are using Zen Cart 1.5.5 with the new Responsive Template, version 1.12 (with or without recalculated subtotal) has the updated CSS for you.
   It looks like this:
   

Tips

1. If you've never installed a Zen Cart mod before, please read my Guide to Mod Installation on Zen Cart.
2. IMPORTANT! If you are using Quantity Discounts, and you're using the marketing suggestions on the product info page, please be sure you have the latest code:

   <?php
     $value = "ot_quantity_discount.php"; 
     include_once(zen_get_file_directory(DIR_WS_LANGUAGES . $_SESSION['language'] . 
             '/modules/order_total/', $value, 'false'));
     include_once(DIR_WS_MODULES . "order_total/" . $value);
     $discount = new ot_quantity_discount();
     echo '<div class="content" id="discountPolicy">'; 
     echo '<h2>' . STORE_POLICY . '</h2>'; 
     echo $discount->get_html_policy();
     echo '<br /></div>'; 
   ?>
   

   (i.e. both "include" statements should be "include_once")
   
3. To place a message at the top of the shopping cart page near the undiscounted total, edit the file customize the file includes/languages/english/shopping_cart.php, and set TEXT_INFORMATION to something like "See bottom of page for discount information."
   
4. If you use the shopping cart sidebox, you should define the following new CSS class in includes/templates/custom/css/stylesheet.css

   .cartBoxDiscount {
           text-align: right;
           font-weight: bold;
           }
   

   This is how your discount information will appear in the shopping_cart sidebox.
   
5. If you have any problems after installing this mod, the first thing you should do is delete includes/templates/custom/sideboxes/tpl_shopping_cart.php Although this works well with a freshly installed cart, it is possible that the logic in this file will not interoperate with other modifications you have made. You may need to turn off the shopping cart sidebox or simply use some text in here telling the customer to go to the shopping cart page to see discount information. The next tip describes how to do this.
   
6. If you are using the shopping cart sidebox but would prefer not to indicate the amount of the discount (or have interoperability problems as described above), customize the file includes/templates/template_default/sideboxes/tpl_shopping_cart.php, copying it to includes/templates/custom/sideboxes/tpl_shopping_cart.php At the bottom of the file, right before the line

      $content .= '</div>';
   

   insert the line

      $content .= CART_INFORMATION_SIDEBOX;
   

   If you have used CSS styling in the main page of shopping_cart.php, you can make the sidebox look the same by using this line instead:

      $content .= '<div id="cartInstructionsDisplay" class="content">';
      $content .= CART_INFORMATION_SIDEBOX; 
      $content .= '</div>';
   

   CART_INFORMATION_SIDEBOX is a string you have defined in includes/languages/english/extra_definitions/discount_preview.php like this:

   define('CART_INFORMATION_SIDEBOX','Discounts displayed in shopping cart');
   

   
   
7. Want to show off your discounts even more using red lettering, yellow background or some other effect? See my Highlighting your Discounts tip.

Showing the revised subtotal