Cloning a Shipping Module

Note: These instructions are for Zen Cart 1.5.8 and higher. For Zen Cart 1.5.7 and lower, please see Cloning a Shipping Module in 1.5.7 and below.

You can create new Shipping Module by making a clone of the closest matching Shipping Module to what you are trying to do.

As an example, we will consider the flat shipping module.

Shipping Modules have 2 parts:

The code file is located in:
/includes/modules/shipping/flat.php

The language file is located in:
/includes/languages/english/modules/shipping/lang.flat.php

To clone this module, for example, to flatfree.php you would:

• copy flat.php to flatfree.php
• copy lang.flat.php to lang.flatfree.php

Note: Be sure the filename you choose does not have an underscore (_) in it.

Next, you need to change all occurrences of the strings flat and FLAT as follows:

These identifiers are case sensitive.

These words are written separately or within the constants such as:

class flat {
... 
$this->code = 'flat';
... 
$this->title = MODULE_SHIPPING_FLAT_TEXT_TITLE;

becomes

class flatfree {
...
$this->code = 'flatfree';
...
$this->title = MODULE_SHIPPING_FLATFREE_TEXT_TITLE;

Be sure to make this change in the remove() function as well.

Once you have cloned the module then you can alter how it calculates shipping to the method that you need. This calculation is done in the quote() method.

Flat does not have complicated logic to compute a quote; it uses a single figure.

To see examples of quote calculations that are more complex, you might look at the items.php Shipping Module.

Cloning or creating a Shipping Module to function the way you need it is not too difficult if you just work through the steps on paper then recreate the same steps within the quote() function.

These forum threads might also give you ideas:

• Thread: Additional Shipping Option - Flat Rate Per Item
• Thread: How do I set 2 flat shipping rates to 2 different zone?