At the heart of Miva Merchant is it’s extraordinarily flexible module system. As a testament to the robust module API that Miva Merchant provides, it is worth noting that almost every feature within a fresh installation of Miva Merchant is provided by modules distributed with the core package! The writers of Miva Merchant actually use their own module API!

But in general what is referred to as a Miva Merchant Module is a third party plug-in that you can add to Miva Merchant to extend or enhance the functionality. In short, Miva Merchant Modules add features to your online store.

There are 7 main classifications of Miva Merchant Modules, but the features that they can provide are essentially only limited by the skills and imagination of the developer creating the module. Modules will generally fall into the following “API” categories, but their features can vary widely:

• Currency Modules: Create currency formatting rules for your store
• Tax Modules: Implement special tax calculations for your store
• Shipping Modules: Implement special shipping calculations for your store
• Payment Modules: Provide payment collection capabilities such as credit cards, etc.
• Utility Modules: Create back-end utilities in your store accessible in the Miva Merchant administration
• Fulfillment Modules: Perform certain “fulfillment” actions when an order is placed; for example communicating that order to an external fulfillment house or your back-office systems
• System Modules: Run any time a page is displayed or an action occurs in your store. System modules can change the way an action is performed such as changing prices when a product is added to the basket, or even add their own actions that occur based on store clicks and inputs from your store.
• Component Modules: Create or modify existing displays within your store.

Any module can implement any combination of the above features to create a nearly unlimited set of features and functions in your store. For example, a module that provides discounts might both alter the displays in your store as well as prevent more than one “discounted” item from being added to the basket if that is the purpose of a special sale in your store.

In general, Miva Merchant 5 modules don’t “conflict” with one another unless they’re operating on the same actions at the same time as another module. These conflicts can generally be understood by knowing the features each module provides. For example if you have a module that provides “buy one get one free” pricing and another that provides “tiered pricing by customer”, it’s natural to expect these two modules might conflict. But neither of these would likely conflict with another module that provides free shipping at checkout if the order total is greater than some amount.