# Extensibility

To stay "pluggable" the architecture must be highly "extensible". Consider the following recommendations while implementing an application:

* **Use classes for multi-part, complex feature implementations**. Classes allow isolating functionality under the shared context while splitting the functionality into logical functions. For example: React components, GraphQl query-builders.<br>
* **Use functions for single-purpose, isolated feature implementations** where context sharing is not required. For example request and data processors, utility functions.

To allow plugin nesting (stacking), the data-structures for class members and functions must be carefully chosen according to the following guidelines:

* **For a list of conditions resulting in different outcomes use maps or objects**. Try to avoid "if-else" or "switch" cases as they are tougher to read and extend.<br>
* **For a list of items dependant on order or "SortedList" utility** from `@scandipwa/framework/src/util/SortedMap`. Try to avoid objects as they do not guarantee the proper sorting of entries, and arrays as they do not expose a way to insert after or before a specific entry.<br>
* Try to **avoid returning complex values (objects of a class)** if possible. The common complex values are: React elements, GraphQl Fields. For example: instead of returning a wrapper with rendered items in it, consider splitting that logic into smaller parts:
  * wrapper rendering function
  * a function returning the array of items wrapped by a wrapper
  * a function for each wrapped item rendering

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Read more on Extensibility in the [documentation](https://docs.scandipwa.com/building-your-app/extensions).
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