[Blog] Extension Framework Game Plan

_posts/2016-04-05-extension-framework-game-plan.md

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+---
+layout: post
+cover: 'assets/images/general-cover-3.jpg'
+title: Extension Framework Game Plan
+tags: docs
+subclass: 'post tag-docs'
+categories: 'elixir'
+author: 'Pikender'
+navigation: true
+logo: 'assets/images/nectar-cart.png'
+---
+
+>
+The post belongs to _NectarCommerce and Extension Framework Awareness_ Series
+>
+1. _[NectarCommerce Vision](http://vinsol.com/blog/2016/04/08/nectarcommerce-vision/)_
+1. **Extension Framework Game Plan**
+1. Introduction to MetaProgramming
+1. Running Multiple Phoenix Apps Together
+1. Ecto Model Schema Extension
+1. Ecto Model Support Functions Extension
+1. Phoenix Router Extension
+1. Phoenix View Extension
+1. Extension Approach Explained
+1. Developer Experience and Workflow developing Favorite Product Extension
+1. Developer Experience and Workflow testing Favorite Product Extension
+
+## What will be NectarCommerce
+
+>
+Off-the-shelf Opensource E-commerce application for building online store.
+>
+Provides an Extension Framework to support features not included in core as extensions.
+>
+Strives for un-obstrusive parallel development of NectarCommerce and Extensions
+
+NectarCommerce is committed to provide a ready-to-use e-commerce solution but definition of 100% is different under different business domains. It aims to solve common use-cases as part of the project and relying on extension framework to tap the rest.
+
+## Extension Framework Game Plan
+
+Let's validate and list the capabilities needed in Extension Framework through an **extension** which provides feature **to mark a product as user's favorite**
+
+_**Favorite Product Extension Requirements:**_
+
+- **Ability to mark and unmark a Product as favorite**
+  - a View _probably_ showing all products with Ability to mark/unmark product as favorite
+  - a controller action preparing the view
+  - a route exposing the controller / view through Web
+  - a controller action handling mark product as favorite
+  - a route exposing the controller / view through Web
+  - a controller action removing product from the list of favorites
+  - a route exposing the controller / view through Web
+  - a model interfacing with database to store product favorited by user
+  - a migration to create join table in database
+  - a join table storing product\_id and user\_id
+- **Showing All Products favorited by a User**
+  - association in User to get favorite products
+  - a View showing list of Favorite Products
+  - a controller preparing the view
+  - a route exposing    the controller / view through Web
+- **Showing Users who favorited a particular Product**
+  - association in Product to get users who favorited
+  - a View showing list of Users who favorited
+  - a controller preparing the view
+  - a Route exposing the controller / view through Web
+- Ability to test the integration of above mentioned requirements
+
+**Let's break the above requirements into _two_ groups**
+
+- Model layer changes
+- Request layer changes
+
+### Model Layer Changes
+
+- Ability to mark and unmark a Product as favorite
+  - a model interfacing with database to store product favorited by user
+  - a migration to create join table in database
+  - a join table storing product_id and user_id
+- Showing All Products favorited by a User
+  - association in  User to get favorite products
+- Showing Users who favorited a particular Product
+  - association in Product to get users who favorited
+
+_**translates to**_
+
+- Ability to mark and unmark a Product as favorite
+  - **New Ecto Model** with user\_id and product\_id fields
+  - **Ecto migration** to create join table storing product_id and user_id
+- Showing All Products favorited by a User
+  - **extending User schema** to have associations as needed
+  - **support functions in User Model** to retrieve all products favorited by a user
+- Showing Users who favorited a particular Product
+  - **extending Product schema** to   have associations as needed
+  - **support functions in Product Model** too retrieve all users who favorited a product
+
+
+### Request Layer Changes
+
+- Ability to mark and unmark a Product as favorite
+  - a View probably showing all products with ability to mark/unmark product as favorite
+  - a controller action preparing the view
+  - a route exposing the controller / view    through Web
+  - a controller action handling mark product as favorite
+  - a route exposing the controller / view through Web
+  - a controller action removing product from the list of favorites
+  - a route exposing the controllerontroller / view through Web
+- Showing All Products favorited by a User
+  - a View showing list of Products
+  - a controller preparing the view
+  - already route exposing the controller / view through Web
+- Showing Users who favorited a particular Product
+  - a View showing list of Users
+  - a controller preparing the view
+  - a route exposing the controller / view through Web
+
+_**translates to**_
+
+- Ability to mark and unmark a Product as favorite
+  - a **View** probably showing all products with ability to mark/unmark product as favorite
+  - a **controller** with index / create / delete action
+  - a **route** exposingposing index / create / delete action
+- Showing All Products favorited by a User
+  - a **View** showing list of Products
+  - a **controller** preparing the viewew
+  - a **route** exposing the controller / view through Web
+- Showing Users who favorited a particular Product
+  - a **View** showing list of  Users
+  - a **controller** preparing the view
+  - a **route** exposing throughe controller / view through Web
+
+## What we need
+
+- way to extend schema definitions for existing models
+- way to add new functions in existing models
+- way to add routes
+- way to add controller / views for newly added routes
+- way to extend views
+- way to reuse layouts
+- way to reuse already available routes
+
+## How we attempt to solve
+
+- Elixir Metaprogramming
+- Elixir umbrella app dependencies to share and reuse code among Nectar & Extensions using ExtensionManager
+- Extensions as Phoenix project leveraging NectarCommerce
+
+## Bridging the Gap
+
+**Next Posts** would refer the *Favorite Product Extension* to help co-relate and reveal the challenges & solutions implemented to propose an Extension framework.
+
+>
+_Our aim with these posts is to start a dialog with the Elixir community on validity and technical soundness of our approach. We would really appreciate your feedback and reviews, and any ideas/suggestions/pull requests for improvements to our current implementation or entirely different and better way to do things to achieve the goals we have set out for NectarCommerce._
+
+We look forward for your support and feedback on [twitter](https://twitter.com/NectarCommerce) and [github](https://github.com/vinsol/nectarcommerce/pull/47)
+
+_Enjoy the Elixir potion !!_