This repository is for all kind of small experiments with different languages, tools and technologies

Currently I'm in the process of better understanding different approaches of layered architectures. Here are some helpful links I found during the understanding process:

• https://www.codeproject.com/Articles/493389/Four-ways-of-passing-data-between-layers
• http://richard.jp.leguen.ca/tutoring/soen343-f2010/tutorials/implementing-table-data-gateway/

Example Code

cd ./layered-architecture/non-uniform
npm install
# init db
node init-db.js
# run the example code
node index.js

• Good for small to medium sized applications, which are heavily database driven
• An active record object contains: model properties, getters and setters, domain logic and sql operations
• Domain layer and data access layer is the same class

• Is an improvement compared to the active record pattern, because it splits the active record class in two separate classes
  • domain class (properties, getter/setter, domain logic)
  • data mapper class (sql operations, creation of domain class)
• Problem: It's not clear in which layer (domain layer or data access layer) the data mapper belongs. He has a dependency on the domain class in the domain layer and to the sql connection in the data access layer.

• The domain layer and the data access layer is divided properly
• the table data gateway in the data access layer has no dependency to the domain layer
• the data mapper in the domain layer is responsible to convert between the models and the data

Example Code

cd ./layered-architecture/table-data-gateway
npm install
node index.js # run the example code
node reset-db.js # reset the db

Mission: Understand the repository pattern better and especially what is are the differences to the table data gateway pattern.

• https://medium.com/@krzychukosobudzki/repository-design-pattern-bc490b256006#.k88e8lfgg
• http://blog.gauffin.org/2013/01/data-layer-the-right-way/
• http://blog.gauffin.org/2013/01/repository-pattern-done-right/