Decorator

Decorator Pattern

This directory contains examples of the Decorator design pattern implemented in TypeScript. The Decorator Pattern is a structural design pattern that allows behavior to be added to individual objects, either statically or dynamically, without affecting the behavior of other objects from the same class. It is used to extend the functionality of classes in a flexible and reusable way. If at any point you would like to obtain and run these files refer to the root README.md found here.

Conceptual Example

The conceptual example can be found in conceptual.ts and ran from conceptual.js. The TypeScript files contains the code and explanations of what each element does in the design pattern.

Real-World Example

The real world example I chose to do is working with data, reading and writing to/from, files. The DataSource is the base component which all concrete componenets and the base decorator implement. The concrete implementation we have is FileDataSource which is a file for the data. Next we have our decorators. The base decorator is DataSourceDecorator which defines the basics of the decorator. Then our concrete decorator is EncryptionDecorator which writes encoded data and decodes read data. These classes are used with client funnctions that can write/read public data and write/read secret (using EncryptionDecorator) data.

NOTE to run this you must first run:

npm install

This ensures that @types/node is installed such that you can use fs which is required to work with files. After that is installed you can compile and run as normal.