reselbob/AdvancedOops02_TS

A project that demonstrates using generics in TypeScript

Typescript Programming Using Generics

The purpose of this project is to demonstrate how to use generics when programming in TypeScript.

The use case for this project is document processing class. The document being processed is an implementation of either the IWebDocument or IPrintDocument interface. There are three example classes that use generic variables in various ways. The document processing classes are DocumentProcessorV1, DocumentProcessorV2, and DocumentProcessorV3

• DocumentProcessorV1 is an example of using a single generic variable T that represents the document to process. The generic variable T is constrained to accept only an implementation of an IWebDocument or an IPrintDocument interface.
• DocumentProcessorV2 is an example of using a generic variable at the class's method level only.
• DocumentProcessorV3 is an example of using two generic variables, T and V. Generic variable T represents the document to be processes. The generic variable V represents a confirmation of type IWebConfirmation or IPrintConfirmation. The confirmation is returned by the class's process(document: T) : V method. The generic variable T is constrained to accept only an implementation of an IWebDocument or an IPrintDocument interface.

System requirements

This project has the following requirements

• Node.js and npm need to be installed on the machine running the project.

Getting the code up and running

Execute the following instruction to install the project's dependencies from NPM.

npm install

Exercising the code

Exercising an example of a class that uses one generic variable

You can view the code that the following instruction exercises here. The class being exercised is DocumentProcessorV1.

npx ts-node ./src/example-01.ts

You'll get output similar to the following:

Processing as a web document: https://incompatible-nickname.org/
Processing as a print document with page count: 39

Exercising a class that declares a generic variable at the method level

You can view the code that the following instruction exercises here. The class being exercised is DocumentProcessorV2.

npx ts-node ./src/example-02.ts

You'll output similar to the following:

Processing as a web document: https://tender-sweatshop.name/
Processing as a print document with page count: 95

Exercising a class that uses two generic variables

The following instruction that you can view here exercises a class that takes two generic variables. One variable represents the document that the DocumentProcessor class is to process. The other generic variable represents the confirmation that is returned by the class method that processes the document.

The class being exercised is DocumentProcessorV3.

npx ts-node ./src/example-03.ts

You'll get output similar to the following:

Processing as a web document: https://eager-loop.name/
{
  webResult: {
    timeStamp: 2024-03-31T12:56:21.520Z,
    documentId: '6e0a6c5c-3821-4eb3-88d7-60019e639883',
    title: 'causa amitto arceo tenetur',
    url: 'https://eager-loop.name/'
  }
}
Processing as a print document with page count: 28
{
  printResult: {
    timeStamp: 2024-03-31T12:56:21.525Z,
    documentId: '64d0d367-c289-485f-bc46-b05b9810e460',
    title: 'caterva absum adnuo quos',
    pageCount: 28
  }
}