Entity Class Generator

Recently I needed to create 20+ classes to represent entities returned from an API endpoint. Each class having about 40 to 50 or more attributes. So rather than creating all these classes manually I wrote this little application to generate the classes for me. The classes are generated in TypeScript

Prequisites

• Nodejs (tested on 6.x)

Example

An HTTP GET call to http://localhost/api/items returns a list of items where an item has the attributes id, name and created_date. So the returned list looks like

[
  {"id":1, "name": "Lightsaber", "created_date": "2016-05-01"},
  {"id":2, "name": "Tunic", "created_date": "2016-05-01"},
  {"id":3, "name": "Kyber Crystal", "created_date": "2016-05-01"},
]

In order to use the data from the API, one of the first things I do is assign them to a data structure in this case the data structure will be an array of object Items. Therefore in the front-end (I am using Angular 2 at the moment) I have typescript class as follows

class Items {
   id: number;
   name: string;
   createdDate: string;
}

The above class is easy enough to type out but when you need to create 20+ classes with each class having 40+ attributes, its time to think of a more productive approach. This application is my productive approach.

How it works

• Make an HTTP GET request to an API endpoint that returns a list of objects.
• Get the first element of this list
• Loop through the element attributes and create a class file based on the type of attribute.

NOTE: This was created for personal use and to support my very specific use case.

How to use it

• Create a file called config.json in the same folder as the index.js file. The index file should be created as follows. The fields are self explanatory I think.

{
	"host": "192.168.1.5",
	"port": 80,
	"apiRoot": "/api/",
	"entities": [
		"items",
		"users"
	],
	"method": "GET",
	"headers": {
		"Content-Type": "application/json"
	}
}

In the file above the users endpoint will be http://192.168.1.9/api/users.

• Create a folder called generated-classes. This is where the classes generated by the program will be created.
• Run the application by executing the command node index.js

NOTE: The config.json and generated-classes folders are in .gitignore.