New object instance with DI in constructor

manpreet Best Answer 3 years ago

I’m new to Inonic/Angular.

My question is, I have this class that I’ve created which uses DI:

import { HttpServiceProvider } from './../providers/http-service/http-service';

export class HttpWrapper{

    private _url: string;
    private _port: number;
    private _api: string;
    private _headers: Map;

    constructor(private httpServie: HttpServiceProvider, url: string, port: number, api: string){
        this.url = url;
        this.port = port;
        this.api = api;
    }

When I want to create a new instance of this class I need to provide ‘HttpServiceProvider’ to the constructor. What is the right way to initiate new object of this kind? (without providing the ‘HttpServiceProvider’).

manpreet 3 years ago

You can initialize a parameter of a class with null then it will not give you error on initialization of new Object

EXAMPLE:

export class HttpWrapper {

    private _url: string;
    private _port: number;
    private _api: string;
    private _headers: Map<string, string>;

    constructor(private httpServie: HttpServiceProvider = null, url: string, port: number, api: string){
        this.url = url;
        this.port = port;
        this.api = api;
    }