Angular 2 DI undefined class

Question

Currently I'm trying to inject some kind of settings class into the application.

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';

@Injectable()
export class Settings {

    private apiUrl: string = '';
    private location: string = '';
    private language: string = 'en';

    constructor() {
        if(localStorage.getItem('apiUrl')) this.apiUrl = localStorage.getItem('apiUrl');
        if(localStorage.getItem('location')) this.location = localStorage.getItem('location');
        if(localStorage.getItem('language')) this.language = localStorage.getItem('language');
    }

    getApiUrl(): string {
        return this.apiUrl;
    }

    getLocation(): string {
        return this.location;
    }

    getLanguage(): string {
        return this.language;
    }

    setApiUrl(apiUrl: string): void {
        this.apiUrl = apiUrl;
        localStorage.setItem('apiUrl', apiUrl);
    }

    setLocation(location: string): void {
        this.location = location;
        localStorage.setItem('location', location);
    }

    setLanguage(language: string): void {
        this.language = language;
        localStorage.setItem('language', language);
    }

}

This is my settings class...

What I try to do next is inject in through the whole application (since settings will be used a lot). For this I think the best way is to do this with the bootstrap() function. So this is my bootstrap function:

bootstrap(AppComponent, [Settings])

I did insert it into the constructor in the service I want to use the apiUrl setting:

@Injectable()
export class UserService {
    constructor(private _settings: Settings, private _http:Http) { }
}

but for some reason when running the application I got an error in the UserService saying that the first parameter of the constructor (_settings) is undefined..

I've been trying different things but didn't find a working solution yet..

Answer 1

Did you forget to import the Settings class in your UserService?

You're not listing the top of your UserService...

Answer 2

Ok, so after trying many things I found out what the problem was.

I had a TS file containing all the exports for each folder I have..

I do have this core folder, containing the Settings class and a file called core.ts.

When I did: import { Settings } from './core'; it didn't work. But when I do: import { Settings } from './core/settings , it does work.