angular5-course/src/app/shared/data-storage.service.ts

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

import { RecipeService } from '../recipes/recipe.service';
import { Recipe } from '../recipes/recipe.model';

@Injectable()
export class DataStorageService {
    readonly baseUrl: string = 'https://my-recipe-book-cb837.firebaseio.com/';

    constructor(private httpClient: HttpClient, private recipeService: RecipeService) {}

    storeRecipes() {
        return this.httpClient.put(this.baseUrl + 'recipes.json', this.recipeService.getRecipes());
    }

    fetchRecipes() {
        this.httpClient.get<Recipe[]>(this.baseUrl + 'recipes.json').subscribe(
            recipes => {
                this.recipeService.replaceRecipes(recipes);
            }
        )
    }
}