Angular Services

Angular and observable objects

If you look at the browser, you will find that the Collector page is empty and there are a bunch of errors in the console. That is because we are trying to work with Observable objects without including the related library into our project. In our Angular 2 seed project, there is a place for vendor packages:

src/vendor.browser.ts

Open this file and simply uncomment the line that imports the RxJS library:

// src/vendor.browser.ts 
// ... 
// RxJS 5 
import 'rxjs/Rx'; 
//... 

Now we can investigate how Observable objects work here. Checking the http object, the task of the get() method is obvious. It is a simple HTTP GET request and returns a response. But what about those map() functions? Where do they come from and what ...