No results after implementing ProductService class

[DanielRunningen]

Hello,

I've been following along with the tutorial and have just completed Module 9, the section where our product list is separated form the component and initially hard-coded into the service. I've gone through the section a few times now and have not had success in getting the products to show up again.

At first I was having the issue NullInjectorError: No provider for ProductService!. I added the ProductService class to the providers of app.module.ts, which seemed to fix that issue, but I don't recall that being necessary from the tutorial, and the provided 'checkpoint' example for Module 9 doesn't have that line.

The issue following this, however, does not show any of the products in ProductService. This is also true when I compile directly from the example code from Module 9. No products are listed and no errors appear in the console. I'm not sure what I might be doing wrong?

[DanielRunningen]

Update as I was gathering info for this issue!

I went into my product.service.ts file to remove the product information (so putting it here would be less bulky) and lo and behold making a comment in the file fixed it.

The comment itself didn't fix it obviously, but causing an update in the product.service.ts file must have forced angular to update the reference to the class after fixing the null ref issue. So if you finish with Module 9 and have a similar issue, either restart the app or force an update to the service file and you should be fine.

Caching is a wonderful thing...

[DanielRunningen]

Also good to note, you definitely do not need to have a providers line in app.module.ts if the products are now loading, so I'm still very confused, but it works lol

[DeborahK]

Glad you were able to resolve the issue. Depending on the browser you are using, it is possible to turn caching off to minimize this issue.

Regarding the providers array, you should no longer need that. Services are now registered using the providedIn property of the @Injectable decorator. I cover this in detail in the "Services and Dependency Injection" module.

Hope this helps!

[DanielRunningen]

@DeborahK - thanks, that's what I thought. Still not sure why adding it partially fixed the issue.