Error when trying to inject a service into an angular component “EXCEPTION: Can't resolve all parameters for component”, why?

Question

I\'ve built a basic app in Angular, but I have encountered a strange issue where I cannot inject a service into one of my components. It injects fine into any of the three o

Answer 1

In my case, the reason was the following:

• my injectable service A extended another class B
• B had a constructor which required an argument
• I hadn't defined any constructor in A

As a consequence, when trying to create an object A, the default constructor failed. I have no idea why this wasn't a compile error.

I got it fixed by simply adding a constructor in A, which correctly called B's constructor.