Creating a custom RxJS operator

By following the other recipes in this chapter, I have to ask if you’ve become a fan of RxJS yet? Have you? Well, I am. And in this recipe, you’re going to level up your RxJS game. You’re going to create your own custom RxJS operator that just taps into any observable stream and logs the values on the console. We’ll call it the logWithLabel operator.

Getting ready

The app that we are going to work with resides in start/apps/chapter05/rx-custom-operator inside the cloned repository:

1. Open the code repository in your code editor.
2. Open the terminal, navigate to the code repository directory, and run the following command to serve the project:

   npm run serve rx-custom-operator
   

   This should open the app in a new browser tab. If you click the Start Stream button while you have the DevTools open, you should see the following:

   

   Figure 5.12: The rx-custom-operator app running on http...