Services going down is a part of life, so every app needs to gracefully handle what happens when things aren't working as expected. When errors do occur, RxJS enables you to switch over to another stream of your choosing to load any alternative data you'd like to display.
Instructor: [00:00] now we'll break our URL and when I click, our data will fail to load. You'll see errors in the console. The way we usually handle this is by .catching the error. This will give us an error and will want to switch over to an observable.
[00:18] The observable that we'll create is going to be an observable of an object that has a name of "Failed," and maybe a frowny face for good measure. We'll hit Save here, clear out console, click, and you can see that it properly failed. My image service also captured the failure to load an unnamed image.
[00:39] Now the cool thing about this is if this fails to load, we can switch over to a different request entirely. I can do a create loader, and then we'll load the other person and make sure and fix the URL. Put the G there, and two will be C-3PO. We'll hit Save there, clear out the console, click, and you'll see that we gracefully handled the error and made a separate request over to loading C-3PO.
[01:07] If I fix this by fixing the URL when hitting Save, then going back and clicking, it'll load Luke. Inside of this catch, simply return an observable that gives us an object with a name on it and an image on it, too, if you wanted. Then, you can gracefully handle any errors that may come your way...