Angular is extensible. Not only can we easily create our own custom components (so that we're not restricted to using ready-made components from third parties), but we can also create our own attribute directives so that we're not restricted to what Angular gives us out of the box.

I'll leave some of the custom things we can do in Angular, such as custom attribute directives, custom pipes (we'll see what pipes are in the next section), and custom form validation, until Chapter 14, Advanced Angular Topics. We'll be taking a look at form validation in Chapter 10, Working with Forms. There's a good reason why I chose to lump all of the advanced stuff that is covered in this book into one chapter—to give you time to digest the basic stuff first. By the time the advanced chapter comes along, near the end of the book, you'll be ready and primed to more easily absorb that information.