Hey, I’m Chen! A Web & App Developer.

Whether you’re new to React or you are recently migrating from class components (this late?), you might not be familiar with how useEffect works.

Actually, you might be using it still from other existing (or copied 😉) code, but have no idea (or just a small idea) what’s actually happening.

In this post we’ll dive in to this very flexible hook, some example, and some real, common use-cases.

As React apps grow bigger and more complex, performance becomes more and more of a problem. As components become larger and contain more and more sub-components, rendering becomes slow and turns into a bottleneck.

How do we tackle this? If you haven’t used useMemo and useCallback, we can start with those.

When developers first start their journey, sometimes syntax is easy. You’ve memorized a few commands, classes, and method names, and you can make simple applications quite easily. Also, there is plenty of docs and tutorials online - as well as Stack Overflow - surely copying-and-pasting your way through would be enough, right?

Let’s try to answer the question: how to start approaching problem solving for any given task?

When prototyping UI designs or code, we often need images to put in places when we have no finalized images in the design, or in order to test out different sizes and colors when only some are provided.

I find myself needing to find an image to use when developing websites and apps often, and finding a mock image to upload is time consuming - not to mention leaves possibly unwanted files in your code or design.

So what do we do?

Enter: placeholder.photo.

Flutter is an amazing framework for app development, and gaining popularity every second. Being component and composition based, and with the fact that it includes many built-in widgets to work with, it’s really easy to create beautiful widgets, either simple or complex.

Today we’ll be learning how to create a real-world case widget for updating a numeric value - a pitch-knob-like control. Like the ones you can usually find in a studio. It will also support letting the finger go to keep rolling in the same direction, and using the velocity it was left with.