This weekend I decided to play with the new kid on the block - Facebook's Recoil library for managing state. I did the trivial counter example to see how it works. It's pretty simple idea so I wondered how much it takes to replicate its features. I found the exact answer - 70 lines of code. Obviously, my implementation didn't cover everything but it was fun so I decided to share my findings.

(A side note: I did not look at the code of Recoil. I didn't want to be bias on how to write my version.)

If your users deal with images (photos, product images, etc.) it will be great if they have the ability to apply some basic editing after upload, e.g. adjust brightness and contrast for sharper view, crop, add some text, etc. However, if image editing is not the primary feature of your product, the profit from investment in such secondary feature won't cover the costs. Integrating a 3rd party image editor appears to be a wiser choice.

I hope you know about currying. If not then please read this book. It’s basically a process of calling a function with less parameters than it expects. Ok, not exactly calling the function but prepare another function that will run the original one. Some people call the returned function higher-order factory function. Really powerful concept.

By my opinion one of the biggest problems in programming are dependencies. If you want to have a good well written application you should avoid dependencies between your modules/classes. There is a design pattern which could help and it's called Dependency Injection (DI). It allows you to inject objects into a class, instead of creating them there.

I'm a big fen of the MVC pattern. I like the idea to store my data in one place and be able to get it fast. In most of my projects I used a class called Storage for similar purpose. It supports a multi-language data saving, so I decided to share it with you.

Last few years the JavaScript frameworks are big part of our web sites. I strongly recommend the usage of tools like jQuery or MooTools, because they will save you a lot of time and problems. These days I needed to create a keyboard shortcut for one of the projects that I'm working on. I wanted to catch the Ctrl+Shift+F9 combination. It was just a few lines of code and I decided to share it with you.

"Look under the hood of Google Chrome in this comics interpretationof key engineering decisions, by Scott McCloud."

1. Moving background layer - sometimes you want to move the background layer. But by default it's locked. So just click twice on the layer and choose "OK" in the popup message. The layer will be transformed to normal layer.