JavaScript *

From time to time, developers need to establish communication between several browser tabs to be able to send messages from one tab to another and receive responses. We have also faced this need at some point.

Some solutions already exist (like, for instance, BroadcastChannel API). However, its browser support leaves a lot to be desired, so we decided to use our own library. When the library was ready, that functionality was no longer required. Nevertheless, another task emerged: communication between an iframe and the main window.

On closer examination, it turned out that two-thirds of the library would not have to be changed — only some code refactoring was necessary. The library is a communication PROTOCOL that can work with text data. It can be applied in all cases in which text is transferred, such as iframes, window.open, worker, browser tabs or WebSocket.

How it works

Currently, the protocol has two functions: sending messages and subscription to events. Any message in the protocol is a data object. For us, the main field in that object is type, which tells us what kind of message it is. The type field is an enum with the following values:

Code splitting. Code splitting is everywhere. However, why? Just because there is too much of javascript nowadays, and not all are in use at the same point in time.

JS is a very heavy thing. Not for your iPhone Xs or brand new i9 laptop, but for millions(probably billions) of slower devices owners. Or, at least, for your watches.

So — JS is bad, but what would happen if we just disable it — the problem would be gone… for some sites, and be gone "with sites" for the React-based ones. But anyway — there are sites, which could work without JS… and there is something we should learn from them...

In this article, I decided to describe how the functionality of selecting and displaying photos on a specific place on the map was implemented in our photo service gfranq.com. The photo service does not work now.

Since we had a lot of photos in our service and sending requests to database every time the viewport changes was too resource-intensive, it was logical to divide the map into several areas that contain information about the retrieved data. For obvious reasons, these areas have rectangular shape (although hexagonal grid was considered too). As the areas become more spherical at large scales, elements of spherical geometry and tools for it were also considered.

In this article, the following issues were raised:

• Storing and retrieving photos from the database and caching them on the server (SQL, C#, ASP.NET).
• Downloading necessary photos on the client side and saving them to the client cache (JavaScript).
• Recalculation of photos that must be hidden or shown when the viewport changes.
• Elements of spherical geometry.

With the appearance of ECMAScript 2015, an avalanche of features came; some of them make you mad, and others are pleasant surprises, like meeting an old friend after a long time.

Some features are related to metaprogramming. What is that? I'm not very eloquent, so let's turn to our friend, Wikipedia.

Google shut down their social media platform Google+ on April 2, 2019. It’s hard to find some technical article that hasn’t mentioned the end of Google’s social network era. But, a high level of consistency in connectivity within services of the company had received scant attention. In this article I would like to share my thoughts on the internal way of Google services consistency and what it means for Google API users when it comes to a Google+ shutdown.

Have you heard about memoization? It's a super simple thing, by the way,– just memoize which result you have got from a first function call, and use it instead of calling it the second time - don't call real stuff without reason, don't waste your time.

Skipping some intensive operations is a very common optimization technique. Every time you might not do something — don’t do it. Try to use cache — memcache, file cache, local cache — any cache! A must-have for backend systems and a crucial part of any backend system of past and present.

It's 2019! Everybody thinks they know code splitting. So - let's double check!

What does code splitting stand for?

In short – code splitting is just about not loading a whole thing. Then you are reading this page you don't have to load a whole site. When you are selecting a single row from a database – you don't have to take all.
Obvious? Code splitting is also quite obvious, just not about your data, but your code.