JavaScript for Line of Business Applications

Who doesn't love to write better code? In this article I will list 10 simple and quick JavaScript tips that will help beginners improve their code quality. You might know some of these already. In case you didn't feel free to buy me a beer later.

I want to show the listens for each episode and then show the average range in which those listens are falling.

In order to show this, I need to be able to calculate the standard deviation based on the number of listens for each episode shown in the graph. And while I could reach for an existing JavaScript statistics library, like one of the many listed here, I decided it would be more fun to learn how to do this myself.

Writing performant code is absolutely critical. Poorly written JavaScript can significantly slow down and even crash the browser. On mobile devices, it can prematurely drain batteries and contribute to data overages. Performance at the browser level is a major part of user experience which is part of the 10up mission statement.

Contents:

* Performance
* Design Patterns
* Code Style & Documentation
* Unit and Integration Testing
* Libraries

Introduction to the compiling/interpreting process by making a simple calculator application in JavaScript.

This article will perform a basic overview of this process by showing how to write an interpreter for a simple language that we can use for a calculator application.

Step 1: The Lexer

Step 2: The Parser

Step 3: The Evaluator

By bubbles I mean the UI controls browsers display validation errors in. For whatever reason, we developers (or more likely our designer colleagues) have a deep-seated desire to style these things. But unfortunately we can’t, as zero browsers provide styling hooks that target these bubbles.

So what’s a developer to do? Well, although browsers don’t allow you to customize their bubbles, the constraint validation spec does allow you to suppress the browser’s bubble UI and build your own. The rest of the article shows you how to do just that.

The following is my step-by-step refactoring path, including close look at some MVC-ish solutions. You can use it to get ideas on revamping your own spaghetti app, and/or to see how to approach design of <canvas>-based app, specifically. Each step is made as a separate commit in fabricjs.com repo on github.

The unique challenges faced in writing third-party JavaScript revolve around the same-origin policy. Because the JavaScript file is based on a different domain to its host, inbuilt browser security places restrictions on cookie use and client-side/server communication. 

By using jQuery for prototyping, you will be deferring full browser support issues until a little later in the project timeline, but by then you should have gained a better understanding of the unique problems inherent when writing third-party JavaScript.

JavaScript applications keep getting bigger, more complex, and harder to debug. Without stacktraces, how are we expected to find, decipher, and fix our bugs?