JavaScript for Line of Business Applications

It’s been almost a year since we started using AngularJS in production here at Localytics. We began by experimenting with a small piece of our site and were so happy with it that we rewrote our entire analytics dashboard product — overhauling nearly four years’ worth of legacy production code — in Angular.

With a surprising lack of documentation or blog posts on real-world use of Angular on production Rails applications, we’ve had to be fairly creative with how we organized our code and integrated the two technologies. Most documentation on Angular code organization and workflow assumes a JavaScript/Grunt-centric worldview, and it was hard to see how we would introduce Grunt into our Rails kingdom, where Sprockets and Capistrano reign supreme. Meanwhile, we’ve seen a few cute examples on how to structure a fresh Angular/Rails hello-world seed app, but odds are, if you’re in production, you’ve already got a big steaming Rails app chugging away and don’t enjoy the luxury of starting from scratch with rails new my-todo-list-cookbook-twitter-seed-demo-world-app. So we thought we’d share some of the practices and tricks we’ve come up with at Localytics to get Angular running on Rails.

* Code Organization and the Asset Pipeline
* Testing
* Choosing the Right Tool
* Conclusion

Although JavaScript and Java sound and look similar they are very different in their details and philosophies. Here I try to compare the two languages regardless of their libraries and frameworks. The goal is that you as a Java developer get an understanding of what JavaScript is and how it differs from Java. One hint: you can use jsfiddle.net to try out some of the snippets here or any JavaScript.

In the last times I’ve been practicing with Sails.js, Nodejs basedframework, and in a short time I feel myself very productive and with realtime skills done in a natural way!

I still don’t find myself comfortable with NoSql databases (and I don’t know if I ever) and Sails.js offers the good ORM Waterline to be used with MySql too.

I think that I’ve a kind of obsession with form validation everytime I try a new environment I test how I can achieve it in a more elegant way.

But my main point still holds: to end up with the best product we’re capable of creating together, we need to be able to change directions, and we should expect to change directions several times.

We don’t have (or want) the luxury of moving from “requirements gathering” to “specification” and then to “design” and “development” phases. All of those tasks are happening in parallel, all the time. As our user researchers and product designers continue their own iterative processes, the “ideal product” will become clearer and clearer. When presented with a new or revised product goal, the engineering team needs to be ready and able to quickly move toward that evolved goal.

A few months ago, we were starting to build out a couple new products, and as is always the case when starting a new project, we had to decide whether to keep using our old tools, or make some changes. In particular, we had recently hired a number of front-end engineers who weren’t too keen on our Google Closure-based JavaScript code.

Ext.NET is an advanced ASP.NET (WebForms + MVC) component framework integrating the cross-browser Sencha Ext JS JavaScript Library.

WHO
is it for?

If you are looking to build a rich, modern web application with cutting edge web technologies, unparalleled cross-browser compatibility and an advanced MVC architecture then Ext.NET is for you!

WHY
should you use it?

Ext.NET is built for developers, by developers. We provide hundreds of Demos in our Examples Explorer. Need a little support? Check out our Developer Bundles.

Use the browser's History API for Ember.js routing and fallback to hash on older browsers. Just update your server routes and include the above file with your Ember.js web app.

The resolver will allow your application to use Ember's native implementation of the HTML5 History API for routing. That means that the /#/ part of the URL can be replaced with a single /. Now your speedy Ember web app can benefit from even more beautiful URLs.

And the best part? All your old hash URLs still work! The resolver will automatically redirect to the updated hashless version.

I’ve been a big fan of Sencha’s ExtJS since I started using it several years ago. When I was first exposed to the framework in its v2.0 days, it was a breath of fresh air compared to anything else out there. It had a well-documented, powerful framework and a comprehensive set of widgets. The grid widget alone scratched enough itches that the rest of the framework was gravy.

I haven’t been able to use it on any projects, though, for a couple years, but I have tried to stay up to date on the releases. Unfortunately for Sencha, in the intervening years, the internet has started to catch up and I’ve been taking a much more critical eye to ExtJS. There are still several good parts to ExtJS, but there are also a lot of bad things that will limit its suitability for any future projects.

* The Good Parts

* The Bad Parts

* The Sweet Spot

* What To Do

 I’m here to talk about context or the “this” keyword in JavaScrtipt. It’s a small piece of the JavaScript language, but it’s really important, and it hangs people up sometimes because it’s a little counterintuitive how “this” works in JavaScript.

For background, JavaScript has a keyword "this," as do, C++, Java, C# and many other languages. The problem is that the JavaScript version works rather differently, and this is a source of pain and confusion for many JavaScript developers. Since it's an important part of the language, we should spend some time thinking about it.

Sometimes I get involved in discussions on twitter and Facebook related to development. This week I ended up sending a link to an old(ish) twitter thread explaining when to favor Promises/Callbacks and when to use Signals/Events for asynchronous operations. I think this topic deserves further explanation.

Why: JavaScript is a functional language but its standard libraries miss a lot of the functional goodies we are used to from other languages. Here underscore comes to the rescue.

Why: Concurrency is hard. Callbacks can get out of hand pretty quickly even more so when they are nested. Promises make writing and reading concurrency code simpler.

Why: Your scripts need to be in modules, cleanly separated from each other. If you don’t have an asset pipeline want to load your modules asynchronously or just want to manage your modules from your JavaScript require.js is for you.

Why: Proper dependency management is a tough nut to crack and it is even harder to be pleasantly used (I am looking at you, maven).

Why: Repetitive tasks need to be automated. If you plan to use grunt and bower consider using yeoman which combines both into a workflow.

Why: There are tons of chart or visualization libraries out there but d3 takes a more general approach. It defines a way of thinking, a way of manipulating the document based on data and data alone. It treats the DOM as part of your web application. Your visualization is a part of your document and not just a component you can forget about after creating it. This general approach allows you to create arbitrary visualizations not just charts.

Why: jQuery is almost ubiquitous and this is not by chance. It provides a great foundation and helps in many common scenarios.

With the addition of the HTML 5 FileReader interface, client-side processing of file uploads is now possible using JavaScript alone. This is great news for anyone aiming to keep their web application’s functionality running in the browser instead of the server.

My current project involves an Ember.js web application and a JSON+HAL API, and we recently wanted to let administrative users upload an XML file, sourced from a different system, to make filling out a form easier. We didn’t want to upload the file to the API for processing on the server. Following is an example illustrating how we handled the file upload in our Ember.js app, and how we could make this work with a few other file formats.