Recording of Webinar Introduction to React & Typescript available

Last Saturday I had the chance to run my first webinar, thanks to my friend and ex-colleague Lalit Kale and the folks from Indiamentor.

We discussed about React, pros and cons, why should someone use it instead of AngularJS (for example eh, no puns intended) and how to setup the dev environment. Then I showed a small demo of a hello-world-like application made with Typescript using Visual Studio Code.

Later the same day, the Indiamentor team has also uploaded on Youtube the complete recording:

Unfortunately due to some obscure technical reasons, the streaming software decided to stop updating the screenshare after a couple of slides, so in the video you won’t see the second part of the presentation. However, I used Google Presentations to create my deck, so here’s the link ūüôā

I had a very good time preparing the slides and talking to the audience, even if I wasn’t actually seeing anyone. I am really starting to think that maybe I could prepare some coding or software architecture lessons and begin running¬†some (online) courses.

Data pagination with NodeJS and React


here’s the link to the GitHub repo.

Some time ago, in one of my articles I showed a way to paginate your data using WebAPI on the server and AngularJS on client-side. Funnily enough I wrote that post exactly two years ago, I just noticed it while writing this. Well, turns out a lot of people is still searching for it, so now, after two years, I have decided to write another couple of notes but with a different tech stack.

Yes, of course, I could have used the same backend from the old article, but where’s the fun in that?

Enter NodeJS and React!

So, let’s start with the server first. As you can see from the sources, I used Typescript this time. To be honest, I don’t feel “safe” while writing Javascript code, even with lots of unit tests. Having some form¬†of “strongly-typed” language is a little bit of relief, at least for the .NET coder in me.

The architecture is very simple: we have an express application with just one Route ( /api/products/ ) exposing a GET action which reads from a Repository the paged list of available products. Due to the nature of the example, I decided to keep things simple and not add any kind of IoC container, just to avoid to overcomplicate the code.

I have also added two middlewares, one to console.log() all the incoming requests and the other to allow CORS for a¬†specific¬†domain ( eg. our client application ). In case you need to refresh your memory, here’s a nice article about NodeJS middlewares.

The core concept that you can see from the Products API is to return an object that exposes the list of Products along with some infos like the total number of pages, the total Products count and the current page number.

Let’s talk about the client now.

I was definitely not disappointed discovering that the learning curve for React is actually very, very low. Coming from the Angular world, I was expecting more difficulties, but in a matter of hours I have been able to setup my dev env with Typescript ( wanna know how?  ) and start coding my components.

Oh yes, don’t miss my webinar this Saturday! I’ll do a quick introduction about Typescript and React.

Ideally, I could have served the client part directly from the NodeJS application, but I preferred to keep everything separated. Yeah, I had to activate CORS, but it’s not really a big deal. Also, it makes everything more “microservices-oriented“, which is becoming more and more an hype these days. In my mind, for that kind of architecture you should have two servers talking, but bear with me.

In our small demo, the client is using a service to read the products, displays them in a table and renders a pager at the bottom. As you can easily notice, I am using the fetch() polyfill to perform the AJAX request.

Also, to make things more interesting,¬†in this case I am using an IoC container, Inversify, to handle dependencies. However, since Components are instantiated directly by the React engine we cannot use constructor injection but have to revert to property injection….which in this case is handled by the @lazyInject decorator. I’ll write another post about the subject in the upcoming future.

For now, if you enjoy the example, don’t forget to write a comment!

Webinar: introduction to React & Typescript – again!

Due to the huge amount of registrations, me and the folks at Indiamentors have decided to postpone the Introduction to React & Typescript webinar to Saturday September 17th at 6:30 IST .

As I told you before, this webinar is going to be an introduction about React,  how to setup your dev environment and how to write your first piece of React code.
I’ll show you a small¬†demo and at the end we’re going to have a nice Q&A session.

Here’s the agenda:

  • Why React?
  • Let‚Äôs get started!
  • React Components
  • Properties and State
  • Webpack
  • Demo

Make sure to register and reserve your seat!

Building an Angular 2 + Typescript application template

Last time I showed you a way to create a Typescript application template. Now we can use that as a starting point for an Angular 2 application.

As usual, I have created a GitHub repo with the necessary sources and the list of steps to perform. At the end of the process, we’ll¬†get our friendly¬†web server showing a nice “lorem ipsum” coming from an Angular2 Component¬†.

Also in this case the core of the system is gulpfile.js which exposes a bunch of tasks:

  1. ‘clean’ : as the name may suggest, this task is used to clear the www folder from all the external libraries, the transpiled .js files and sourcemaps
  2. ‘libs’: this will copy the depencencies to a specific folder
  3. ‘build’: this will execute ‘clean’ and ‘libs’ and then transpile the .ts files
  4. ‘default’: will execute ‘build’, fire up the webserver and watch the .ts files for changes

Worth of mention is also the index.html which contains the SystemJs initialization code.


How to handle string localization with AngularJS and Typescript

As many of you may already know, most of the times we developers write something is because we feel the need to create. Not because the current project really requires it, but just because we feel the urge to write some code, patch something up. Especially when the project is reeeeally boring.

In my case I needed a quick and dirty way to localize strings in my AngularJS app. I know there are plenty of standard and non-standard ways to do this but this time I wanted a way to escape the boredom.

What I came up with is a simple Service that looks like this:

(yes, I’m using Typescript)

The implementation takes care of reading a very simple JSON file containing all the available cultures and the respective labels. Something like this:

The example app itself is very simple, there are just two controllers:

LanguageController acts as a simple wrapper over the ILanguageService, exposing the list of available cultures and allowing get/set for the current one. On the UI there’s just a dropdown with the cultures.

MainController instead takes care of requesting the labels from¬†ILanguageService and $watch-ing it’s currentCulture property. When an update is detected (eg. something changed on LanguageController), the new labels are fetched from the service.

Easy huh?

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