Migrating from AngularJS to Angular Using a “Hybrid” Approach

Hello, my dear readers! I am very happy today because I have prepared a very interesting article for you. So, if you have a few minutes, please don’t waste your time and let’s start reading. In this article I want to highlight the most important points. I reckon that after reading this article, everyone may think: „Surely, I want to practice it in my work”. Of course, I will reveal some general information with some details.

From my point of view, this topic is really worth your attention.

Table of Contents

A Hybrid Approach Using AngularJS and Angular

It seems to me that working with the most cutting-edge toolset is always an excellent opportunity to develop yourself as an expert and to dive into all the most advanced hip extracts which are just simple fun. As for me, I prefer to begin the projects from the scratch and to keep the setup that changes our preferences and project specifications. At this point, I want to deal with three important features:

To my mind, the process has to be incremental and you must work through the element after the component, service after service, and so on.
As for the application, it can’t stay frozen through the migration method as you need to give some new features.
One benefit remains the most important: no new comments would be improved using the legacy code.

The migration can be done collaboratively and developed over the time — it seems like a win-win situation. I want to say that the migration process is not all roses though. Of course, I’ll tell you about some of the experiences of the process and give a handful of working solutions that will help you to go through this. Surely, you’ll find it helpful when migrating your app from AngularJS to Angular.

Initial state: AngularJS 1.4

I want to start with AngularJS 1.4 that is written in TypeScript and Gulp as a task branch. And now, I want to present the following steps which can help you to start your work:

Moving to Webpack
Creating an Angular project, building and adding mandates
Preparing Webpack configuration for hybrid app
Bootstrapping the hybrid app
Hybrid app
UI Router

As usually, let’s discuss it in details.

Step 1: Moving to Webpack

As step one, I want to find a hopeful replacement for Gulp. On the top of that, there are two popular task posts out there —SystemJS and Webpack — and now let’s consider both of them. After some practice, presently I have ultimately decided to choose Webpack. The reasons behind my choice involved enough complexity and flexibility to run AngularJS 1.4 and then easily to handle the new Angular. It goes without saying that Webpack handles not only module bundling but can also prepare our application and run a dev server. As for the Webpack configuration, it often depends on your application’s specification, but you can find a lot of pre-made configurations on GitHub. Instead of diving into the comprehensive rundown of our complete form, I want to outline its most valuable components instead. Needless to say, Webpack configuration represents the entry property and includes two files: our AngularJS initialization file and the file that collects all global styles.

Step 2: Creating an Angular project structure and adding dependencies

Many people claim that setting up an Angular project without Angular CLI can be involved. It is often said that CLI tools are excellent and starting a new project with CLI takes only one command. But sometimes, I have to get my hands dirty and to start a project without the correct tools. Before setting up a new project structure, you can add Angular dependencies to our present project. Separating both frameworks allows us to keep the project’s structure clear. Elements that were rewritten to the new Angular can be easily separated from the old application, which helped us to keep the plan created. When you have installed all of the provinces and created the project structure, the next step is to add a minimum form for the Angular application.

Step 3: Preparing Webpack configuration for the hybrid app

When Webpack is launched and the Angular project is already built, it is time to configure Webpack in order to create the new project. Of course, to achieve that, you need two additional loaders: ts-loader and angular2-template-loader. As a result, the first one helps to load TypeScript files, the other provides us to load outside Angular template files.

Step 4: Bootstrapping the hybrid app

This step needs some additional configuration. AngularJS application has angular-deferred-bootstrap set up. This component gives a determining function before the app starts. It can be used to get the data from the backend, the arrangement, for example.

Step 6: Hybrid app

Once the hybrid app is up and running, you can start the method of the code upgrading. One of the most popular models for doing this is to use an Angular element in an AngularJS context. This can be a totally new element or one that was AngularJS earlier, but has been rewritten for Angular.

Step 7: UI Router

Downgrading or upgrading elements is not the only way to successful migration. I found out that the UI Router that was already there can help us with our task just as good. It can switch the logic between AngularJS and new Angular thanks to its care for hybrid apps. According to the experts’ opinion, the angular-hybrid module allows the UI Router to route to both AngularJS and Angular elements.

So, I represented you several steps of the initial state: AngularJS 1.4. It is quite clear that these steps make everything work easier. I hope that it is clear to you, what the main steps you may use.

Conclusion

So, let’s summarize all my words written above. I have tried to demonstrate the most important points, which can be helpful for you. I hope that this topic “Migrating from AngularJS to Angular using a ”hybrid” approach” helped you to get some more information about regression testing.

To conclude everything up, I’ll give you the list of 7 main steps for that.

Here is the list of them: