How to prepare for the migration AngularJS to Angular properly?

The fact that Google plans to get rid of AngularJS smoothly became known back in 2018. Exactly two years after the release of Angular 2. However, despite such news, many companies were still in no hurry to start the migration AngularJS to Angular. The death of Angular.js didn't seem like something critical to web project owners. Alternatively, they were worried the second version of Angular would meet the fate of the first one after a while. We can only guess about it.

Now, everyone who still maintains their web products built on a JavaScript-based framework has a hard time. They must either urgently begin the migration AngularJS to Angular, develop a new web product from scratch, or choose a suitable Angular.js alternative. If you've got here, chances are you've chosen the first option and want to know about how to prepare for this process. In today's blog post, our Angular development team will tell you everything you need to be aware of before starting the migration.

Choose your path first: The migration essentials

One of the first things to do before upgrading your legacy JavaScript-based project is to choose a migration method. The choice determines the whole further sequence of actions in prep for the migration AngularJS to Angular.

Which choices are open to you?

Think twice before you go on the attack. It's a crucial step, that may even affect the future of your business. You should consider all the risks before writing a plan to get ready for the platform upgrade.

When the hybrid method is used:

You have a large-scale web application with many features that takes many time to maintain;
You can't afford to disable web access for your customers suddenly, and you don't want to allow the web product to fail;
You don't have a huge development team, so you want to make the switch gradually and efficiently;
You've found a team of experts to help you get the job done.

Still, you should be prepared to spend a specific budget on the migration AngularJS to Angular and be ready for all sorts of difficulties. For example, you will have to perform many tests, fix bugs, and deal with problems like a dynamic compilation from the line.

Case in point: There were no problematic situations related to the upgrade of web projects in our practice. However, our ears have heard a story from a well-known online platform for learning English. Several years ago, the creators of the web service decided to improve it and move to a more recent version of Angular. The team took for dynamic compilation for Angular.js, which has the form:

const compiledContent = this.$compile(template)(scope);

this.$element.append(compiledContent);

Then they ran this piece through the JiT compiler. The problem was that even with AoT compilation, some of the dynamic templates were heavy. The page worked, but it took 6 seconds to compile. Moreover, for 3 of those seconds, nothing happened at all. The team had to try four solutions before they found the right one.

In which scenarios the parallel method is used:

You have a relatively small app, and it won't take you long to create a new Angular-based version;
You want to get a stable web project version out of the box and forget about Angular.js issues forever;
You don't need to maintain an existing web product 24/7, so you can focus the attention of your development team on building a new project.

Like the previous method, this model of the migration AngularJS to Angular also has its difficulties. For example, you have to go through the same stages of development again as with a JavaScript-based web product. You need to think through the architecture and logic of the web application, do numerous tests, clean up bugs, find better solutions to improve performance, etc. For some companies, it's not only expensive but an exhausting process.

Instructions on how to handle the hybrid migration model preparations

We don't know which option you're going to use for the migration AngularJS to Angular, so we've prepared two scenarios. Let's start with what you need to do to create a hybrid app.

Note: Depending on the specs of your product and industry, the actual number of steps will vary. Instructions to prepare for the upgrade may not be the same for all web projects. Contact us to schedule an evaluation of your web product and discuss our next steps.

A step-by-step preparation algorithm for the migration AngularJS to Angular

Note: The best way is to do a hybrid migration gradually. You'll have fewer crutches and thin-necks in the process by doing so. It's the official recommendation of the Angular coding team. You can jump several versions of the TypeScript-based front-end framework; however, you must be prepared for all sorts of complexities then.

Probably it is the most comprehensive plan of preparation for the migration AngularJS to Angular now. In rare cases, other instruments are added here, but the number of steps is generally equal to 4-5.

Tips on how to prepare for the migration AngularJS to Angular in parallel

Since there is no official guide for this upgrade model, it's pretty difficult to put together a step-by-step instruction as a cheat sheet. So, the TFC team shares a couple of tips on where to start preparing for the migration AngularJS to Angular.

Our pro tips

These are the main guidelines on how to prepare for the parallel migration AngularJS to Angular model. Well, there is plenty of routine work waiting for you even before starting the development. After all the hassle and expense, you will get a 100% working app without parts of legacy code. If you don't like Frankensteins, as hybrid apps are sometimes called, it's worth following this way of project development.

A brief conclusion on preparing for the migration of AngularJS to Angular

As you can see, you need preparation to properly migrate your web project from Angular 1 to one of the Angular 2+ versions. Only cohesive steps will help you achieve your goal, avoiding possible difficulties.

Lack of preparations leads to the following unwanted effects:

In the upcoming articles on the migration of AngularJS to Angular, we'll take a closer look at the choice of tools, step-by-step instructions for the hybrid transition model, and much more. A series of blog posts related to this topic can help you better understand the workflow steps and apply them to your project as needed. If you still have any questions about preparing for the upgrading, book a call with our Managing Partner or email info@thefrontendcompany.com.