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March 24, 2022
AngularJS to Angular

t seems The Frontend Company team has already discussed everything possible on the topic of AngularJS to Angular upgrade in our blog. However, there's still something we haven't mentioned before. These are the most common migration pitfalls. No matter how well you are prepared for Angular 2+ and how many projects you closed successfully, sometimes you have to face some challenges. Below, you'll learn 7 complexities you can encounter in the migration process.

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7 prevailing problems during AngularJS to Angular upgrade

The Frontend Company has encountered quite enough migration projects over the years. Since 2018, when Google announced the inclusion of LTS (Long Term Support) mode for AngularJS, we have regularly received requests to help with the switch. Over this period, there have been many cases with pitfalls that we want to tell you about. It's crucial to note that numerous teams face the same situations during the AngularJS to Angular upgrade. Our experience and experience of other programmers will surely come in handy.

Migration pitfall #1. Failure to create a hybrid app

The official guide from the Angular Team shows coders can easily do a hybrid migration scenario. With Google's crew guidelines, programmers can, in theory, perform the AngularJS to Angular upgrade without having to rewrite dependencies, services, and components manually.

In most cases, you can seamlessly build a hybrid web application and run two frameworks at once. For large-scale projects with a complex structure and multiple functions after building a hybrid, sometimes you still have to resort to a parallel migration scenario.

Pro-tip: If you want to evaluate possible difficulties beforehand, it's better to make a detailed migration plan.

Migration pitfall #2. Careful handling of downgradeModule

One of the best ways for the AngularJS to Angular upgrade is to use the ngUpgrade library. First, it's well suited for large and small web products. Second, the Angular team has released a detailed guide on how to work with it.

Programmers commonly use UpgradeModule for bootstrap when dealing with ngUpgrade. Sometimes coders leave this option behind and go for a helper function called downgradeModule. When using this option, you should remember to specify the UIRouter parameter in the source code. The app won't have to bootstrap states if the developer forgets about such a small thing.

Migration pitfall #3. No autocoding tools could be used

In some projects, devs can use template loaders and set up S2S (source-to-source) compilers. Typically, this is possible for small web apps or products where part of the back-end doesn't need to be reused in an upgraded system.

There are situations when to make the back-end work without failing; you have to redo part of the front-end. We had such a situation only once when the application back-end was based on ASP.NET. In that situation, we had to do the AngularJS to Angular upgrade by writing the front-end part of the source code.

Note: Methods for automating the migration process speed things up a bit. But in complex apps, it's better not to use them. If you suddenly encounter a bug at any stage, it won't be easy to find its cause quickly.

Migration pitfall #4. Problematic implementation of complex functionality

For improvements in technology when working with SaaS, you need to think about the roadmap in a way that makes enhancements and doesn't affect the interests of users. Many web applications are shared by thousands of people at the same time, both for studies or task management and for business. If the AngularJS to Angular upgrade team does something wrong, it will lower the quality of service and precede severe business losses.

The following requirements must be met to avoid pitfalls:

  • brainstorm and find several solutions to the issue;
  • make sure that the deadline for the migration is not burning;
  • find a team of specialists who have done similar projects.

There is no one-size-fits-all solution in situations where you need to implement complex functionality. You will have to think of a new way to enhance each time, focusing on the starting architecture and user needs. The task of the programming team in such a circumstance becomes additional work on dependencies and preserving the business logic of the web app.

Migration pitfall #5. Not all tool kits are equally effective

It is another common trap that hinders many in the AngularJS to Angular upgrade process. The tools list is just a tip for companies and devs planning to migrate. There is no single toolkit capable of handling different types of challenges. So, it's vital for teams, on the one hand, to have a cheat sheet with a set of valuable tools. On the other hand, they are not always relevant to current projects.

Typically, this happens with instruments for outdated AngularJS versions or the latest Angular ones. Not all tools will have any good compatibility; therefore, during migration, one has to look for equivalents and urgently adjust the selection of solutions. The same goes for libraries. Abandoned or obsolete libraries create bottlenecks to the code, not contributing to its successful switch.

Migration pitfall #6. Lack of preparation and $scope

Angular 2+ is missing the $scope object, so it's critical to get rid of it for a successful AngularJS to Angular upgrade. Although this step seems obvious and simple to many people, experts do not always keep it in mind at the preparation stage.

What is the danger of such a pitfall? Loss of time. If the coders missed $scope in the source code, they need to go back a few steps and run migration preparations harder. Such a situation has a solution, but it's better not waste extra hours on nuances like this.

Migration pitfall #7. No customization and no consideration of the multitenancy

For web services and structurally complex applications, the headache of AngularJS to Angular upgrade is multitenancy. In some projects, the development team needs to provide customizations specifically for each client's needs.

Customizing settings for each person while keeping the service highly adaptable and ensuring that some functions can be added on demand isn't accessible. You can manually specify specific patterns, but it's tough to find a solution and keep the interface the same regardless of personalization.

If you solve the issue wrong, the web application interface will flop, and the business logic won't be preserved. Transferring the source code from one framework to another is not 100% successful for these cases.

In this article, we have moved away from particular pitfalls cases in the AngularJS to Angular upgrade. Here we have summarized only the most common issues. Do you want to avoid such situations and make a problem-free Angular 1 migration? The Frontend Company team is ready to help you. If you have questions or need advice about your project, contact or chat online at the The Frontend Company website to get more details.

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