Adding a new segment or function to an existing web app isn’t always the simplest of tasks. Let’s say you have an online platform in dire need of customer support. You want to add an easily accessible chatbot.
Ripping apart all the existing code in order to implement this sounds like a nightmare. If your app also has the tendency to load all of its parts at once, a new feature will only slow it down.
Luckily for web developers across the globe, modularity once again comes to the rescue. Angular modules, in particular, let you add new features without breaking a sweat. If you’re interested in learning more about them — and how to use them in your projects — please, do read on.
What are Angular modules?
In today’s world of apps, most of them tend to consist of modules. In the case of the Angular framework, they are best defined as mechanisms to group code. Bundles, if you will. Said code can include components, directives, pipes, and services. When skilled developers combine such modules into a puzzle, they make up an app.
You can also observe Angular modules as classes. Within a class, it is possible to define public (API) or private methods (implementation details that remain hidden). The public-facing, exported elements are meant to interact with other modules. Private ones are for internal use only. In essence, modules are self-contained yet compatible with other modules.
All this relies on the NgModule to make it work. In Angular’s own modularity system, it’s considered the root module. It can be found under the name AppModule, conveniently stored in app.module.ts. There’s at least one in every app, while some have multiple. Regardless of the number, the hierarchy is such that one has to act as the main container. Others serve as “child modules”.
You can see the NgModule as a container for a cohesive block of code. It’s clearly defined and consists of metadata such as declarations, exports, imports, and providers. Its main purpose is to launch an app. You can do this by bootstrapping the module or performing a “Just in time” (JIT) compilation.
Other types of modules
Now that we’ve covered the main one, we also have to mention the other three types of Angular modules.
- Core module. Usually loaded globally. It contains elements used throughout the app. Examples include the navigation bar, footer, loader, etc.
- Feature module. It houses the most important features of your app. If you have an e-commerce app, your list of products, cart, chat supports, etc. will act as separate functionalities. Each of these is kept in a dedicated area or separate feature.
- Shared module. Contains reusable components, directives, and pipes. You can use them to write a custom grid or a filter.
Since we keep mentioning components, we might as well pause to explain what they are. A component is a fundamental building block of an application. It brings together HTML templates, CSS styles, and TypeScript logic. A component defines a specific part of the app’s functionality. In Angular, these can be buttons, forms, lists, tables, navigation menus, routing, modal windows, etc.
Don’t forget the libraries
Before moving on, we might also touch upon Angular libraries. They’re a great way of leveraging pre-built solutions. Their purpose is to enhance code organization in larger Angular ecosystems. Libraries enable code sharing, promote consistency, and simplify maintenance.
Things to look out for
So far, we have only discussed the positive sides of Angular modules. However, we should also look at some drawbacks an attentive developer should keep an eye on.
Initial setup. Modules require upfront planning and effort. Configuring the hierarchy can be time-consuming, especially if you plan on making your app scalable. Don’t rush it.
Complexity. A large number of disorganized modules can lead to severe difficulties in maintenance.
Module interdependeicnes. Reusing and sharing can create interdependencies. If your modules are too tightly coupled, it may become difficult to modify or extend your app.
Best practices to stick to
In order to avoid the above issues and make the most of Angular modules, there are some best practices you should consider. These design principles will give you a structured codebase and boost overall efficiency.
Keep modules focused on a single responsibility. They should encapsulate one feature. This keeps them truly modular, allowing for a more structured codebase.
Avoid overly granular modules. Don’t go in the opposite direction, creating separate bundles for the tiniest of tasks. Maintain a balanced approach.
Keep relationships between modules straightforward. The worst thing you can do is create circular dependencies. Remove one element and the entire app could come crashing down.
Stick to safe module naming conventions. Use the *Module suffix (e.g., UserModule, AuthenticationModule) in order to easily identify the purpose of each.
Take advantage of lazy loading. Don’t let your app load everything at once. Keep unnecessary parts dormant. Use modular structure to call on them when required. This can boost performance substantially.
Test, test, test. Create separate Angular modules for testing purposes.
Wrapping it all up
If you’re looking to fully master Angular modules, you’ll need to start by understanding the main types. Explore root, core, shared, and feature modules – and the roles they can play. Don’t forget to dip into different components and libraries.
Of course, some problems may arise but there are always best practices to help you solve them. Single responsibility, good naming conventions, lazy loading, and thorough testing are just some of the most sound.
Ultimately, Angular modules are an area of web development that’s well worth exploring. If you’re an ambitious developer-to-be, this new skill could boost your employability and give you the upper hand in the dynamic job market.