Angular

You Don't Need NgRx To Write a Good Angular App

Published Sep 1, 2023

Updated Sep 1, 2023

4 min read

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

NgRx is a great tool that allows you to manage state and side effects in Angular applications in a Redux-like manner. It streamlines state changes with its unidirectional data flow, and offers a structured approach to handling data and side effects. Numerous posts on our blog detail its strengths and affiliated techniques. Some Angular developers even argue that incorporating NgRx is imperative once an app expands beyond two features.

While NgRx can undoubtedly enhance an Angular application or library by simplifying debugging, translating business logic into code, and improving the architecture, it does present a steep learning curve. Despite the provocative title, there is some truth to the statement: your app or library may indeed not need NgRx. Surprisingly, I successfully developed a suite of enterprise Angular libraries over five years without involving NgRx.

In that project, we decided to opt out of using a state management library like NgRx because of its steep learning curve. Developers with varying levels of Angular expertise were involved, and the goal was to simplify their experience. My bold assertion is that, with careful consideration of architectural patterns, it is entirely possible to develop a robust app or library using only Angular, without any third-party libraries. Employing select design patterns and leveraging Angular's built-in tools can yield a highly maintainable app, even without a dedicated state management library.

Having shared my somewhat audacious opinion, let me now support it by outlining a few patterns that facilitate the development of a maintainable, stateful Angular application or library without NgRx.

Services and the Singleton Pattern

Services provided in root or a module yield a shared instance across the entire app or module, effectively rendering them singletons. This characteristic makes them ideal for managing and sharing state across components without requiring a dedicated state management tool like NgRx. Particularly, for small to medium-sized applications, a "state service" can be a straightforward and effective alternative to a comprehensive state management solution when implemented correctly.

To accurately implement state in a singleton service, consider the following:

Restrict state data to private properties and expose them only through public methods or observables to prevent external mutations. Such a pattern safeguards the integrity of your state by averting unauthorized modifications.
Utilize BehaviorSubjects or signals to enable components to respond to state changes. Both BehaviorSubject and SettableSignal retain the current value and emit it to new subscribers immediately. Components can then subscribe to these to receive the current value and any subsequent updates.
Expose public methods in your service that manage state modifications to centralize the logic for updating the state and incorporate validation, logging, or other necessary side effects.
When modifying state, always return a new instance of the data rather than altering the original data. This ensures that references are broken and components that rely on change detection can accurately detect changes.

Good Component Architecture

Distinguish your UI components into stateful (containers) and stateless (presentational) components. Stateful components manage data and logic, while stateless components merely receive data via inputs and emit events without maintaining an internal state.

Do not get dragged into the rabbit hole of anti-patterns such as input drilling or event bubbling while trying to make as many components presentational as possible. Instead, use a Data Service Layer to provide a clean abstraction over backend API calls and handle error management, data transformation, caching, and even state management where it makes sense. Although injecting a service into a component technically categorizes it as a "smart" component, segregating the data access logic into a separate service layer ultimately enhances modularity, maintainability, scalability, and testability.

Immutability

A best practice is to always treat your state as immutable. Instead of modifying an object or an array directly, you should create a new copy with the changes. Adhering to immutability ensures predictability and can help in tracking changes.

Applying the ChangeDetectionStrategy.OnPush strategy to components whenever possible is also a good idea as it not only optimizes performance since Angular only evaluates the component for changes when its inputs change or when a bound event is triggered, but it also enforces immutability. Change detection is only activated when a different object instance is passed to the input.

Leveraging Angular Router

Angular's router is a powerful tool for managing application state. It enables navigation between different parts of an application, allowing parameters to be passed along, effectively using the URL as a single source of truth for your application state, which makes the application more predictable, bookmarkable, and capable of maintaining state across reloads. Moreover, components can subscribe to URL changes and react accordingly. You can also employ router resolvers to fetch data before navigating to a route, ensuring that the necessary state is loaded before the route is activated. However, think carefully about what state you store in the URL; it should ideally only contain the state essential for navigating to a specific view of your application. More ephemeral states, like UI state, should be managed in components or services.

Conclusion

Angular provides lots of built-in tools and features you can effectively leverage to develop robust, maintainable applications without third-party state management libraries like NgRx. While NgRx is undoubtedly a valuable tool for managing state and side effects in large, complex applications, it may not be necessary for all projects. By employing thoughtful design patterns, such as the Singleton Pattern, adhering to principles of immutability, and leveraging Angular's built-in tools like the Router and Services, you can build a highly maintainable and stateful Angular application or library.

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About the author(s)

Jan Kaiser
Software engineer passionate about everything web-related. Particularly loves Angular, SCSS, TypeScript, soccer and dachshunds
@honzikec @honzikec

Overview of the New Signal APIs in Angular

Overview of the New Signal APIs in Angular Google's Minko Gechev and Jeremy Elbourn announced many exciting things at NG Conf 2024. Among them is the addition of several new signal-based APIs. They are already in developer preview, so we can play around with them. Let's dig into it, starting with signal-based inputs and the new matching outputs API. Signal Based Inputs Discussions about signal-based inputs have been taking place in the Angular community for some time now, and they are finally here. Until now, you used the @Input() decorator to define inputs. This is what you'd have to write in your component to declare an optional and a required input: ` With the new signal-based inputs, you can write much less boilerplate code. Here is how you can define the same inputs using the new syntax: ` It's not only less boilerplate, but because the values are signals, you can also use them directly in computed signals and effects. That, effectively, means you get to avoid computing combined values in ngOnChanges or using setters for your inputs to be able to compute derived values. In addition, input signals are read-only. The New Output I intentionally avoid calling them signal-based outputs because they are not. They still work the same way as the old outputs. The Angular team has just introduced a new output API that is more consistent with the latest inputs API and allows you to write less boilerplate, similar to the new input API. Here is how you would define an output until now: ` Here is how you can define the same output using the new syntax: ` The thing I like about the new output API is that sometimes it happens to me that I forget to instantiate the EventEmitter because I do this instead: ` You won't forget to instantiate the output with the new syntax because the output function does it for you. Signal Queries I am sure most readers know the @ViewChild, @ViewChildren, @ContentChild, and @ContentChildren decorators very well and have experienced the pain of triggering the infamous ExpressionChangedAfterItHasBeenCheckedError or having the values unavailable when needed. Here is a refresher on how you would use these decorators until now: ` With the new signal queries, similar to the new input API, the values are signals, and you can use them directly in computed signals and effects. You can define the same queries using the new syntax: ` Jeremy Elbourn mentioned that the new signal queries have better type inference and are more consistent with the new input and output APIs. He also showcased a brand new feature not available with the old queries. You can now define a query as required, and the Angular compiler will throw an error if the query has no result, guaranteeing that the value won't be undefined. Here is how you can define a required query: ` Model Inputs Jeremy and Minko announced the last new feature is the model inputs. The name is vague, but the feature is cool—it simplifies the definition of two-way bindings. Until now, to achieve two-way binding, you would have to define an input and an output following a given naming convention. @Input and @Output had to be defined with the same name (followed by "Change" in the case of the output). Then, you could use the template's [()] syntax. ` ` That way, you could keep the value in sync between the parent and the child component. With the new model inputs, you can define a two-way binding with a single line of code. Here is how you can define the same two-way binding using the new syntax: ` The html template stays the same: ` The model function returns a writable signal that can be updated directly. The value will be propagated back to any two-way bindings. Conclusion The new signal-based APIs are a great addition to Angular. They allow you to write less boilerplate code and make your components more reactive. The new APIs are already in developer preview, so you can start playing around with them today. I look forward to seeing how the community will adopt these new features and what other exciting things the Angular team has in store for us, such as zoneless apps by default....

Apr 3, 2024

3 mins

AngularJavaScript

Using HttpClient in Modern Angular Applications

Introduction With all the wonderful treats that the Angular team has given us during the recent "renaissance" era, many new developers are joining in on the fun. And one of the challenges they'll face at some point is how to call an API from your Angular application properly. Unfortunately, while searching for a guide on how to do this, they might stumble upon a lot of outdated information. Hence, this article should serve as a reliable guide on how to use the HttpClient in Angular >= 17. The Setup To make an HTTP request in Angular, you can take advantage of the HttpClient provided by the @angular/common/http package. To use it, you'll need to provide it. Here's how you can do that for the whole application using the bootstrapApplication function from @angular/platform-browser: ` With that, you should be good to go. You can now inject the HttpClient into any service or component in your application. Using HttpClient in Services Let's take a common example: You have a database object, say a Movie, and you want to implement CRUD operations on it. Typically, you'll want to create a service that provides methods for these operations. Let's call this service MovieService and create a skeleton for it with a method for getting all movies. ` Implementing the Method using HttpClient Let's assume we have a GraphQL API for our movies. We can implement our getAllMovies using HttpClient to make a request to fetch all movies. First, we will need to define a new type to represent the response from the API. This is especially important when you are using GraphQL, which may return a specific structure, such as: ` When working with a real API, you'll likely use some code generator to generate the types for the response from the GraphQL schema. But for the sake of this example, we'll create an interface to represent the response manually: ` Now, we can implement the getAllMovies method using HttpClient: ` > Note: The post method is used here because we are sending a request body. If you are making a GET request (e.g. to a REST API), you can use the get method instead. The getAllMovies method returns an Observable of MoviesListResponse. In this example, I have typed it explicitly to make it obvious at first glance, but you could also omit the type annotation, and TypeScript should infer it. > Note: While I'm excited about signals as much as the next guy, making HTTP requests is one of the typical async operations for which RxJS Observables are a perfect fit, making a great argument for RxJS still having a solid place in Angular alongside signals. Using the Service in a Component Now that we have our MovieService set up, we can use it as a component to fetch and display all movies. But first, let's create a Movie interface to represent the structure of a movie. Trust me, this will prevent many potential headaches down the line. Although using any at the beginning and implementing the types later is a valid approach in some cases, using data fetched from an API without validating the type will inevitably lead to bugs that are difficult to solve. ` Now, we can start implementing our standalone MoviesComponent: ` In this component, we are calling the getAllMovies method from the MovieService in the constructor to fetch all movies and assign them to the movies property which we will use to display the movies in the template. ` In this case, placing our code inside the constructor is safe because it doesn’t depend on any @Input(). If it were, our code would fail because the inputs aren’t initialized at time of instantiation. That's why it is sometimes recommended to place logic in ngOnInit instead. You could also put this call in an arbitrary method that is called e.g. on a button click. Another way to handle the subscription is to use the async pipe in the template. This way, Angular will automatically subscribe and unsubscribe from the observable for you and you won't have to assign the response to a property in the component. Due to the structure of the returned data, however, we'll need to use the RxJS map operator to extract the movies from the response. ` > Note using the pipe method to chain the map operator to the observable returned by getAllMovies. This is a common pattern when working with RxJS observables introduced in RxJs 5.5. If you see code that uses the map operator directly on the observable and wonder why it isn't working for you, it's likely using an older version of RxJS. Now, we can simply apply the async pipe in the template to subscribe to the observable and display the movies: ` Conclusion HttpClient in Angular is pretty straightforward, but with all the changes to RxJS and Angular in the past few years, it can pose a significant challenge if you're not super-experienced with those technologies and stumble upon outdated resources. Following this article, you should hopefully be able to implement your service using HttpClient to make requests to an API in your modern Angular application and avoid the struggle of copying outdated code snippets....

Mar 27, 2024

4 mins

AngularJavaScript

Vercel & React Native - A New Era of Mobile Development?

Vercel & React Native - A New Era of Mobile Development? Jared Palmer of Vercel recently announced an acquisition that spiked our interest. Having worked extensively with both Next.js and Vercel, as well as React Native, we were curious to see what the appointment of Fernando Rojo, the creator of Solito, as Vercel's Head of Mobile, would mean for the future of React Native and Vercel. While we can only speculate on what the future holds, we can look closer at Solito and its current integration with Vercel. Based on the information available, we can also make some educated guesses about what the future might hold for React Native and Vercel. What is Solito? Based on a recent tweet by Guillermo Rauch, one might assume that Solito allows you to build mobile apps with Next.js. While that might become a reality in the future, Jamon Holmgren, the CTO of Infinite Red, added some context to the conversation. According to Jamon, Solito is a cross-platform framework built on top of two existing technologies: - For the web, Solito leverages Next.js. - For mobile, Solito takes advantage of Expo. That means that, at the moment, you can't build mobile apps using Next.js & Solito only - you still need Expo and React Native. Even Jamon, however, admits that even the current integration of Solito with Vercel is exciting. Let's take a closer look at what Solito is according to its official website: > This library is two things: > > 1. A tiny wrapper around React Navigation and Next.js that lets you share navigation code across platforms. > > 2. A set of patterns and examples for building cross-platform apps with React Native + Next.js. We can see that Jamon was right - Solito allows you to share navigation code between Next.js and React Native and provides some patterns and components that you can use to build cross-platform apps, but it doesn't replace React Native or Expo. The Cross-Platformness of Solito So, we know Solito provides a way to share navigation and some patterns between Next.js and React Native. But what precisely does that entail? Cross-Platform Hooks and Components If you look at Solito's documentation, you'll see that it's not only navigation you can share between Next.js and React Native. There are a few components that wrap Next.js components and make them available in React Native: - Link - a component that wraps Next.js' Link component and allows you to navigate between screens in React Native. - TextLink - a component that also wraps Next.js' Link component but accepts text nodes as children. - MotiLink - a component that wraps Next.js' Link component and allows you to animate the link using moti, a popular animation library for React Native. - SolitoImage - a component that wraps Next.js' Image component and allows you to display images in React Native. On top of that, Solito provides a few hooks that you can use for shared routing and navigation: - useRouter() - a hook that lets you navigate between screens across platforms using URLs and Next.js Url objects. - useLink() - a hook that lets you create Link components across the two platforms. - createParam() - a function that returns the useParam() and useParams() hooks which allow you to access and update URL parameters across platforms. Shared Logic The Solito starter project is structured as a monorepo containing: - apps/next - the Next.js application. - apps/expo or apps/native - the React Native application. - packages/app - shared packages across the two applications: - features - providers - navigation The shared packages contain the shared logic and components you can use across the two platforms. For example, the features package contains the shared components organized by feature, the providers package contains the shared context providers, and the navigation package includes the shared navigation logic. One of the key principles of Solito is gradual adoption, meaning that if you use Solito and follow the recommended structure and patterns, you can start with a Next.js application only and eventually add a React Native application to the mix. Deployments Deploying the Next.js application built on Solito is as easy as deploying any other Next.js application. You can deploy it to Vercel like any other Next.js application, e.g., by linking your GitHub repository to Vercel and setting up automatic deployments. Deploying the React Native application built on top of Solito to Expo is a little bit more involved - you cannot directly use the Github Action recommended by Expo without some modification as Solito uses a monorepo structure. The adjustment, however, is luckily just a one-liner. You just need to add the working-directory parameter to the eas update --auto command in the Github Action. Here's what the modified part of the Expo Github Action would look like: ` What Does the Future Hold? While we can't predict the future, we can make some educated guesses about what the future might hold for Solito, React Native, Expo, and Vercel, given what we know about the current state of Solito and the recent acquisition of Fernando Rojo by Vercel. A Competitor to Expo? One question that comes to mind is whether Vercel will work towards creating a competitor to Expo. While it's too early to tell, it's not entirely out of the question. Vercel has been expanding its offering beyond Next.js and static sites, and it's not hard to imagine that it might want to provide a more integrated, frictionless solution for building mobile apps, further bridging the gap between web and mobile development. However, Expo is a mature and well-established platform, and building a mobile app toolchain from scratch is no trivial task. It would be easier for Vercel to build on top of Expo and partner with them to provide a more integrated solution for building mobile apps with Next.js. Furthermore, we need to consider Vercel's target audience. Most of Vercel's customers are focused on web development with Next.js, and switching to a mobile-first approach might not be in their best interest. That being said, Vercel has been expanding its offering to cater to a broader audience, and providing a more integrated solution for building mobile apps might be a step in that direction. A Cross-Platform Framework for Mobile Apps with Next.js? Imagine a future where you write your entire application in Next.js — using its routing, file structure, and dev tools — and still produce native mobile apps for iOS and Android. It's unlikely such functionality would be built from scratch. It would likely still rely on React Native + Expo to handle the actual native modules, build processes, and distribution. From the developer’s point of view, however, it would still feel like writing Next.js. While this idea sounds exciting, it's not likely to happen in the near future. Building a cross-platform framework that allows you to build mobile apps with Next.js only would require a lot of work and coordination between Vercel, Expo, and the React Native community. Furthermore, there are some conceptual differences between Next.js and React Native that would need to be addressed, such as Next.js being primarily SSR-oriented and native mobile apps running on the client. Vercel Building on Top of Solito? One of the more likely scenarios is that Vercel will build on top of Solito to provide a more integrated solution for building mobile apps with Next.js. This could involve providing more components, hooks, and patterns for building cross-platform apps, as well as improving the deployment process for React Native applications built on top of Solito. A potential partnership between Vercel and Expo, or at least some kind of closer integration, could also be in the cards in this scenario. While Expo already provides a robust infrastructure for building mobile apps, Vercel could provide complementary services or features that make it easier to build mobile apps on top of Solito. Conclusion Some news regarding Vercel and mobile development is very likely on the horizon. After all, Guillermo Rauch, the CEO of Vercel, has himself stated that Vercel will keep raising the quality bar of the mobile and web ecosystems. While it's unlikely we'll see a full-fledged mobile app framework built on top of Next.js or a direct competitor to Expo in the near future, it's not hard to imagine that Vercel will provide more tools and services for building mobile apps with Next.js. Solito is a step in that direction, and it's exciting to see what the future holds for mobile development with Vercel....

Apr 4, 2025

6 mins

NextJSReact NativeDevOps

The simplicity of deploying an MCP server on Vercel

The current Model Context Protocol (MCP) spec is shifting developers toward lightweight, stateless servers that serve as tool providers for LLM agents. These MCP servers communicate over HTTP, with OAuth handled clientside. Vercel’s infrastructure makes it easy to iterate quickly and ship agentic AI tools without overhead. Example of Lightweight MCP Server Design At This Dot Labs, we built an MCP server that leverages the DocuSign Navigator API. The tools, like `get_agreements`, make a request to the DocuSign API to fetch data and then respond in an LLM-friendly way. ` Before the MCP can request anything, it needs to guide the client on how to kick off OAuth. This involves providing some MCP spec metadata API endpoints that include necessary information about where to obtain authorization tokens and what resources it can access. By understanding these details, the client can seamlessly initiate the OAuth process, ensuring secure and efficient data access. The Oauth flow begins when the user's LLM client makes a request without a valid auth token. In this case they’ll get a 401 response from our server with a WWW-Authenticate header, and then the client will leverage the metadata we exposed to discover the authorization server. Next, the OAuth flow kicks off directly with Docusign as directed by the metadata. Once the client has the token, it passes it in the Authorization header for tool requests to the API. ` This minimal set of API routes enables me to fetch Docusign Navigator data using natural language in my agent chat interface. Deployment Options I deployed this MCP server two different ways: as a Fastify backend and then by Vercel functions. Seeing how simple my Fastify MCP server was, and not really having a plan for deployment yet, I was eager to rewrite it for Vercel. The case for Vercel: * My own familiarity with Next.js API deployment * Fit for architecture * The extremely simple deployment process * Deploy previews (the eternal Vercel customer conversion feature, IMO) Previews of unfamiliar territory Did you know that the MCP spec doesn’t “just work” for use as ChatGPT tooling? Neither did I, and I had to experiment to prove out requirements that I was unfamiliar with. Part of moving fast for me was just deploying Vercel previews right out of the CLI so I could test my API as a Connector in ChatGPT. This was a great workflow for me, and invaluable for the team in code review. Stuff I’m Not Worried About Vercel’s mcp-handler package made setup effortless by abstracting away some of the complexity of implementing the MCP server. It gives you a drop-in way to define tools, setup https-streaming, and handle Oauth. By building on Vercel’s ecosystem, I can focus entirely on shipping my product without worrying about deployment, scaling, or server management. Everything just works. ` A Brief Case for MCP on Next.js Building an API without Next.js on Vercel is straightforward. Though, I’d be happy deploying this as a Next.js app, with the frontend features serving as the documentation, or the tools being a part of your website's agentic capabilities. Overall, this lowers the barrier to building any MCP you want for yourself, and I think that’s cool. Conclusion I'll avoid quoting Vercel documentation in this post. AI tooling is a critical component of this natural language UI, and we just want to ship. I declare Vercel is excellent for stateless MCP servers served over http....

Aug 13, 2025

3 mins

VercelMCP

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