Angular

What's New in @this-dot@route-config v1.2

Published Nov 2, 2021

Updated Feb 13, 2023

2 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This article was written over 18 months ago and may contain information that is out of date.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.

Recently, we introduced our first open source library to have easier access to RouterModule config's data property. If you haven't read about it yet, I recommend reading my colleague’s introductory blog post.

Since the first release, we received great feedback from the community, and we've been working on improving the developer experience using it. In this article, I'd like to share with you the new features we've introduced, and how to use them.

RouteDataDirective (`*tdRouteData`)

One of the new features we've introduced is a directive for directly accessing the current route data property from within the component's template. This is a structural directive that binds the whole data property to the local variable we define. To use it, we need to add a *tdRouteData directive attribute to a tag that we want in order to use some route's defined properties.

<div *tdRouteData="let routeData">
  <h1>{{ routeData.pageTitle }}</h1>
</div>

In the routeData, we have access to the whole data property (along with all the properties from the data properties defined in parent routes).

Given the following router configuration, we will display the correct title depending on the subpage we're currently on.

@NgModule({
  imports: [
    RouterModule.forChild([
      {
        path: '',
        component: Example1Component,
        children: [
          {
            path: 'first',
            component: FirstComponent,
            data: {
              title: ['First component'],
            },
          },
          {
            path: 'second',
            component: SecondComponent,
            data: {
              title: ['Second component'],
            },
          },
          {
            path: '**',
            pathMatch: 'full',
            redirectTo: 'first',
          },
        ],
      },
    ]),
  ],
})
export class Example1Module {}

If you need to use multiple route properties within one component's template, it is recommended to only use *tdRouteData on one root tag (or ng-container in case your template doesn't have one top-level element). This way we only create one subscription to route's data per template.

<ng-container *tdRouteData="let routeData">
  <h1>{{ routeData.pageTitle }}</h1>
  <ul *ngFor="let item of routeData.someRouteItems">
    <li>{{ item }}</li>
  </ul>
</ng-container>

RouteDataHasDirective (`*tdRouteDataHas`)

The second new feature we've introduced is a directive similar to *tdRouteTags directive we've already shown in the previous article. The big difference is more configuration options. The new *tdRouteDataHas directive allows the developer to configure the property that this directive is using to determine which template to show. We can configure this via the tdRouteDataHasPropName input (or just propName using shorthand syntax). Let's see it in action.

<p *tdRouteDataHas="'showParagraphTag'; propName: 'customRouteTagsProp';">
  Go to first
</p>

Given the following router configuration, we will display the paragraph only on the first route, and not on the second route.

RouterModule.forChild([
  {
    path: '',
    component: Example2Component,
    children: [
      {
        path: 'first',
        component: FirstComponent,
        data: {
          customRouteTagsProp: ['showParagraphTag'],
        },
      },
      {
        path: 'second',
        component: SecondComponent,
        data: {
          customRouteTagsProp: [],
        },
      },
      {
        path: '**',
        pathMatch: 'full',
        redirectTo: 'first',
      },
    ],
  },
]);

Summary

This concludes the new features we've added since the first release. I would like to thank all the people that provided us with suggestions for those features! We're constantly looking for ways to improve our libraries, and encourage you to let us know about any questions or feature requests via an issue on our repository.

If you want to play with the new features, please have a go at this Stackblitz example.

In case you have any questions, you can always tweet or DM me at @ktrz. I'm always happy to help!

This Dot is a consultancy dedicated to guiding companies through their modernization and digital transformation journeys. Specializing in replatforming, modernizing, and launching new initiatives, we stand out by taking true ownership of your engineering projects.

We love helping teams with projects that have missed their deadlines or helping keep your strategic digital initiatives on course. Check out our case studies and our clients that trust us with their engineering.

Chris Trześniewski

Software Engineer, ultra-marathoner. He is passionate about functional programming in JavaScript and loves working with RxJS. In his free time he likes to go jogging.

@ktrz__@ktrz

Exploring Angular Forms: A New Alternative with Signals

Exploring Angular Forms: A New Alternative with Signals In the world of Angular, forms are essential for user interaction, whether you're crafting a simple login page or a more complex user profile interface. Angular traditionally offers two primary approaches: template-driven forms and reactive forms. In my previous series on Angular Reactive Forms, I explored how to harness reactive forms' power to manage complex logic, create dynamic forms, and build custom form controls. A new tool for managing reactivity - signals - has been introduced in version 16 of Angular and has been the focus of Angular maintainers ever since, becoming stable with version 17. Signals allow you to handle state changes declaratively, offering an exciting alternative that combines the simplicity of template-driven forms with the robust reactivity of reactive forms. This article will examine how signals can add reactivity to both simple and complex forms in Angular. Recap: Angular Forms Approaches Before diving into the topic of enhancing template-driven forms with signals, let’s quickly recap Angular's traditional forms approaches: 1. Template-Driven Forms: Defined directly in the HTML template using directives like ngModel, these forms are easy to set up and are ideal for simple forms. However, they may not provide the fine-grained control required for more complex scenarios. Here's a minimal example of a template-driven form: ` ` 2. Reactive Forms: Managed programmatically in the component class using Angular's FormGroup, FormControl, and FormArray classes; reactive forms offer granular control over form state and validation. This approach is well-suited for complex forms, as my previous articles on Angular Reactive Forms discussed. And here's a minimal example of a reactive form: ` ` Introducing Signals as a New Way to Handle Form Reactivity With the release of Angular 16, signals have emerged as a new way to manage reactivity. Signals provide a declarative approach to state management, making your code more predictable and easier to understand. When applied to forms, signals can enhance the simplicity of template-driven forms while offering the reactivity and control typically associated with reactive forms. Let’s explore how signals can be used in both simple and complex form scenarios. Example 1: A Simple Template-Driven Form with Signals Consider a basic login form. Typically, this would be implemented using template-driven forms like this: ` ` This approach works well for simple forms, but by introducing signals, we can keep the simplicity while adding reactive capabilities: ` ` In this example, the form fields are defined as signals, allowing for reactive updates whenever the form state changes. The formValue signal provides a computed value that reflects the current state of the form. This approach offers a more declarative way to manage form state and reactivity, combining the simplicity of template-driven forms with the power of signals. You may be tempted to define the form directly as an object inside a signal. While such an approach may seem more concise, typing into the individual fields does not dispatch reactivity updates, which is usually a deal breaker. Here’s an example StackBlitz with a component suffering from such an issue: Therefore, if you'd like to react to changes in the form fields, it's better to define each field as a separate signal. By defining each form field as a separate signal, you ensure that changes to individual fields trigger reactivity updates correctly. Example 2: A Complex Form with Signals You may see little benefit in using signals for simple forms like the login form above, but they truly shine when handling more complex forms. Let's explore a more intricate scenario - a user profile form that includes fields like firstName, lastName, email, phoneNumbers, and address. The phoneNumbers field is dynamic, allowing users to add or remove phone numbers as needed. Here's how this form might be defined using signals: ` > Notice that the phoneNumbers field is defined as a signal of an array of signals. This structure allows us to track changes to individual phone numbers and update the form state reactively. The addPhoneNumber and removePhoneNumber methods update the phoneNumbers signal array, triggering reactivity updates in the form. ` > In the template, we use the phoneNumbers signal array to dynamically render the phone number input fields. The addPhoneNumber and removePhoneNumber methods allow users to reactively add or remove phone numbers, updating the form state. Notice the usage of the track function, which is necessary to ensure that the ngFor directive tracks changes to the phoneNumbers array correctly. Here's a StackBlitz demo of the complex form example for you to play around with: Validating Forms with Signals Validation is critical to any form, ensuring that user input meets the required criteria before submission. With signals, validation can be handled in a reactive and declarative manner. In the complex form example above, we've implemented a computed signal called formValid, which checks whether all fields meet specific validation criteria. The validation logic can easily be customized to accommodate different rules, such as checking for valid email formats or ensuring that all required fields are filled out. Using signals for validation allows you to create more maintainable and testable code, as the validation rules are clearly defined and react automatically to changes in form fields. It can even be abstracted into a separate utility to make it reusable across different forms. In the complex form example, the formValid signal ensures that all required fields are filled and validates the email and phone numbers format. This approach to validation is a bit simple and needs to be better connected to the actual form fields. While it will work for many use cases, in some cases, you might want to wait until explicit "signal forms" support is added to Angular. Tim Deschryver started implementing some abstractions around signal forms, including validation and wrote an article about it. Let's see if something like this will be added to Angular in the future. Why Use Signals in Angular Forms? The adoption of signals in Angular provides a powerful new way to manage form state and reactivity. Signals offer a flexible, declarative approach that can simplify complex form handling by combining the strengths of template-driven forms and reactive forms. Here are some key benefits of using signals in Angular forms: 1. Declarative State Management: Signals allow you to define form fields and computed values declaratively, making your code more predictable and easier to understand. 2. Reactivity: Signals provide reactive updates to form fields, ensuring that changes to the form state trigger reactivity updates automatically. 3. Granular Control: Signals allow you to define form fields at a granular level, enabling fine-grained control over form state and validation. 4. Dynamic Forms: Signals can be used to create dynamic forms with fields that can be added or removed dynamically, providing a flexible way to handle complex form scenarios. 5. Simplicity: Signals can offer a simpler, more concise way to manage form states than traditional reactive forms, making building and maintaining complex forms easier. Conclusion In my previous articles, we explored the powerful features of Angular reactive forms, from dynamic form construction to custom form controls. With the introduction of signals, Angular developers have a new tool that merges the simplicity of template-driven forms with the reactivity of reactive forms. While many use cases warrant Reactive Forms, signals provide a fresh, powerful alternative for managing form state in Angular applications requiring a more straightforward, declarative approach. As Angular continues to evolve, experimenting with these new features will help you build more maintainable, performant applications. Happy coding!...

Oct 4, 2024

5 mins

AngularJavaScript

SSR Finally a First-Class Citizen in Angular?

I am sure you've already heard about server-side rendering (SSR). Generally, it's a technique used to deliver the HTML content generated by the server to the client. The client-side JavaScript framework then hydrates that HTML content to provide a fully interactive application. SSR provides numerous benefits if used correctly, including improved initial load times, better content indexing by search engines, and improved performance on lower-tier devices. Driven by the need for faster, more efficient web applications, with the rise in popularity of Node.js and, thus, server-side JavaScript, SSR has become a de facto standard in modern web development frameworks. At first, SSR was being provided as a part of meta-frameworks like Next.js, Nuxt, or Analog.js. Then, React introduced React Server Components, which marked a significant milestone in the way we think about front-end development. We think of front-end frameworks as being effectively full-stack, and a purely SPA approach is falling out of favor. However, I'm willing to bet that if you're a developer focused mostly on Angular, you may not have heard as much about SSR as your React counterparts. For a long time, Angular has been mostly focused on the SPA approach, and while we had Angular Universal or Analog.js, it was not as widely adopted. And that makes sense, given that Angular was widely regarded as best suited for complex, interactive applications, such as SaaS products or internal company tools, where SEO and initial load times were not as critical as they are for consumer-facing applications. Nevertheless, we have been blessed with the so-called Angular Renaissance, which has, among other things, brought SSR to the forefront of Angular development with the @angular/ssr package. Let's look at what Angular SSR is, how it works, and how you can get started. @angular/ssr The @angular/ssr package is not new; it was written from scratch. It's still Angular Universal. However, it's been pulled into the Angular CLI repository, and the appropriate schematics have been added to make it easier to use. What that means is that you can now add SSR to your Angular application with a single command: ` and you can generate a new SSR application with: ` And to make SSR a first-class citizen, the Angular team is planning to make it the default in the next version. But surely, it's not only rebranding and some CLI commands, you may say. And you're right. You may remember that hydration in Angular Universal has not been optimal as it was destructive and required essentially a complete re-render of the application, thus pretty much negating the benefits of SSR. With the introduction of non-destructive hydration in Angular 16 and its stability in Angular 17, the Angular team has taken a significant step forward in making SSR a first-class citizen. How to Make an SSR-capable Angular Application Let's look at how to use Angular SSR in practice by creating a simple SSR app. First, we need to create a new Angular application with SSR support: ` That will generate a few server-specific files: - server.ts, which is an Express server configured to handle Angular SSR requests by default but can also be extended to handle API routes, or anything else that Express can handle. - src/app/app.config.server.ts provides configuration for the server application similar to your app.config.ts, which defines the configuration for your client application. Both export an instance of ApplicationConfig - src/main.server.ts bootstraps the server application in a similar way to what main.ts does for your client app by calling the bootstrapApplication function. You should have an SSR application ready just like that. You can verify that by running ng serve. The terminal output should show you information about the server bundles generated, and you should be able to see the default app when going to http://localhost:4200. Open the Developer Tools and check the console to see that hydration is enabled. You'll see a message with hydration-related stats, such as the number of components and nodes hydrated. Speaking of hydration... Client Hydration If you open the src/app/app.config.ts in your new SSR application, you'll notice one interesting provider: provideClientHydration(). This provider is crucial for enabling hydration - a process that restores the server-side rendered application on the client. Hydration improves application performance by avoiding extra work to re-create DOM nodes. Angular tries to match existing DOM elements to the application's structure at runtime and reuses DOM nodes when possible. This results in a performance improvement measured using Core Web Vitals statistics, such as reducing the Interaction To Next Paint (INP), Largest Contentful Paint (LCP), and Cumulative Layout Shift (CLS). Improving these metrics also positively impacts SEO performance. Without hydration enabled, server-side rendered Angular applications will destroy and re-render the application's DOM, which may result in visible UI flicker, negatively impact Core Web Vitals like LCP, and cause layout shifts. Enabling hydration allows the existing DOM to be reused and prevents flickering. Event Replay and Improved Debugging With Angular 18, event replay, a feature that significantly enhances the SSR experience, came into developer preview. Event replay captures user interactions during the SSR phase and replays them once the application is hydrated. This ensures that user actions, such as adding items to a cart, are not lost during the hydration process, providing a seamless user experience even on slow networks. To enable event replay, you can add withEventReplay to your provideClientHydration call: ` Furthermore, Angular 18 takes another step towards making SSR a first-class citizen by enhancing the debugging experience with Angular DevTools. Now, DevTools include overlays and detailed error breakdowns, empowering developers to visualize and troubleshoot hydration issues directly in the browser. Constraints However, hydration imposes a few constraints on your application that are not present without hydration enabled. Your application must have the same generated DOM structure on both the server and the client. The hydration process expects the DOM tree to have the same structure in both environments, including whitespaces and comment nodes produced during server-side rendering. Direct DOM Manipulation The fact that server and client DOM structures must match means that components that manipulate the DOM using native DOM APIs or use innerHTML or outerHTML will encounter hydration errors. The errors are thrown because Angular is unaware of these changes and cannot resolve them during hydration. Examples include accessing the document, querying for specific elements, and injecting additional nodes using appendChild. Detaching DOM nodes and moving them to other locations will also cause errors. Direct DOM manipulation is generally considered bad practice in Angular, so I recommend refactoring your components to avoid it regardless of hydration. However, in warranted cases where refactoring is not feasible, you can use the ngSkipHydration attribute until a hydration-friendly solution can be implemented. You can use it directly in a template: ` or as a host binding: ` > Note: The ngSkipHydration attribute forces Angular to skip hydrating the entire component and its children. So use this attribute carefully, as, for example, applying it to your root application component would effectively disable hydration for the entire application. Valid HTML Structure Another constraint is that invalid HTML structures in component templates can result in DOM mismatch errors during hydration. Common issues include: - without a - inside a - inside an - inside another Again, if you have an invalid HTML, you should fix this regardless of hydration. If you are unsure about your HTML's validity, you can use the W3 validator to check it. Zoneless apps or custom Zone.js Hydration relies on a signal from Zone.js when it becomes stable. Custom or "noop" Zone.js implementations may thus disrupt the timing of this event, triggering the serialization or cleanup process too early or too late. This configuration is not yet fully supported. While Zoneless is already available in developer preview and we could assume this issue will be resolved when it lands as stable, there is no explicit ETA mentioned in the official roadmap. I18n One of the biggest blockers for adoption of client hydration was the lack of support for internationalization with hydration. By default, Angular 17 skipped hydration for components that used i18n blocks, re-rendering them from scratch. In Angular 18, however, hydration for i18n blocks got into developer preview. To enable hydration for i18n blocks, you can add withI18nSupport to your provideClientHydration call. ` Third-Party Libraries with DOM Manipulation The last thing to consider is third-party libraries that manipulate DOM, such as D3 charts. They could cause DOM mismatch errors when hydration is enabled. You can use the ngSkipHydration attribute to skip hydration for components rendered using these libraries. Conclusion The Angular team has been doing great work to make the framework more modern and competitive, hearing the community feedback and adjusting the roadmap accordingly. And SSR is an excellent example of that. With the introduction of non-destructive hydration in Angular 16 and making it stable in Angular 17, the Angular team has taken a significant step forward in making SSR a first-class citizen in Angular. The @angular/ssr package is now part of the Angular CLI, making adding SSR to your Angular application easier. The Angular team plans to make SSR the default in the next version, further solidifying its position in the Angular ecosystem. However, as with any new feature, there are some constraints and best practices to follow when using SSR with Angular. You should be aware of hydration's limitations and ensure your application is compatible with it. However, if you follow the guidelines provided by the Angular team, you should be able to take advantage of the benefits of SSR without any significant issues....

Jun 26, 2024

8 mins

AngularJavaScriptExpress.js

How to Create a Bot That Sends Slack Messages Using Block Kit and GitHub Actions

Have you ever wanted to get custom notifications in Slack about new interactions in your GitHub repository? If so, then you're in luck. With the help of GitHub actions and Slack's Block Kit, it is super easy to set up automated workflows that will send custom messages to your Slack channel of choice. In this article, I will guide you on how to set up the Slack bot and send automatic messages using GH actions. Create a Slack app Firstly, we need to create a new Slack application. Go to Slack's app page. If you haven't created an app before you should see: otherwise you might see a list of your existing apps: Let's click the Create an App button. Frpm a modal that shows up, choose From scratch option: In the next step, we can choose the app's name (eg. My Awesome Slack App) and pick a workspace that you want to use for testing the app. After the app is created successfully, we need to configure a couple of additional options. Firstly we need to configure the OAuth & Permissions section: In the Scopes section, we need to add a proper scope for our bot. Let's click Add an OAuth Scope in the Bot Token Scopes section, and select an incoming-webhook scope: Next, in OAuth Tokens for Your Workspace section, click Install to Workspace and choose a channel that you want messages to be posted to. Finally, let's go to Incoming Webhooks page, and activate the incoming hooks toggle (if it wasn't already activated). Copy the webhook URL (we will need it for our GitHub action). Create a Github Action Workflow In this section, we will focus on setting up the GitHub action workflow that will post messages on behalf of the app we've just created. You can use any of your existing repositories, or create a new one. Setting Up Secrets In your repository, go to Settings -> Secrets and variables -> Actions section and create a New Repository Secret. We will call the secret SLACK_WEBHOOK_URL and paste the url we've previously copied as a value. Create a workflow To actually send a message we can use slackapi/slack-github-action GitHub action. To get started, we need to create a workflow file in .github/workflows directory. Let's create .github/workflows/slack-message.yml file to your repository with the following content and commit the changes to main branch. ` In this workflow, we've created a job that uses slackapi/slack-github-action action and sends a basic message with an action run id. The important thing is that we need to set our webhook url as an env variable. This was the action can use it to send a message to the correct endpoint. We've configured the action so that it can be triggered manually. Let's trigger it by going to Actions -> Send Slack notification We can run the workflow manually in the top right corner. After running the workflow, we should see our first message in the Slack channel that we've configured earlier. Manually triggering the workflow to send a message is not very useful. However, we now have the basics to create more useful actions. Automatic message on pull request merge Let's create an action that will send a notification to Slack about a new contribution to our repository. We will use Slack's Block Kit to construct our message. Firstly, we need to modify our workflow so that instead of being manually triggered, it runs automatically when a pull requests to main branch is merged. This can be configured in the on section of the workflow file: ` Secondly, let's make sure that we only run the workflow when a pull request is merged and not eg. closed without merging. We can configure that by using if condition on the job: ` We've used a repository name (github.repository) as well as the user login that created a pull request (github.event.pull_request.user.login), but we could customize the message with as many information as we can find in the pull_request event. If you want to quickly edit and preview the message template, you can use the Slack's Block Kit Builder. Now we can create any PR, eg. add some changes to README.md, and after the PR is merged, we will get a Slack message like this. Summary As I have shown in this article, sending Slack messages automatically using GitHub actions is quite easy. If you want to check the real life example, visit the starter.dev project where we are using the slackapi/slack-github-action to get notifications about new contributions (send-slack-notification.yml) If you have any questions, you can always Tweet or DM me at @ktrz. I'm always happy to help!...

Oct 18, 2023

7 mins

GitHubGitHub Actions

How to Create a Website from Scratch with Nuxt Studio, Nuxt Content, and Nuxt UI

In this JS Drop, Simone is joined by Ferdinand and Baptiste from Nuxt Labs to explore the latest updates in the Nuxt ecosystem. Ferdinand kicks off with an introduction to Nuxt Labs and its dual mission of supporting the open-source Nuxt framework while building sustainable products like Nuxt Studio, Nuxt Content, and Nuxt UI. Baptiste takes over with a live demo, showcasing how to create a website from scratch using Nuxt Studio. He demonstrates the platform’s powerful content management features, showing how Nuxt Content integrates to manage and edit website content easily. Baptiste highlights Nuxt UI components and how they simplify coding by providing ready-to-use elements. The demo also features live editing and previews, making collaboration easier for both technical and non-technical users. Ferdinand wraps up by emphasizing Nuxt Studio’s user-friendly design and hints at exciting future updates, including branch management and internationalization support. This session highlights Nuxt Labs' commitment to enhancing the Vue.js ecosystem with versatile, user-focused tools. Follow Baptiste Leproux and Ferdinand Coumau: Baptiste Twitter: https://x.com/larbish Ferdinand Twitter: https://x.com/CoumauFerdinand Baptiste Linkedin: https://www.linkedin.com/in/baptiste-leproux-618842b0/ Ferdinand Linkedin: https://www.linkedin.com/in/ferdinand-coumau-nuxt/ Sponsored by This Dot...

Oct 25, 2024

1 min

NuxtJS

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What's New in @this-dot@route-config v1.2

RouteDataDirective (`*tdRouteData`)

RouteDataHasDirective (`*tdRouteDataHas`)

Summary

Chris Trześniewski

You might also like

Exploring Angular Forms: A New Alternative with Signals

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Let's innovate together!

You might also like

Exploring Angular Forms: A New Alternative with Signals

SSR Finally a First-Class Citizen in Angular?

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RouteDataDirective (*tdRouteData)

RouteDataHasDirective (*tdRouteDataHas)

Summary

Chris Trześniewski

Exploring Angular Forms: A New Alternative with Signals

SSR Finally a First-Class Citizen in Angular?

How to Create a Bot That Sends Slack Messages Using Block Kit and GitHub Actions

How to Create a Website from Scratch with Nuxt Studio, Nuxt Content, and Nuxt UI

Let's innovate together!

Exploring Angular Forms: A New Alternative with Signals

SSR Finally a First-Class Citizen in Angular?

How to Create a Bot That Sends Slack Messages Using Block Kit and GitHub Actions

How to Create a Website from Scratch with Nuxt Studio, Nuxt Content, and Nuxt UI

RouteDataDirective (`*tdRouteData`)

RouteDataHasDirective (`*tdRouteDataHas`)