Angular

Angular News: Angular’s SDK, Best Practices for Upgrading, Material Design, & Angular Directives

Oct 28, 2019

5 min read

Recently, there has been a lot of buzz on Angular’s SDK (a new version of the CLI), the never ending AngularJS to Angular upgrade question, Angular Material’s progress, and how to think of Angular’s directives in a way that may be more useful to your application development.

In these videos, we cover the latest Angular news with Hans Larsen (@hanslatwork)and Pete Bacon Darwin (@petebd) from the Angular Core Team, Elad Bezalel (@elad_bezalel) from the Angular Material Core team, Mike Brocchi (@Brocco)from the Angular-CLI Core Team, and Justin Searls (@searls), a JavaScript developer and speaker.

Angular CLI, SDK, and Angular 4.0

Hans Larsen Reveals Upcoming Angular Products and Discusses SDK

As a member of the core angular team, Hans has been working on SDK — the next version of CLI. He says his work involves helping developers with efficiency, by allowing them to manage their apps and projects, even before making an appearance to the browser. He’s also looking to make improvements to better the interface.

Hans further explains that individuals who are used to the current CLI, will be able to use the new version with ease. Default features will remain the same, and the upgrade path will be straightforward, made to support Angular 4.0. Having said that, SDK will be entirely redesigned from the ground up as a blueprint library. All very exciting news for the Angular community.

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Angular, AngularJS, and Ng-upgrade

Pete Bacon Darwin, Angular Core Team on The Best Way to Upgrade Your AngularJS Applications

As a contributor who is still working on one of the biggest JavaScript frameworks, he talks about how to slow down the development of AngularJS in order to allow migration towards Angular. The parts of AngularJS that many people came to love still exist in Angular, which is more reason to help push developers towards Angular.

Easy upgrade can be accomplished with ngUpgrade, which allows angular and angularjs to run at the same time. This way, developers can continue to keep uptime for their clients while moving their code one part at a time. NgUpgrade is one of many potential solutions for the switch over to Angular.

Going back to when Angular was introduced, Pete talks about whether there was a better way to prepare the community for the migration. From his point of view, due to the existing architecture of Angularjs, there wasn’t anything that could’ve been done differently, as the Angular now is much more advanced in comparison.

The interview ends with Pete describing the Angular community and different frameworks coming together and converging ideas. He believes comparing and discussing ideas helps immensely with solutions as JavaScript and modern web in general continues to evolve.

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Angular Material + Angular Material 2

Elad Bezalel, Angular Material Core Team: Being on The Angular Material Team

Elad Bezalel is a part of the Angular Material Team and is currently working on Material 2 components and features. He walks us through how he became a part of the team and what intrigued him the most about Material. Elad is very confident about this project and encourages developers to use it as an aid with their designing. He is still working on improvements and creating more components, but seeing as Material 2 is in its beta stage, it is ready for anyone who want to use it.

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Angular Directives

Mike Brocchi and His Thoughts on Angular Directives

Mike describes becoming a member of the Angular-CLI Core team and contributing to the angular community to be more involved. In this interview, he talks about directives in detail, starting with the fact that they are underrated and should be promoted. He hopes in the future, people will be more aware of how to use directives effectively. He explains how it’s still a key part of Angular, even beyond Angularjs.

With directives, developers can add behaviours to their applications without having to separate components or add logic into their component.This could be done for many situations.

Mike also discusses when not to use a directive and expands a little on host binding and host listening. He then gives a breakdown of what else directives can accomplish, such as improving accessibility or being used to access templates from existing components. Mike also describes the differences between different types of directives.

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Angular Community + Open Sourcing Projects

Overcoming the Challenges of being a Developer: Justin Searls Shares his Experience

Justin discusses what it’s like to learn Angular (coming from ember) and how frameworks have evolved, becoming more intense and “robust”. Although this is a good thing, he mentions it being important for there to be room for inventiveness, as this is why he chose to explore javascript in the first place. In his words “we need to make space for creativity and divergence instead of being on a unilateral path to solving applications”. This can easily be done with tools such as babel, which allows developers to experiment with different language features.

Justin elaborates on the non-technical side of being a developer. He talks about the feelings of frustration and upset, lack of motivation, and other barriers that come with being a developer. He then discusses how starting small, creative projects and open sourcing ideas can help channel these negative emotions, and turn them into something positive and applicable, as opposed to solely unbearable. He encourages developers to present their ideas even when they’re uncertain of the outcome, and gives tips on how to gain recognition in an effective and modest manner. All in all, Justin strives to provide a model for the industry, to normalize talking about weaknesses and shortcomings, no matter who you are, where you’re from, or what background you have as a developer.

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The Angular team has been consistently releasing new updates to the framework. You can learn more about the Angular framework at https://angular.io/.

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A Guide to Custom Angular Attribute Directives

When working inside of Angular applications you may have noticed special attributes such as NgClass, NgStyle and NgModel. These are special attributes that you can add to elements and components that are known as attribute directives. In this article, I will cover how these attributes are created and show a couple of examples. What are Attribute Directives? Angular directives are special constructs that allow modification of HTML elements and components. Attribute directives are also applied through attributes, hence the name. There exist other types of directives such as structural directives as well, but we’re just going to focus on attribute directives. If you’ve used Angular before then you have almost certainly used a couple of the attribute directives I mentioned earlier before. You are not limited to just the built-in directives though. Angular allows you to create your own! Creating Attribute Directives Directives can be created using code generation via the ng CLI tool. ` ng generate directive ` This will create a file to house your directive and also an accompanying test file as well. The contents of the directive are very barebones to start with. Let’s take a look. ` import { Directive } from '@angular/core'; @Directive({ selector: '[appExample]', }) export class ExampleDirective { constructor() {} } ` You will see here that directives are created using a @Directive decorator. The selector in this case is the name of the attribute as it is intended to be used in your templates. The square brackets around the name make it an attribute selector, which is what we want for a custom attribute directive. I would also recommend that a prefix is always used for directive names to minimize the risk of conflicts. It should also go without saying to avoid using the ng prefix for custom directives to avoid confusion. Now, let’s go over the lifecycle of a directive. The constructor is called with a reference to the ElementRef that the directive was bound to. You can do any initialization here if needed. This element reference is dependency injected, and will be available outside the constructor as well. You can also set up @HostListener handlers if you need to add functionality that runs in response to user interaction with the element or component, and @Input properties if you need to pass data to the directive. Click Away Directive One useful directive that doesn’t come standard is a click away directive. This is one that I have used before in my projects, and is very easy to understand. This directive uses host listeners to listen for user input, and determine whether the element that directive is attached to should be visible or not after the click event occurs. ` @Directive({ selector: '[appClickAway]', }) export class ClickAwayDirective { @Output() onClickAway: EventEmitter = new EventEmitter(); constructor(private elementRef: ElementRef) {} @HostListener('document:click', ['$event']) onClick(event: PointerEvent): void { if (!this.elementRef.nativeElement.contains(event.target)) { this.onClickAway.emit(event); } } } ` There are a few new things in this directive we’ll briefly go over. The first thing is the event emitter output onClickAway. A generic directive isn’t going to know how to handle click away behavior by itself as this will change based on your use case when using the directive. To solve this issue, we make the directive emit an event that the user of the directive can listen for. The other part is the click handler. We use @HostListener to attach a click handler so we can run our click away logic whenever clicks are done. The one interesting thing about this directive is that it listens to all click events since we’ve specified ‘document’ in the first parameter. The reason for this is because we care about listening for clicking anything that isn’t the element or component that the directive is attached to. If we didn’t do this, then the event handler would only fire when clicking on the component the directive is attached to, which defeats the purpose of a click away handler. Once we’ve determined the element was not clicked, we emit the aforementioned event. Using this directive makes it trivial to implement click away functionality for both modals and context menus alike. If we have a custom dialog component we could hook it up like this: ` Dialog Box This is a paragraph with content! ` If you want to see this directive in action, then you can find it in our blog demos repo here. Drag and Drop Directive Another useful directive is one that assists with drag and drop operations. The following directive makes elements draggable, and executes a function with a reference to the location where the element was dragged to. ` @Directive({ selector: '[appDragDrop]', }) export class DragDropDirective implements OnInit, OnDestroy { @Output() onDragDrop: EventEmitter = new EventEmitter(); mouseDown$ = new Subject(); mouseUp$ = new Subject(); destroy$ = new Subject(); constructor(private elementRef: ElementRef) {} ngOnInit(): void { this.mouseDown$ .pipe(takeUntil(this.destroy$)) .pipe(exhaustMap(() => this.mouseUp$.pipe(take(1)))) .subscribe((event) => { if ( event.target && event.target instanceof Element && !this.elementRef.nativeElement.contains(event.target) ) { this.onDragDrop.emit(event); } }); } ngOnDestroy(): void { this.destroy$.next(null); this.destroy$.complete(); } @HostListener('mousedown', ['$event']) onMouseDown(event: MouseEvent): void { this.mouseDown$.next(event); } @HostListener('document:mouseup', ['$event']) onMouseUp(event: MouseEvent): void { this.mouseUp$.next(event); } } ` Just like the previous directive example an event emitter is used so the user of the directive can associate custom functionality with it. RxJs is also utilized for the drag and drop detection. This directive uses the exhaustMap function to create an observable that emits both after a mouse down, and finally a mouse up is done. With that observable, we can subscribe to it and call the drag and drop callback so long as the element that’s dragged on isn’t the component itself. Note how the mouse down event is local to the component while the mouse up event is attached to the document. For mouse down, this is done since we only want the start of the dragging to be initiated from clicking the component itself. The mouse up must listen to the document since the dragging has to end on something that isn’t the component that we’re dragging. Just like the previous directive, we simply need to reference the attribute and register an event handler. ` Drag me over something! ` Conclusion In this article, we have learned how to write our own custom attribute directives and demonstrated a couple of practical examples of directives you might use or encounter in the real world. I hope you found this introduction to directives useful, and that it helps you with writing your own directives in the future! You can find the examples shown here in our blog demos repository if you want to use them yourself....

May 31, 2023

4 mins

Angular

Angular 17: Continuing the Renaissance

Angular 17: A New Era November 8th marked a significant milestone in the world of Angular with the release of Angular 17. This wasn't just any ordinary update; it was a leap forward, signifying a new chapter for the popular framework. But what made this release truly stand out was the unveiling of Angular's revamped website, complete with a fresh brand identity and a new logo. This significant transformation represents the evolving nature of Angular, aligning with the modern demands of web development. To commemorate this launch, we also hosted a release afterparty, where we went deep into its new features with Minko Gechev from the Angular core team, and Google Developer Experts (GDEs) Brandon Roberts, Deborah Kurata, and Enea Jahollari. But what exactly are these notable new features in the latest version? Let's dive in and explore. The Angular Renaissance Angular has been undergoing a significant revival, often referred to as Angular's renaissance, a term coined by Sarah Drasner, the Director of Engineering at Google, earlier this year. This revival has been particularly evident in its recent versions. The Angular team has worked hard to introduce many new improvements, focusing on signal-based reactivity, hydration, server-side rendering, standalone components, and migrating to esbuild and Vite for a better and faster developer experience. This latest release, in particular, marks many of these features as production-ready. Standalone Components About a year ago, Angular began a journey toward modernity with the introduction of standalone components. This move significantly enhanced the developer experience, making Angular more contemporary and user-friendly. In Angular's context, a standalone component is a self-sufficient, reusable code unit that combines logic, data, and user interface elements. What sets these components apart is their independence from Angular's NgModule system, meaning they do not rely on it for configuration or dependencies. By setting a standalone: true` flag, you no longer need to embed your component in an NgModule and you can bootstrap directly off that component: `typescript // ./app/app.component.ts @Component({ selector: 'app', template: 'hello', standalone: true }) export class AppComponent {} // ./main.ts import { bootstrapApplication } from '@angular/platform-browser'; import { AppComponent } from './app/app.component'; bootstrapApplication(AppComponent).catch(e => console.error(e)); ` Compared to the NgModules way of adding components, as shown below, you can immediately see how standalone components make things much simpler. `ts // ./app/app.component.ts import { Component } from '@angular/core'; @Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.css'], }) export class AppComponent { title = 'CodeSandbox'; } // ./app/app.module.ts import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { AppComponent } from './app.component'; @NgModule({ declarations: [ AppComponent ], imports: [ BrowserModule ], providers: [], bootstrap: [AppComponent] }) export class AppModule { } // .main.ts import { platformBrowserDynamic } from '@angular/platform-browser-dynamic'; import { AppModule } from './app/app.module'; platformBrowserDynamic() .bootstrapModule(AppModule) .catch((err) => console.error(err)); ` In this latest release, the Angular CLI now defaults to generating standalone components, directives, and pipes. This default setting underscores the shift towards a standalone-centric development approach in Angular. New Syntax for Enhanced Control Flow Angular 17 introduces a new syntax for control flow, replacing traditional structural directives like ngIf` or `ngFor`, which have been part of Angular since version 2. This new syntax is designed for fine-grained change detection and eventual zone-less operation when Angular completely migrates to signals. It's more streamlined and performance-efficient, making handling conditional or list content in templates easier. The @if` block replaces `*ngIf` for expressing conditional parts of the UI. `ts @if (a > b) { {{a}} is greater than {{b}} } @else if (b > a) { {{a}} is less than {{b}} } @else { {{a}} is equal to {{b}} } ` The @switch` block replaces `ngSwitch`, offering benefits such as not requiring a container element to hold the condition expression or each conditional template. It also supports template type-checking, including type narrowing within each branch. ```ts @switch (condition) { @case (caseA) { Case A. } @case (caseB) { Case B. } @default { Default case. } } ``` The @for` block replaces `*ngFor` for iteration and presents several differences compared to its structural directive predecessor, `ngFor`. For example, the tracking expression (calculating keys corresponding to object identities) is mandatory but offers better ergonomics. Additionally, it supports `@empty` blocks. `ts @for (item of items; track item.id) { {{ item.name }} } ` Defer Block for Lazy Loading Angular 17 introduces the @defer` block, a dramatically improving lazy loading of content within Angular applications. Within the `@defer` block framework, several sub-blocks are designed to elegantly manage different phases of the deferred loading process. The main content within the `@defer` block is the segment designated for lazy loading. Initially, this content is not rendered, becoming visible only when specific triggers are activated or conditions are met, and after the required dependencies have been loaded. By default, the trigger for a `@defer` block is the browser reaching an idle state. For instance, take the following block: it delays the loading of the calendar-imp` component until it comes into the viewport. Until that happens, a placeholder is shown. This placeholder displays a loading message when the `calendar-imp` component begins to load, and an error message if, for some reason, the component fails to load. `ts @defer (on viewport) { } @placeholder { Calendar placeholder } @loading { Loading calendar } @error { Error loading calendar } ` The on` keyword supports a wide a variety of other conditions, such as: - idle` (when the browser has reached an idle state) - interaction` (when the user interacts with a specified element) - hover` (when the mouse has hovered over a trigger area) - timer(x)` (triggers after a specified duration) - immediate` (triggers the deferred load immediately) The second option of configuring when deferring happens is by using the when` keyword. For example: `ts @defer (when isVisible) { } ` Server-Side Rendering (SSR) Angular 17 has made server-side rendering (SSR) much more straightforward. Now, a --ssr` option is included in the `ng new` command, removing the need for additional setup or configurations. When creating a new project with the `ng new` command, the CLI inquires if SSR should be enabled. As of version 17, the default response is set to 'No'. However, for version 18 and beyond, the plan is to enable SSR by default in newly generated applications. If you prefer to start with SSR right away, you can do so by initializing your project with the `--ssr` flag: `shell ng new --ssr ` For adding SSR to an already existing project, utilize the ng add` command of the Angular CLI: `shell ng add @angular/ssr ` Hydration In Angular 17, the process of hydration, which is essential for reviving a server-side rendered application on the client-side, has reached a stable, production-ready status. Hydration involves reusing the DOM structures rendered on the server, preserving the application's state, and transferring data retrieved from the server, among other crucial tasks. This functionality is automatically activated when server-side rendering (SSR) is used. It offers a more efficient approach than the previous method, where the server-rendered tree was completely replaced, often causing visible UI flickers. Such re-rendering can adversely affect Core Web Vitals, including Largest Contentful Paint (LCP), leading to layout shifts. By enabling hydration, Angular 17 allows for the reuse of the existing DOM, effectively preventing these flickers. Support for View Transitions The new View Transitions API, supported by some browsers, is now integrated into the Angular router. This feature, which must be activated using the withViewTransitions` function, allows for CSS-based animations during route transitions, adding a layer of visual appeal to applications. To use it, first you need to import withViewTransitions`: `ts import { provideRouter, withViewTransitions } from '@angular/router'; ` Then, you need to add it to the provideRouter` configuration: `ts bootstrapApplication(AppComponent, { providers: [ provideRouter(routes, withViewTransitions()) ] }) ` Other Notable Changes - Angular 17 has stabilized signals, initially introduced in Angular 16, providing a new method for state management in Angular apps. - Angular 17 no longer supports Node 16. The minimal Node version required is now 18.13. - TypeScript version 5.2 is the least supported version starting from this release of Angular. - The @Component` decorator now supports a `styleUrl` attribute. This allows for specifying a single stylesheet path as a string, simplifying the process of linking a component to a specific style sheet. Previously, even for a single stylesheet, an array was required under `styleUrls`. Conclusion With the launch of Angular 17, the Angular Renaissance is now in full swing. This release has garnered such positive feedback that developers are showing renewed interest in the framework and are looking forward to leveraging it in upcoming projects. However, it's important to note that it might take some time for IDEs to adapt to the new templating syntax fully. While this transition is underway, rest assured that you can still write perfectly valid code using the old templating syntax, as all the changes in Angular 17 are backward compatible. Looking ahead, the future of Angular appears brighter than ever, and we can't wait to see what the next release has in store!...

Nov 20, 2023

6 mins

AngularAngular NewTypeScriptJavaScript

Software Team Leadership: Risk Taking & Decision Making with David Cramer, Co-Founder & CTO at Sentry

In this episode of the engineering leadership series, Rob Ocel interviews David Cramer, co-founder and CTO of Sentry, delving into the importance of decision-making, risk-taking, and the challenges faced in the software engineering industry. David emphasizes the significance of having conviction and being willing to make decisions, even if they turn out to be wrong. He shares his experience of attending a CEO event, where he discovered that decision-making and conflict resolution are struggles even for successful individuals. David highlights the importance of making decisions quickly and accepting the associated risks, rather than attempting to pursue multiple options simultaneously. He believes that being decisive is crucial in the fast-paced software engineering industry. This approach allows for faster progress and adaptation, even if it means occasionally making mistakes along the way. The success of Sentry is attributed to a combination of factors, including market opportunity and the team's principles and conviction. David acknowledges that bold ideas often carry a higher risk of failure, but if they do succeed, the outcome can be incredibly significant. This mindset has contributed to Sentry’s achievements in the industry. The interview also touches on the challenges of developing and defending opinions in the software engineering field. David acknowledges that it can be difficult to navigate differing viewpoints and conflicting ideas. However, he emphasizes the importance of standing by one's convictions and being open to constructive criticism and feedback. Throughout the conversation, David emphasizes the need for engineering leaders to be decisive and take calculated risks. He encourages leaders to trust their instincts and make decisions promptly, even if they are uncertain about the outcome. This approach fosters a culture of innovation and progress within engineering teams. The episode provides valuable insights into the decision-making process and the challenges faced by engineering leaders. It highlights the importance of conviction, risk-taking, and the ability to make decisions quickly in the software engineering industry. David's experiences and perspectives offer valuable lessons for aspiring engineering leaders looking to navigate the complexities of the field....

Nov 28, 2023

2 mins

Software EngineeringEngineering Leadership