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Armen Vardanyan

@armenvardanyan.dev

180 followers 220 following 120 posts

GDE for Angular, front-end team lead. I write articles and talk at conferences

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Armen Vardanyan @armenvardanyan.dev · Nov 21

If you don't know, I've authored a book about #Angular - aptly titled "Modern Angular"

It is approaching print publication and is already available online with early access

You can check it out here:
www.manning.com/books/modern...

Modern Angular

Discover the new features and techniques of the most modern versions of Angular.</b> The powerful Angular framework is ever-evolving, with each new iteration bringing amazing new modern features. Mod...

www.manning.com

Armen Vardanyan

@armenvardanyan.dev

Did you miss this week's stream?

We talked about Signals/RxJS, developed some examples, and explored a couple of useful articles

Curious whether RxJS will replace signals, want to know when to use which, or just trying to prepare for a migration? Watch it here:

www.youtube.com/watch?v=cbSt...

RxJS vs Signals

YouTube video by Angular Space

www.youtube.com

December 12, 2025 at 2:06 PM

Armen Vardanyan

@armenvardanyan.dev

I've been thinking, since in Armenia we celebrate Christmas on January 6th instead of December 25th, and the 25th is a Wednesday, why not do one final livestream and sum up the year for Angular? 😁

Would you watch it?

December 12, 2025 at 1:21 PM

Armen Vardanyan

@armenvardanyan.dev

During the latest livestream, we also explored two interesting articles touching on the topic of RxJS vs Signals.

Let's talk about them, as you should definitely check them out to get a better grasp of how everything works!

A top-down view of a wooden desk featuring a silver MacBook Pro laptop, a black tablet, and two disposable coffee cups. The laptop screen displays a code editor split into two panels: the left side is labeled "RxJS" and shows imports and a function using observables (e.g., of(), pipe(), tap(), switchMap()), and the right side is labeled "Signals" and shows imports and a function using signals (e.g., signal(), computed()). The title of the comparison on the screen is "RxJS vs Signals".

December 12, 2025 at 11:17 AM

Armen Vardanyan

@armenvardanyan.dev

Here's another example from yesterday's livestream

You do not need to manually `reload` a signal when the user clicks "next page". Instead, you should think of your resource as dependent on the `page` state and increment the page number when the user clicks. Super easy, fully declarative:

@Component({
template:
<button (click)="page.set(page() + 1)">Go to next page</button>
<span>{{ todo.value() | json }}</span>,
imports: [JsonPipe]
})
export class App {

page = signal(1);
todo = rxResource({
params: () => ({page: this.page()}),
stream: ({params}) => {
return this.#http.get<Todo[]>(
'https://jsonplaceholder.typicode.com/todos/' + params.page
)
},
});
}

December 11, 2025 at 1:48 PM

Armen Vardanyan

@armenvardanyan.dev

We did a lot of examples with Signals + RxJS on yesterday's livestream, I'm gonna post them all 😁

Here's an example of a resettable timer with `linkedSignal` and an RxJS `interval` Observable:

$@Component({ template: <span>{{ timer() }}</span> <button (click)="timer.set(0)">Reset</button> }) export class TimerComponent { timer = linkedSignal<number, number>({ // recompute each second source: toSignal( interval(1_000), {initialValue: 0} ), computation: (newValue, previous) => { // just increment by one each second return (previous?.value ?? 0) + 1; }, }); });$

December 11, 2025 at 12:36 PM

Armen Vardanyan

@armenvardanyan.dev

Just finished the episode! And again I did a long one...

But we discussed a lot!

December 10, 2025 at 7:10 PM

Armen Vardanyan

@armenvardanyan.dev

Join me in 30 minutes on today's livestream so we can find answers to all Dignals vs RxJS questions together!

December 10, 2025 at 4:31 PM

Armen Vardanyan

@armenvardanyan.dev

Don't forget to tune in today! We are going to answer the most crucial question: "When do we use signals and when do we use RxJS?" (and many more)

Tonight, at 4 PM UTC

December 10, 2025 at 1:58 PM

Armen Vardanyan

@armenvardanyan.dev

Do you know how to stop an `rxResource` from executing immediately so that we can trigger it later manually?

@Component({/* */})
export class SomeComponent {
readonly #dataService = inject(DataService);
data = rxResource({
// will this execute or not?
stream: () => this.dataService.getData(),
});
}

December 10, 2025 at 12:19 PM

Armen Vardanyan

@armenvardanyan.dev

What will this code do? And, more importantly, why?

import { timer } from 'rxjs';

@Component({/* */})
export class SomeComponent {
interval = toSignal(timer(0, 100), {requireSync: true});
}

December 10, 2025 at 11:17 AM

Armen Vardanyan

@armenvardanyan.dev

Here is the link to watch tomorrow's livestream!

Join us to discuss everything you need to know about RxJS + Signals

www.youtube.com/watch?v=cbSt...

RxJS vs Signals

This week, let's talk about RxJS and answer some burning questions I keep seeing Angular devs ask - Is RxJS no longer needed? - Should we replace Observables with Signals? - If we use both, how do…

www.youtube.com

December 9, 2025 at 11:51 AM

Armen Vardanyan

@armenvardanyan.dev

I love the excitement that @michaelsmalldev.bsky.social brings to our streams 😁

Michael Small @michaelsmalldev.bsky.social · 5d

CERTIFIED PLATNUM STREAM INCOMING

Great topic, looking forward to this

Armen Vardanyan @armenvardanyan.dev · 5d

I'm back 😁

This week, let's talk about RxJS and answer some burning questions I keep seeing Angular devs ask

- Is RxJS no longer needed?
- Should we replace Observables with Signals?
- If we use both, how do we understand when to reach out for what? (1/2)

December 8, 2025 at 2:57 PM

Armen Vardanyan

@armenvardanyan.dev

December 8, 2025 at 1:04 PM

Armen Vardanyan

@armenvardanyan.dev

No stream today! A very busy week at hand 😁

Promise to be back next week!

A high-angle shot of a wooden desk setup featuring two computer monitors and a black microphone on the left. In the center, open notebooks and a pen sit atop a weekly planner sheet with the handwritten text "BUSY WEEK." A white keyboard and mouse are positioned on the right side.

December 3, 2025 at 12:47 PM

Armen Vardanyan

@armenvardanyan.dev

Got featured on local news

(for a good reason 😁 )

tech.news.am/eng/news/642...

AI Takes Center Stage at JavaScript Conference Armenia 2025 | NEWS.am TECH - Innovations and science

Supported by major Armenian technology companies – including Krisp Technologies, Inc., Synergy International Systems, Ameriabank, and Mootq – the conference features technical presentations and Q&A…

tech.news.am

December 1, 2025 at 2:34 PM

Armen Vardanyan

@armenvardanyan.dev

Can you guess which of our livestreams was watched by the most people? 😁

A promotional graphic featuring a question and headshots of eight speakers.

A purple, space-themed graphic with the headline "CAN YOU GUESS WHICH LIVESTREAM HAD THE BIGGEST AUDIENCE?" and logos for X, YouTube, Twitch, and LinkedIn. It features circular headshots of eight speakers: Armen Vardanyan, Rainer Hahnekamp, Cagatay Civici, Roberto Heckers, Tomas Trajan, Alex Inkin, Gérôme Grignon, and Michael Small.

December 1, 2025 at 12:31 PM

Armen Vardanyan

@armenvardanyan.dev

For me, the biggest improvement that Signal Forms brings is how easy it is now to create custom control components

No more `ControlValueAccessor` and boilerplate, simply drop some inputs/model signal for value/disabled state/etc, and you're done!

Here's a reusable Rating component example:

@Component({
selector: 'app-rating',
template:
<div class="rating">
@for (star of stars; track $index) {
<span class="star"
[class.filled]="$index < value()"
[class.disabled]="disabled()"
(click)="value.set($index + 1)">★</span>
}
</div>,
})
export class RatingComponent {
value = model<number>(0);
disabled = model<boolean>(false);
stars = [1, 2, 3, 4, 5];
}

// elsewhere
<app-rating [field]="form.rating" />

December 1, 2025 at 11:15 AM

Armen Vardanyan

@armenvardanyan.dev

Custom validation is super easy with signal forms, even when the logic is a bit complex; no need to define a separate function, just use `validate` inline.

Here's an example of multiple string inputs (array), none of which can be empty:

Code example, see full code here: https://gist.github.com/Armenvardanyan95/fabb2f8d63e1ecad5b5571bfd8d76949

November 28, 2025 at 12:35 PM

Armen Vardanyan

@armenvardanyan.dev

Wow, already at least 472 people watched the Zoneless livestream

I feel zoneless is going to continue being a big topic, especially with how it makes Angular simpler again (like the new control flow and standalone)

Watch it here if you missed it: www.youtube.com/watch?v=hfyu...

A dashboard table row showing statistics for a broadcast titled "Pushing Zoneless to the Limit." The status is "ENDED," and the date is Nov 26, 2025 (9:00 PM - 10:43 PM). The metrics display 636 Minutes Watched, 606 Views, and 472 Viewers.

November 28, 2025 at 11:10 AM

Armen Vardanyan

@armenvardanyan.dev

It's a slow day, might post signal form examples 😁

@Component({
template: `
<form>
<input type="email" [field]="form.email" />
<input type="password" [field]="form.password" />
<form>
`,
imports: [Field]
})
export class LoginComponent {
credentials = signal({
email: '',
password: '',
});

form = form(credentials, path => {
required(path.email);
required(path.password);
});
}

November 28, 2025 at 10:39 AM

Armen Vardanyan

@armenvardanyan.dev

I hope I will continue posting here 😁

Michael Small @michaelsmalldev.bsky.social · 16d

ARMEN BACK ON THE REAL APP! This was a real cool stream.

Armen Vardanyan @armenvardanyan.dev · 16d

Maybe I should start by posting my latest livestream

We explored so much about Zoneless Angular!

www.youtube.com/live/hfyuzgP...

November 28, 2025 at 7:43 AM

Armen Vardanyan

@armenvardanyan.dev

During yesterday's livestream, we discovered that setting the change detection strategy to `OnPush` on the root component (AppComponent) actually does something

Change detection now runs once each time (as opposed to twice). I'm unsure what that means or why this happens. Anyone care to weigh in?