Introduction to Build a Modern Angular Application with Signals

Course Introduction

Project Architecture Build a Modern Angular Application with Signals

Project Architecture

This module initiates your journey by highlighting the significance of lightweight dependencies, improved reactivity, and optimized performance in application development using Angular 17. Understand the reasons driving the upgrade from previous Angular versions to Angular 17.

Introduction

Getting started with the concept of signals

The Concept of Signals

The importance of Signals over Change Detection and Zone.js

In this lesson, you will learn how to create our first Signals variable in Angular. You get to see how easy it is to declare variables compared to doing it with Observables which has a more robust boilerplate code.

How to Create a Signal

Here, you will get to learn about the different Reactive primitives available in Signals, which are writable signals, computed and effects.

Reactive Primitives in Signals

Discover the foundational concept of Signals within Angular and its relevance in the ecosystem. Understand the pivotal role Signals play, addressing performance concerns and simplifying Angular application development.

 Getting Started with Signals

This video provides an insight into what we are going to do in this module.

Module 3 Introduction

In this module, you’ll learn how to combine RxJS and Signals when working with HTTP requests from the REST API. We will learn how to work with the Interoperability API when dealing with asynchronous operations in Signals.

Fetching Data from the Server using RxJS

Here we get to modify the code we wrote previously to fetch data from the server. We go ahead to show the simplicity of Signals by converting the data gotten from the Observable into Signals making use of the Interoperability API.

Using the Interoperability API to convert Http requests to Signals

Combine RxJS and Signals to navigate HTTP requests from REST APIs. Learn to leverage the Interoperability API for managing asynchronous operations within Signals.

Signals and Http Requests

Module 4 Introduction

In this module, we get to display how to spread data across different components with the use of Signals.

Adding Items to the Shopping Cart

In this module, we will utilise Signals to increase and decrease the number of items to add to cart =, as well as integrate functionality to remove an item from cart.

Integrate Counter Functionality and Remove Items from Cart

In this lesson, we get a summary of all the items that have been added to the cart, which includes the number of items bought and the cart total.

Implement the Checkout Page

Exercise

In this lesson, we will take a look at how to handle errors in Signals.

Error Handling in Signals

Explore the techniques of disseminating data across various components using Signals, facilitating efficient communication and data exchange.

Sharing Data Between Different Components with Signals

We will do a review of all the concepts learned in the course and also look at the upcoming features to be integrated into Signals.

Wrapping up the Course

In the final module, we comprehensively review every concept that's been covered in this course. Additionally, this module provides insights into upcoming features to be integrated into Angular 17 Signals.

Course Wrap Up

### How The Course Works:

- The "Build a Modern Web Application using Angular Signals" course is a comprehensive online program spanning five modules. Discover how to effectively utilize Signals to manage the entire state of an Angular application, integrate the newly built-in control flows, employ deferrable views, navigate components using lazy loaded routes, and implement Standalone components.
- Remote Access: Take advantage of the course from any location, allowing you the flexibility to engage with the materials at your convenience.
- Self-Paced Learning: Tailor your learning experience to your schedule, enabling you to progress through the course content at your own pace.
- Community Engagement: Collaborate and learn alongside a diverse community of fellow students, fostering an environment of shared knowledge and support.
- Structured Learning: Experience a well-organized curriculum designed to provide a cohesive and comprehensive understanding of Angular Signals in a logical progression.

### Understanding the Challenges

Learning Angular 17 can present various hurdles and frustrations for those new to the technology. As individuals navigate their journey into this advanced framework, they commonly encounter several challenges:

- Complexity Barrier: The intricate architecture and extensive feature set of Angular 17 can overwhelm newcomers, posing a significant learning curve.
- State Management Complexity: Managing the state of an Angular application efficiently, especially with the nuances of Signals, can prove challenging for learners.
- Integration Puzzles: Integrating and harnessing newly built-in control flows, deferrable views, Standalone components, and lazy loaded routes can be intricate and perplexing.
- Navigational Complexity: Understanding the intricacies of lazy loaded routes and effective navigation between components can pose obstacles to a smooth learning experience.

Navigating through these complexities without guidance can hinder the progress of aspiring developers aiming to master Angular 17.


### Advantages of Learning Angular 17 in 2023

- Enhanced Performance: In 2023, Angular 17 offers optimized performance enhancements, enabling you to craft high-performing web applications capable of meeting modern user expectations.
- Cutting-Edge Features: Stay ahead in the web development landscape by mastering the latest built-in control flows, deferrable views, and other advanced functionalities unique to Angular 17.
- Industry Relevance: With Angular continuing to be a sought-after framework in the industry, mastering Angular 17 ensures you remain competitive and relevant in the job market.
- Improved Developer Experience: Angular 17 introduces refinements and enhancements that streamline the development process, providing a more efficient and enjoyable experience for developers.
- Scalability and Maintainability: Learning Angular 17 equips you with the knowledge to build scalable and maintainable applications, crucial factors in modern software development.

### Why Learn Angular 17 in 2023

Angular 17 stands at the forefront of web development frameworks in the current year, offering you several compelling reasons to dive into its intricacies:
Embrace the evolution of web development by mastering Angular 17 in 2023. This advanced version presents you with enhanced performance capabilities, cutting-edge features, and improved developer experiences. Remaining proficient in Angular ensures your relevance in a competitive industry, equipping you with the skills necessary to build scalable, high-performing applications that meet the demands of modern users.

### Course Content Overview

Course Overview:
Total Modules: **5**
Total Lessons: **12**
Total Video Runtime: **1 hour, 41 minutes**

### Summary:
This course is structured into five comprehensive modules, guiding you through the intricacies of Angular 17 Signals. From laying the groundwork with introductory concepts to diving deep into handling HTTP requests, sharing data between components, and culminating with a thorough review in the conclusion module, each section builds upon the last, empowering you to master Angular 17 Signals effectively.

Learn how to surgically manage state and optimize UI rendering with Angular Signals. This course introduces students to the world of Angular Signals, from reactive primitives to seamless interoperability between observables and signals. By the end of this course, you'll have learned how to build a highly performant, lightweight Angular application that features deferrable views, lazy loaded routes, and a PayPal-powered checkout flow. Additionally, you'll have learned the techniques needed to modernize older Angular applications so that they're able to fully leverage the power of Angular Signals.

Demystifying Reactivity with Angular Signals

Fetch data from a REST API making use of Signals.

Make use signals to add functionalities to the shopping cart

Checkout selected items from the cart using the available Signal APIs

How to manage state in an Angular application by making use of Signals

The importance of using Signals to enhance change detection

How to integrate a robust lazy loading approach, by making use of deferrable views and lazy loaded routes

Difference between using RxJS and Signals when working with data and asynchronous operations

How to structure an Angular application using Standalone components

How to work with the newly built-in control flows

Effective Error Handling in Signal-Based Programming

Welcome to this educational article discussing error handling in signal-based programming. This article will delve into an approach that utilizes the 'track hash block' to undo errors in signals. This approach leverages different types of notifications, including 'next', 'error', and 'complete', provided by observer boosts. Practical examples will be used to illustrate the concepts clearly. By the end of this article, readers should be able to effectively handle errors in signal-based programming.

A common challenge in signal-based programming is handling errors in states and intersections. These errors can be handled more effectively by using the 'track hash block' within signals. Observer boosts come in handy here, as they can return three types of notifications: 

. It is important to note that signals can only subscribe to the 

Let's consider an example where we have an endpoint in our product service file (product.service.cs) that returns '/products'. We will intentionally create an error by adding an extra 'S' to the endpoint and saving it. If we check our console output, we will notice an HTTP error response. However, this error is currently not displayed on our webpage due to our existing implementation.

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title: Error Handling in Signals
description: In this lesson, we will take a look at how to handle errors in Signals.
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privateVideoUrl: https://stream.mux.com/vzlKRc9uGg2S1XFCxz01jVkBYWzs3N9s00K1GtOmSvSIM.m3u8
isPublicLesson: true
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# Effective Error Handling in Signal-Based Programming

## Introduction

Welcome to this educational article discussing error handling in signal-based programming. This article will delve into an approach that utilizes the 'track hash block' to undo errors in signals. This approach leverages different types of notifications, including 'next', 'error', and 'complete', provided by observer boosts. Practical examples will be used to illustrate the concepts clearly. By the end of this article, readers should be able to effectively handle errors in signal-based programming.

## Discussion

A common challenge in signal-based programming is handling errors in states and intersections. These errors can be handled more effectively by using the 'track hash block' within signals. Observer boosts come in handy here, as they can return three types of notifications: `next`, `error`, and `complete`. It is important to note that signals can only subscribe to the `next` notification.

Let's consider an example where we have an endpoint in our product service file (product.service.cs) that returns '/products'. We will intentionally create an error by adding an extra 'S' to the endpoint and saving it. If we check our console output, we will notice an HTTP error response. However, this error is currently not displayed on our webpage due to our existing implementation.

deji adesoga

As can see, we've covered a lot of buying this course, but I would like to end

by covering a bit of error handling when it comes to signals.

To provide more context on this, in one of the discussion channels of the

repo, we're provided with a bit of insight on how to go about these

We're provided with a bit of information on how to use the track hash block to

On page to observables, which are able to return three types of notifications,

are next, error and completes, signals are only wrap-ups that are able to

the next notification, which means observables are able to undo errors easily

notifications that helps in returning the error compared to signals.

For that doesn't mean we can't undo errors in signals.

Based on the information provided in this GitHub discussion, we're going to try

the information provided here in our code.

To do that, we're going to simulate some form of errors in our product service

So, it is just a visual studio code in our product.service.ts file, where we

We're going to add an extra S and then save to see what we get in the console.

So I'm just going to open up visual studio code and then see if we have any

errors based on our current implementation.

As can see, we have this HTTP error response being returned.

But there's no way we can display this currently on the page based on our

To attempt to do that, what I'm going to do is a straight to a service file and

This variable is going to be called products.

And in fact, what I'm going to do is assign that product variable to the value

So what I'm going to do is copy this product signal, then play what we have

So we have the product variable, then we can now make use of the product signal

we now hold the entire response as well as the error for this new

So we can just make use of the computed reactive primitives.

And within the computed reactive primitives, we can create a try-catch block.

So I'm just going to say try and then patch, which is going to take in an

For the try-block, we're going to return these products.

Oh, we can make it products since it's written in an area of products.

So without implementation, why would we return this particular set of products

If the request is successful, boy, in the case of an error, we need to return

message by making use of the return keyword.

I'm just going to say return on so.log, error, time we are just going to save

If we have the signal logging the error in this particular block, as you can

service, see as well on line 22, which is where we have this particular log, we

What all I would like to do is to display an alert box inside of our project

So to do that, it illustrates to the velocity of code.

What I'm going to do is I'm going to say alert, error, and because we want to

message inside of the object, we can just make use of a bracket notation and

Boy, we have an error that says error is type of unknown.

In this situation, we don't know what objects might be returned in the error

So I'm just going to pass in a type of any.

There we can save, it passes the browser with what the products refresh.

And then we get an analysis HTTP response for local or products not found.

That is, it's letting us know that the URL for this particular API is incorrect

With this, we're able to get an insight into one of the ways in which errors

Over time, as improvements are made on signals, we'll get to have more ways and

on how to fix errors when it comes to signals.

For now, we'll get an introductory view on how to undo error with signals.

And that's it for this lesson thank you very much for watching.