Qwik

How to Build Apps with Great Startup Performance Using Qwik

Published Dec 9, 2022

Updated Feb 13, 2023

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This article was written over 18 months ago and may contain information that is out of date.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

In this article, we will recap the JS Drops Qwik workshop with Misko Hevery. This workshop provided an overview on Qwik, its unique features and a look at some example components. We will also address some of the questions raised at the end of the workshop.

If you want to learn more about Qwik with Misko Hevery, then please check out this presentation on This Dot Media’s YouTube Channel. Also don’t forget to subscribe to get the latest on all things web development.

What is Qwik?
How to create a Counter Component in Qwik
Unique features of Qwik
Questions asked during the workshop
Conclusion

What is Qwik?

Qwik is a web framework that builds fast web applications with consistent performance at scale regardless of size or complexity.

To get started with Qwik, run the following command:

npm create qwik@latest

The Qwik CLI will prompt options to scaffold a starter project on your local machine.

To start the demo application, run npm start and navigate to http://127.0.0.1:5173/ in the browser.

How to create a Counter Component in Qwik

Create a sub-directory in the routes directory named counter and add an index.tsx file with the component definition below.

import { component$, useStore } from "@builder.io/qwik";

export default component$(() => {
  const store = useStore({
    count: 0
  });

  return (
    <div>
      <div>Counter: {store.count}</div>
      <button onClick$={() => store.count++}>Increment</button>
    </div>
  )

})

Now navigate to http://127.0.0.1:5173/counter and you should see the counter component rendered on the page.

Unique features of Qwik

Directory Based Routing

Qwik is a directory-based routing framework. When we initiated Qwik, it created a routes sub-directory in the src directory and added index and layout files for route matching.

The index.tsx is the base route component and the layout.tsx is the component for handling the base page layout.

The sub-directories in the route directory serve as the application’s structure for route matching with its index.tsx files as the route components. Every index.tsx file does a look up for the layout component. If it doesn’t exist in the same directory, then it moves up to the parent directory.

// layout.tsx

import { component$, Slot } from '@builder.io/qwik';
import Header from '../components/header/header';

export default component$(() => {
  return (
    <>
      <main>
        <Header />
        <section>
          <Slot />
        </section>
      </main>
      <footer>
        <a href="https://www.builder.io/" target="_blank">
          Made with ♡ by Builder.io
        </a>
      </footer>
    </>
  );
});

Slots in Qwik

Qwik uses slots as a way of connecting content from the parent component to the child projection.

The parent component uses the q:slot attribute to identify the source of the projection and the element to identify the destination of the projection.

To learn more about slots, please check out the Qwik documentation.

Very little JavaScript in production

In production, Qwik starts the application with no JavaScript at startup, which makes the startup performance really fast.

To see this in action, open the browser’s dev tools, click on the Network tab, and on the Filter tab select JS.

You will notice the Vite files for hot module reloading are currently the only JavaScript files served which will not be shipped to production.

Go to the filter tab and check the invert checkbox then in the filter input type select Vite.

Resumability with Qwik

Qwik applications do not require hydration to resume an application on the client. To see this in action, click on the increment button and observe the browser’s dev tools network tab. You will notice Qwik is downloading only the required amount of JavaScript needed.

The way Qwik attaches the event to the DOM and handles the state of components is that it serializes the attribute, which tells the browser where to download the event handler and its state. To learn more about serialization with Qwik, read through the Qwik documentation.

By default, the code associated with the click event will not download until the user triggers that event. On this interaction, Qwik will only download the minimum code for the event handler to work.

To learn more about Qwik events, please read through the [documentation] (https://qwik.builder.io/docs/components/events/#events).

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.

About the author(s)

Hassan Sani
@inidaname @inidaname

The Journey To Making A New Framework: TanStack Start with Tanner Linsley

Danny Thompson, Director of Technology at This Dot Labs, talks with Tanner Linsley, Creator of TanStack, about his latest project, TanStack Start. They discuss the challenges of existing frameworks like Next.js and Remix, the development of TanStack Router, and the future of React Server Components. Tanner also explains how caching strategies and fine-grained invalidation can transform the user experience. Chapters - - Introduction & Tanner’s Background (00:00) - Going Full-Time on TanStack (01:00) - The Birth of TanStack Router (02:21) - Why Build Another Framework? (04:00) - React Server Components: Potential & Limitations (07:05) - Fine-Grained Cache Invalidation & UX (09:02) - Parallel Data Fetching in Routing (13:39) - TanStack Start: Alpha & Future Plans (16:41) - Where to Learn More About TanStack (18:48) Find Tanner Linsley on Social Media Twitter: https://x.com/tannerlinsley Linkedin: https://www.linkedin.com/in/tannerlinsley/ Github: https://github.com/tannerlinsley TanStack: https://tanstack.com/ Sponsored by Wix Studio...

Oct 9, 2024

1 min

TanStack QueryJavaScriptReact

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

How to Create Better Test Coverage Using Cypress 10

Testing is an integral part of software development, and it is important that all developers learn best testing practices. Jordan Powell, DX engineer at Cypress and Angular Google Developer Expert, has some tips to share with developers on how to write better tests using Cypress 10. In this article, we will take a look at Powell’s tips for writing end-to-end tests, component tests, and advanced testing patterns in Cypress. If you want to learn more from Jordan Powell, please check out his Advanced Cypress JS Drop training. Table of Contents - Why is Testing important? - Types of Testing - A new take on the testing pyramid - Differences between end-to-end testing and component testing - Jordan Powell’s best practices for E2E testing - Don’t use HTML Native selectors - Use Closures - Independent Test - Use Route Aliases - Setting a Global baseUrl - Jordan Powell’s Best Practices for Component Testing - Default Config Mount - Cypress Intercept - Use createOutputSpy - Jordan Powell’s Advanced Cypress Patterns - Session - Origin - Conclusion Why is Testing important? Software testing identifies issues within the application, and helps ensure that only high quality products are shipped to the user. Here are Jordan Powell’s reasons on why testing is important, and how it helps developers: Documentation: Good testing coverage will result in developers creating stronger test plans and better QA testing for new releases. Confidence: Writing good tests allows developers to build new features in confidence because the applications are working as intended. Safe Refactoring: Good test coverage leads to less refactoring down the road, and provides developers more time to work on new features. Improved UX: Good test coverage provides better UX (User Experience) for the end user because the application is working as intended. Types of Testing E2E, Integration, and Unit testing are three common methods for testing software applications. Unit Test: Unit testing serves as the foundation of the test pyramid. If you're working in a functional language, a unit will most likely be a single function. Your unit tests will call a function with different parameters and ensure that it returns the expected values. In an object-oriented language, a unit can range from a single method to an entire class. Integration test: Integration testing is where individual components of your application are tested as a group. End-to-end testing: E2E Testing is a technique that tests your app from the web browser through to the back end of your application, as well as testing integrations with third-party APIs and services. These types of tests are great at making sure your entire app is functioning as a cohesive whole. A new take on the testing pyramid In Jordan Powell’s Advanced Cypress JS Drop training, he challenges developers to rethink the traditional testing pyramid, and believes that component testing should also be included. Component Testing with Cypress 10 allows developers to test individual components quickly, regardless of its complexity. Component tests differ from end-to-end tests in that instead of visiting a URL to pull up an entire app, a component can be "mounted" and tested on its own. Differences between end-to-end testing and component testing Here are a few key differences between End-to-end and component testing: | End-to-end testing | Component testing | | ------------------------------------------------------- | ------------------------------------------------------------------------ | | The entire application and all of its layers are tested | Only the independent components are tested | | Testing can be done by developers and QA Teams | Testing is done by the developers | | Often requires a complex setup | No extra configuration for CI(Continuous Integration) environments needed | | Initialization command: cy.visit(url) | Initialization command: cy.mount() | Jordan Powell’s best practices for E2E testing Don’t use HTML Native selectors It is not good practice to use element selectors, id attributes, or class attributes when writing End-to-end tests. Using HTML Native selectors can lead to team members refactoring tests later on, or changing attributes which could affect the tests. Jordan Powell recommends using data attributes that can inform the team that this is a test attribute. When other team members need to change anything, they will be aware of the function of the attribute and what it may affect. Use Closures Jordan warns against assigned return values for Cypress assertions, and recommends using closures to access the Commands yield like this: ` Independent Test It is not good practice to combine related tests. Jordan Powell suggests that tests should be run independently from one another without sharing or relying on other test states. If test suites are related in any way, run the related properties or methods before each of the test runs, like in the code below: ` Use Route Aliases Another recommended practice is to use route aliases to guard Cypress against proceeding until an explicit condition is met. ` Setting a Global baseUrl It is bad practice to use hardcoded URL strings for the baseUrl because it will eventually fail when the environment changes. Instead, Powell recommends using a config file that holds the environment baseUrl. Jordan Powell’s Best Practices for Component Testing All of the code examples in this next section will be for Angular, but Cypress component testing works for all major Frontend JavaScript frameworks. Default Config Mount Component testing takes two parameters: the component to mount, and the object for configuration. A Custom Mount Config can boost flexibility. It ships a default mount config which you can use, but to manage multiple modules and import without adding too many boilerplate codes, it is recommended to have a custom mount config for specific instances. ` Cypress Intercept Component testing handles the individual components you are testing at a particular time, to access external API it is recommended to use cy.intercept. According to the Doc Cy.intercept can be used to passively listen for matching routes without manipulating the request or its response in any way. ` Use createOutputSpy When working with eventEmitter for components that may contain forms or other elements with events, createOutputSpy will automatically create an EventEmitter and set up the spy on it's .emit() method. ` Jordan Powell’s Advanced Cypress Patterns Session When testing for routes or components that require authentication Cypress provides cy.session which eliminates creating functions in your test to check for sessions on every call to the route or component. cy.session caches the sessions, and it will skip the login process for testing components that need the sessions on a second call. ` Origin Running tests for projects that require a visit to multiple different domains could get CORS, or a limitation of visits, due to browser environment. Cypress provides Origin to help bypass some of the browser limitations. ` Conclusion In this article, we looked at Jordan Powell’s tips for writing End-to-end tests, component tests, and advanced testing patterns in Cypress. I recommend watching the full video for Jordan Powell’s Advanced Cypress JS Drop training. Are you excited about the Cypress Component Testing? Let us know on Twitter....

Dec 19, 2022

6 mins

CypressTesting

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh

In this episode of Leadership Exchange, host Rob Ocel chats with Jerry Reghunadh, Senior Director of Enterprise Architecture at Data Nimbus, about leadership, AI adoption, and data-driven decision-making. Jerry shares his career journey, insights on leveraging tools like ChatGPT and Copilot, and strategies for building effective data pipelines. They explore how companies can avoid "analysis paralysis," adopt AI strategically, and evaluate new technologies to solve real-world problems. Tune in for practical advice on aligning innovation with business goals and staying competitive in a rapidly evolving tech landscape. Chapters 00:00 – Introduction 00:31 – Jerry’s Leadership Journey 02:01 – Discussing AI in Leadership 03:59 – Experimenting with AI Tools 06:24 – Overcoming Analysis Paralysis 09:18 – Importance of Early AI Adoption 13:12 – AI’s Impact on Efficiency 14:30 – Sponsor Message 16:26 – Setting Realistic Goals for AI 19:41 – Data Management and AI 23:09 – Is AI Just a Fad? 27:22 – Testing New Technologies 29:56 – Final Thoughts on AI 30:25 – Connect with Jerry 30:44 – Closing Remarks 31:20 – Outro Follow Jerry on Social Media Linkedin: https://www.linkedin.com/in/jerrymannel/ Sponsored by This Dot: thisdot.co...

Nov 18, 2024

1 min

AIEngineering Leadership

Let's innovate together!

We're ready to be your trusted technical partners in your digital innovation journey.

Whether it's modernization or custom software solutions, our team of experts can guide you through best practices and how to build scalable, performant software that lasts.

How to Build Apps with Great Startup Performance Using Qwik

Table of Contents

What is Qwik?

How to create a Counter Component in Qwik

Unique features of Qwik

Directory Based Routing

Slots in Qwik

Very little JavaScript in production

Resumability with Qwik

Hassan Sani

You might also like

The Journey To Making A New Framework: TanStack Start with Tanner Linsley

Exploring Angular Forms: A New Alternative with Signals

How to Create Better Test Coverage Using Cypress 10

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh

Let's innovate together!

You might also like

The Journey To Making A New Framework: TanStack Start with Tanner Linsley

Exploring Angular Forms: A New Alternative with Signals

How to Create Better Test Coverage Using Cypress 10

AI Leadership: Data-Driven Decision Making & Avoiding "Analysis Paralysis" with Jerry Reghunadh