VueJS

Layouts & Theming in Vuetify 3

Published May 19, 2023

Updated Oct 12, 2023

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This article was written over 18 months ago and may contain information that is out of date.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

Introduction

Do you want to avoid tinkering with CSS to get your website looking just right?

Branding is everything in today's digital landscape. With Vuetify 3's customizable theming options, you can create web projects that perfectly reflect your unique branding, and visual identity. Additionally, you can reduce the duplicated code by creating layouts representing your application's different page structures.

In a previous article introducing Vuetify 3 with Vue 3, we created an application that allowed us to add, display, and delete jokes. If you'd like to follow along with this article, please clone the GitHub repository.

git clone https://github.com/thisdot/blog-demos.git
# or `git@github.com:thisdot/blog-demos.git` for ssh

# then cd into the project directory
cd layouts-and-theming-in-vueityf

In this article, we'll go over how you can create layouts in Vuetify 3 to allow you to reuse the same layout for pages that share the same structure. We will also go over how you can customize the look and feel of your application to match your brand's visual identity through the powerful theming tools that Vuetify 3 offers us.

Layouts in Vuetify 3

What are layouts, and how are they useful?

In web development, layouts are akin to blueprints for the structure of your web pages. They provide a consistent and reusable frame for the different pages of an application. A well-designed layout can improve the user experience by providing familiarity and predictability as the user navigates through other parts of your application.

Layouts are particularly helpful in reducing code duplication. Instead of defining the same structure for each page—headers, footers, and navigation menus, you define them once in a layout, and then apply that layout to any page that uses the same structure. This speeds up development, and makes your code easier to maintain.

Using Layouts in Vuetify 3

Creating a layout in Vuetify 3 is as simple as creating a new Vue component. This component will include the common elements shared across multiple pages like headers, footers, and navigation bars. Here is an example of a basic layout:

<template>
  <v-app>
    <v-main>
      <v-header> ... </v-header>
      <v-navigation-drawer> ... </v-navigation-drawer>
      <router-view/>
    </v-main>
    <v-footer> ... </v-footer>
  </v-app>
</template>

This layout has a header, a navigation drawer, and a footer. The <router-view/> component is where the content of the specific pages will be injected.

Building a layout for our application

Let's create a layout for our application. We'll have a top navigation bar and a footer. Inside the layouts directory, create a new file named Default.vue and add the following code:

<template>
  <v-app>
    <v-app-bar app color="primary" dark>
      <v-toolbar-title>Joke Machine</v-toolbar-title>
    </v-app-bar>

    <v-main>
      <router-view/>
    </v-main>

    <v-footer color="primary" app>
      <span>&copy; 2023 Joke Machine</span>
    </v-footer>
  </v-app>
</template>

Additionally, in order for us to use our layout, we will need to modify our router/index.ts file to use the Default.vue component:

const routes = [
{
    //...
    component: () => import('@/layouts/Default.vue'),
    //...
}

This will make sure that our respective pages use the Default.vue layout that we created. The contents of the pages will appear in place of <router-view> in the layout.

It is also worth noting that you can create, and nest as many layouts as you want.

Theming in Vuetify 3

Themes allow you to customize your application's default colors, surfaces, and more. If your brand has specific colors and styling, you can theme your Vuetify application to resemble your brand through theming better. Additionally, Vuetify 3 allows you to modify your theme in real-time programmatically. [Vuetify 3] also comes with light and dark themes pre-installed.

Theming API

Vuetify 3 offers us 2 main APIs for working with themes:

useTheme is a composable that allows us to get information about the current theme and will enable us to modify the existing theme.
v-theme-provider is used in the <template> section of your Vue files to modify the theme of all of its children.

Updating the theme of our application

Updating the theme of our application is straightforward with Vuetify 3. Let's customize our application's primary and secondary colors. In the vuetify.ts file, modify the themes section to contain the following styles:

import { createVuetify } from 'vuetify'
import 'vuetify/styles'

const vuetify = createVuetify({
  theme: {
    themes: {
      light: {
        background: '#FFFFFF',
        surface: '#F2F5F8',
        primary: '#6200EE',
        secondary: '#03DAC6',
        error: '#B00020',
        info: '#2196F3',
        success: '#4CAF50',
        warning: '#FB8C00',
      },
    },
  },
})

In this example, we're defining a custom 'light' theme. If you want to use a dark theme, or any other named theme, you can add those as additional properties within the themes object. For example:

themes: {
  light: { /* ... */ },
  dark: { /* ... */ },
}

And... That's it! By changing the various config options in the vuetify.ts file, you can modify how your application looks and feels to match your brand. If you'd like to learn more about themes and all the options you can provide, please check out the official Vuetify documentation.

Conclusion

In this article, we've gone through the concepts of layouts and theming in Vuetify 3. We've seen how layouts can reduce code duplication, and provide consistency across your application. We've looked at how Vuetify's theming features allow you to customize your application to match your brand's visual identity.

Understanding and utilizing these features effectively can significantly enhance the development experience and the end user's interaction with your application. Remember, a well-structured and visually appealing application not only attracts users, but also retains them. Happy coding!

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)

Allan M. Jeremy
Allan Jeremy is a self-proclaimed polymath, entrepreneur and Senior Software Engineer at ThisDot Labs. He is an AI and crypto enthusiast that loves to learn most things tech and business as well as sharing what he learns.
@theallanjeremy @AllanJeremy

Understanding Vue.js's <Suspense> and Async Components

In this blog post, we will delve into how and async components work, their benefits, and practical implementation strategies to make your Vue.js applications more efficient and user-friendly. Without further ado, let’s get started! Suspense Let's kick off by explaining what Suspense components are. They are a new component that helps manage how your application handles components that need to await for some async resource to resolve, like fetching data from a server, waiting for images to load, or any other task that might take some time to complete before they can be properly rendered. Imagine you're building a web page that needs to load data from a server, and you have 2 components that fetch the data you need as they will show different things. Typically, you might see a loading spinner or a skeleton while the data is being fetched. Suspense components make it easier to handle these scenarios. Instead of manually managing loading states and error messages for each component that needs to fetch data, Suspense components let you wrap all these components together. Inside this wrapper, you can define: 1. What to show while the data is loading (like a loading spinner). 2. The actual content that should be displayed once the data is successfully fetched. This way, Vue Suspense simplifies the process of handling asynchronous operations (like data fetching) and improves the user (and the developer) experience by providing a more seamless and integrated way to show loading states and handle errors. There are two types of async dependencies that can wait on: - Components with an async setup() hook. This includes components using with top-level await expressions. *Note: These can only be used within a component.* - Async Components. Async components Vue's asynchronous components are like a smart loading system for your web app. Imagine your app as a big puzzle. Normally, you'd put together all the pieces at once, which can take time. But what if some pieces aren't needed right away? Asynchronous components help with this. Here's how they work: - Load Only What's Needed: Just like only picking up puzzle pieces you need right now, asynchronous components let your app load only the parts that are immediately necessary. Other parts can be loaded later, as needed. - Faster Start: Your app starts up faster because it doesn't have to load everything at once. It's like quickly starting with the border of a puzzle and filling in the rest later. - Save Resources: It uses your web resources (like internet data) more wisely, only grabbing what’s essential when it's essential. In short, asynchronous components make your app quicker to start and more efficient, improving the overall experience for your users. Example: ` Combining Async Components and Suspense Let's explore how combining asynchronous components with Vue's Suspense feature can enhance your application. When asynchronous components are used with Vue's Suspense, they form a powerful combination. The key point is that async components are "suspensable" by default. This means they can be easily integrated with Suspense to improve how your app handles loading and rendering components. When used together, you can do the following things: - Centralized Loading and Error Handling: With Suspense, you don't have to handle loading and error states individually for each async component. Instead, you can define a single loading indicator or error message within the Suspense component. This unified approach simplifies your code and ensures consistency across different parts of your app. - Flexible and Clean Code Structure: By combining async components with Suspense, your code becomes more organized and easier to maintain. An asynchronous component has the flexibility to operate independently of Suspense's oversight. By setting suspensible: false in its options, the component takes charge of its own loading behavior. This means that instead of relying on Suspense to manage when it appears, the component itself dictates its loading state and presentation. This option is particularly useful for components that have specific loading logic or visuals they need to maintain, separate from the broader Suspense-driven loading strategy in the application. In practice, this combo allows you to create a user interface that feels responsive and cohesive. Users see a well-timed loading indicator while the necessary components are being fetched, and if something goes wrong, a single, well-crafted error message is displayed. It's like ensuring that the entire puzzle is either revealed in its completed form or not at all rather than showing disjointed parts at different times. How it works When a component inside the boundary is waiting for something asynchronous, shows fallback content. This fallback content can be anything you choose, such as a loading spinner or a message indicating that data is being loaded. Example Usage Let’s use a simple example: In the visual example provided, imagine we have two Vue components: one showcasing a selected Pokémon, Eevee, and a carousel showcasing a variety of other Pokémon. Both components are designed to fetch data asynchronously. Without , while the data is being fetched, we would typically see two separate loading indicators: one for the Eevee Pokemon that is selected and another for the carousel. This can make the page look disjointed and be a less-than-ideal user experience. We could display a single, cohesive loading indicator by wrapping both components inside a boundary. This unified loading state would persist until all the data for both components—the single Pokémon display and the carousel—has been fetched and is ready to be rendered. Here's how you might structure the code for such a scenario: ` Here, is the component that's performing asynchronous operations. While loading, the text 'Loading...' is displayed to the user. Great! But what about when things don't go as planned and an error occurs? Currently, Vue's doesn't directly handle errors within its boundary. However, there's a neat workaround. You can use the onErrorCaptured() hook in the parent component of to catch and manage errors. Here's how it works: ` If we run this code, and let’s say that we had an error selecting our Pokemon, this is how it is going to display to the user: The error message is specifically tied to the component where the issue occurred, ensuring that it's the only part of your application that shows an error notification. Meanwhile, the rest of your components will continue to operate and display as intended, maintaining the overall user experience without widespread disruption. This targeted error handling keeps the application's functionality intact while indicating where the problem lies. Conclusion stands out as a formidable feature in Vue.js, transforming the management of asynchronous operations into a more streamlined and user-centric process. It not only elevates the user experience by ensuring smoother interactions during data loading phases but also enhances code maintainability and application performance. I hope you found this blog post enlightening and that it adds value to your Vue.js projects. As always, happy coding and continue to explore the vast possibilities Vue.js offers to make your applications more efficient and engaging!...

Apr 24, 2024

6 mins

VueWeb PerformanceUXJavaScript

Understanding Vue's Reactive Data

Introduction Web development has always been about creating dynamic experiences. One of the biggest challenges developers face is managing how data changes over time and reflecting these changes in the UI promptly and accurately. This is where Vue.js, one of the most popular JavaScript frameworks, excels with its powerful reactive data system. In this article, we dig into the heart of Vue's reactivity system. We unravel how it perfectly syncs your application UI with the underlying data state, allowing for a seamless user experience. Whether new to Vue or looking to deepen your understanding, this guide will provide a clear and concise overview of Vue's reactivity, empowering you to build more efficient and responsive Vue 3 applications. So, let’s kick off and embark on this journey to decode Vue's reactive data system. What is Vue's Reactive Data? What does it mean for data to be ”'reactive”? In essence, when data is reactive, it means that every time the data changes, all parts of the UI that rely on this data automatically update to reflect these changes. This ensures that the user is always looking at the most current state of the application. At its core, Vue's Reactive Data is like a superpower for your application data. Think of it like a mirror - whatever changes you make in your data, the user interface (UI) reflects these changes instantly, like a mirror reflecting your image. This automatic update feature is what we refer to as “reactivity”. To visualize this concept, let's use an example of a simple Vue application displaying a message on the screen: ` In this application, 'message' is a piece of data that says 'Hello Vue!'. Let's say you change this message to 'Goodbye Vue!' later in your code, like when a button is clicked. ` With Vue's reactivity, when you change your data, the UI automatically updates to 'Goodbye Vue!' instead of 'Hello Vue!'. You don't have to write extra code to make this update happen - Vue's Reactive Data system takes care of it. How does it work? Let's keep the mirror example going. Vue's Reactive Data is the mirror that reflects your data changes in the UI. But how does this mirror know when and what to reflect? That's where Vue's underlying mechanism comes into play. Vue has a behind-the-scenes mechanism that helps it stay alerted to any changes in your data. When you create a reactive data object, Vue doesn't just leave it as it is. Instead, it sends this data object through a transformation process and wraps it up in a Proxy. Proxy objects are powerful and can detect when a property is changed, updated, or deleted. Let's use our previous example: ` Consider our “message” data as a book in a library. Vue places this book (our data) within a special book cover (the Proxy). This book cover is unique - it's embedded with a tracking device that notifies Vue every time someone reads the book (accesses the data) or annotates a page (changes the data). In our example, the reactive function creates a Proxy object that wraps around our state object. When you change the 'message': ` The Proxy notices this (like a built-in alarm going off) and alerts Vue that something has changed. Vue then updates the UI to reflect this change. Let’s look deeper into what Vue is doing for us and how it transforms our object into a Proxy object. You don't have to worry about creating or managing the Proxy; Vue handles everything. ` In the example above, we encapsulate our object, in this case, “state”, converting it into a Proxy object. Note that within the second argument of the Proxy, we have two methods: a getter and a setter. The getter method is straightforward: it merely returns the value, which in this instance is “state.message” equating to 'Hello Vue!' Meanwhile, the setter method comes into play when a new value is assigned, as in the case of “state.message = ‘Hey young padawan!’”. Here, “value” becomes our new 'Hey young padawan!', prompting the property to update. This action, in turn, triggers the reactivity system, which subsequently updates the DOM. Venturing Further into the Depths If you have been paying attention to our examples above, you might have noticed that inside the Proxy method, we call the functions track and trigger to run our reactivity. Let’s try to understand a bit more about them. You see, Vue 3 reactivity data is more about Proxy objects. Let’s create a new example: ` In this example, when you click on the button, the message's value changes. This change triggers the effect function to run, as it's actively listening for any changes in its dependencies. How does the effect property know when to be called? Vue 3 has three main functions to run our reactivity: effect, track, and trigger. The effect function is like our supervisor. It steps in and takes action when our data changes – similar to our effect method, we will dive in more later. Next, we have the track function. It notes down all the important data we need to keep an eye on. In our case, this data would be state.message. Lastly, we've got the trigger function. This one is like our alarm bell. It alerts the effect function whenever our important data (the stuff track is keeping an eye on) changes. In this way, trigger, track, and effect work together to keep our Vue application reacting smoothly to changes in data. Let’s go back to them: ` Tracking (Dependency Collection) Tracking is the process of registering dependencies between reactive objects and the effects that depend on them. When a reactive property is read, it's "tracked" as a dependency of the current running effect. When we execute track(), we essentially store our effects in a Set object. But what exactly is an "effect"? If we revisit our previous example, we see that the effect method must be run whenever any property changes. This action — running the effect method in response to property changes — is what we refer to as an "Effect"! (computed property, watcher, etc.) > Note: We'll outline a basic, high-level overview of what might happen under the hood. Please note that the actual implementation is more complex and optimized, but this should give you an idea of how it works. Let’s see how it works! In our example, we have the following reactive object: ` We need a way to reference the reactive object with its effects. For that, we use a WeakMap. Which type is going to look something like this: ` We are using a WeakMap to set our object state as the target (or key). In the Vue code, they call this object targetMap. Within this targetMap object, our value is an object named depMap of Map type. Here, the keys represent our properties (in our case, that would be message and showSword), and the values correspond to their effects – remember, they are stored in a Set that in Vue 3 we refer to as dep. Huh… It might seem a bit complex, right? Let's make it more straightforward with a visual example: With the above explained, let’s see what this Track method kind of looks like and how it uses this targetMap. This method essentially is doing something like this: ` At this point, you have to be wondering, how does Vue 3 know what activeEffect should run? Vue 3 keeps track of the currently running effect by using a global variable. When an effect is executed, Vue temporarily stores a reference to it in this global variable, allowing the track function to access the currently running effect and associate it with the accessed reactive property. This global variable is called inside Vue as activeEffect. Vue 3 knows which effect is assigned to this global variable by wrapping the effects functions in a method that invokes the effect whenever a dependency changes. And yes, you guessed, that method is our effect method. ` This method behind the scenes is doing something similar to this: ` The handling of activeEffect within Vue's reactivity system is a dance of careful timing, scoping, and context preservation. Let’s go step by step on how this is working all together. When we run our Effect method for the first time, we call the get trap of the Proxy. ` When running the get trap, we have our activeEffect so we can store it as a dependency. ` This coordination ensures that when a reactive property is accessed within an effect, the track function knows which effect is responsible for that access. Trigger Method Our last method makes this Reactive system to be complete. The trigger method looks up the dependencies for the given target and key and re-runs all dependent effects. ` Conclusion Diving into Vue 3's reactivity system has been like unlocking a hidden superpower in my web development toolkit, and honestly, I've had a blast learning about it. From the rudimentary elements of reactive data and instantaneous UI updates to the intricate details involving Proxies, track and trigger functions, and effects, Vue 3's reactivity is an impressively robust framework for building dynamic and responsive applications. In our journey through Vue 3's reactivity, we've uncovered how this framework ensures real-time and precise updates to the UI. We've delved into the use of Proxies to intercept and monitor variable changes and dissected the roles of track and trigger functions, along with the 'effect' method, in facilitating seamless UI updates. Along the way, we've also discovered how Vue ingeniously manages data dependencies through sophisticated data structures like WeakMaps and Sets, offering us a glimpse into its efficient approach to change detection and UI rendering. Whether you're just starting with Vue 3 or an experienced developer looking to level up, understanding this reactivity system is a game-changer. It doesn't just streamline the development process; it enables you to create more interactive, scalable, and maintainable applications. I love Vue 3, and mastering its reactivity system has been enlightening and fun. Thanks for reading, and as always, happy coding!...

Nov 22, 2023

7 mins

VueJavaScriptTypeScriptWeb Development

Improving the Performance of Vue 3 Applications Using v-memo and KeepAlive

Introduction When building a Vue application, you will encounter performance issues as your app grows, causing it to run slower than it should. Most performance problems in web apps arise from performing tasks repeatedly, even when there is no need to. For example, if you had a list of thousands of items, and had to re-render all items when a single thing changed, you'd quickly encounter performance problems. The ideal solution would be to update only what changes. For the most part, VueJS does this well, and Vue 3 came with many performance improvements out of the box. However, in more complex applications, we may need more fine-grained control over what gets re-rendered and what does not. In this article, we are going to look at how we can use v-memo, and KeepAlive as solutions to performance problems in Vue applications. Two leading solutions to performance problems in Vue JS Memoization Memoization is like a superpower that helps your app remember things without having to constantly redo the same calculations, or processes over and over again. This allows the applications to perform faster and more efficiently, which is the ultimate goal for any web developer. Think about it; when you were a kid, your teachers always taught you to memorize things to save time. The same is valid for web applications. With memoization, they can remember the results of a calculation or process, so they don't have to waste time recalculating it every time they need the same result. For example, imagine you have a website that requires users to enter their birthdates to access certain content. If a user enters their birthdate for the first time, the application will calculate their age. With memoization, the next time the user comes to the website and enters their birthdate, the application can use the previously computed result instead of recalculating it from scratch. That's the beauty of memoization! It saves time and resources, and gives the user a faster and smoother experience. Try memoization if you want your web application to perform at its best. You'll be amazed at how much of a difference it makes! To take advantage of this in Vue, we'll be using the v-memo directive. More on this shortly. Caching Caching works by storing a copy of frequently used data and resources so that the application can access them quickly without having to go through the entire process of rendering and fetching the data from scratch. Think of it like this. When you visit a website for the first time, the browser has to fetch all the resources needed to display the page. But if you see the same website again, the browser can use the cached data, resulting in a faster and smoother experience for the user. We can take advantage of caching in our Vue applications using KeepAlive. Using v-memo V-memo was added in Vue 3.2 and, as far as I am aware, will not be back-ported to Vue 2. You can use v-memo by passing the directive to the element/component whose dependencies you want to memoize. In this case, this would be an element/component that would be computationally expensive to re-render each time a dependency changed. Here's an example of how you could use the v-memo directive: ` Note that it accepts an array of dependency values. And if every value in the array is the same as the last render, updates for the entire sub-tree will be skipped. The dependency values are those that's changes you'd like to be checked and memoized anytime they change. You can learn more about how v-memo works from the official Vue JS documentation. In this case, if the value of dependencyA or dependencyB changed, we would re-render the children of the div. However, if neither dependencyA nor dependencyB changed, we would skip the re-rendering process. This means that any computationally intensive tasks that were needed to occur in the re-render would not be triggered, and as a result, our application would perform better. Using KeepAlive Another alternative solution to performance issues is caching, where the KeepAlive option comes in. KeepAlive is a built-in vue component that allows us to cache component instances when dynamically switching between multiple components conditionally. Using KeepAlive in Vue 3 is straightforward. You can wrap the components you want to cache inside a KeepAlive component. Here's a sample code: ` In this example, we use the KeepAlive component to conditionally cache the ComponentA and ComponentB instances, which are dynamically switched using the currentComponent reactive property. With the KeepAlive component, we can maintain the state of these components even when they are not active, which can lead to improved performance. Conclusion In this article, we talked about how we can improve the performance of our VueJS applications using memoization and caching. In the case of memoization, we can use the v-memo VueJS directive that was introduced in Vue 3.2. Alternatively, when we want to cache component instances, we can use the built-in Vue KeepAlive component. By utilizing both v-memo and KeepAlive, you can optimize the performance of your Vue 3 applications, resulting in faster and smoother user experiences. That being said, if you are looking to start a new Vue JS project and need help with how to structure your project, feel free to check out our Vue JS starter.dev GitHub showcases, which showcase (no kidding) a mini-GitHub clone application built using Vue in different ways (e.g., using Nuxt, Quasar], Vite, etc.). Alternatively, if you are looking to start a new project without worrying about all the config required, you can check out the [Vue JS starter kit instead. Thanks for checking this out!...

Feb 24, 2023

4 mins

Vue

Introduction to Zod for Data Validation

As web developers, we're often working with data from external sources like APIs we don't control or user inputs submitted to our backends. We can't always rely on this data to take the form we expect, and we can encounter unexpected errors when it deviates from expectations. But with the Zod library, we can define what our data ought to look like and parse the incoming data against those defined schemas. This lets us work with that data confidently, or to quickly throw an error when it isn't correct. Why use Zod? TypeScript is great for letting us define the shape of our data in our code. It helps us write more correct code the first time around by warning us if we are doing something we shouldn't. But TypeScript can't do everything for us. For example, we can define a variable as a string or a number, but we can't say "a string that starts with user_id_ and is 20 characters long" or "an integer between 1 and 5". There are limits to how much TypeScript can narrow down our data for us. Also, TypeScript is a tool for us developers. When we compile our code, our types are not available to the vanilla JavaScript. JavaScript can't validate that the data we actually use in our code matches what we thought we'd get when we wrote our TypeScript types unless you're willing to manually write code to perform those checks. This is where we can reach for a tool like Zod. With Zod, we can write data schemas. These schemas, in the simplest scenarios, look very much like TypeScript types. But we can do more with Zod than we can with TypeScript alone. Zod schemas let us create additional rules for data parsing and validation. A 20-character string that starts with user_id_? It's z.string().startsWith('user_id_').length(20). An integer between 1 and 5 inclusive? It's z.number().int().gte(1).lte(5). Zod's primitives give us many extra functions to be more specific about *exactly* what data we expect. Unlike TypeScript, Zod schemas aren't removed on compilation to JavaScript—we still have access to them! If our app receives some data, we can verify that it matches the expected shape by passing it to your Zod schema's parse function. You'll either get back your data in exactly the shape you defined in your schema, or Zod will give you an error to tell you what was wrong. Zod schemas aren't a replacement for TypeScript; rather, they are an excellent complement. Once we've defined our Zod schema, it's simple to derive a TypeScript type from it and to use that type as we normally would. But when we really need to be sure our data conforms to the schema, we can always parse the data with our schema for that extra confidence. Defining Data Schemas Zod schemas are the variables that define our expectations for the shape of our data, validate those expectations, and transform the data if necessary to match our desired shape. It's easy to start with simple schemas, and to add complexity as required. Zod provides different functions that represent data structures and related validation options, which can be combined to create larger schemas. In many cases, you'll probably be building a schema for a data object with properties of some primitive type. For example, here's a schema that would validate a JavaScript object representing an order for a pizza: ` Zod provides a number of primitives for defining schemas that line up with JavaScript primitives: string, number, bigint, boolean, date, symbol, undefined, and null. It also includes primitives void, any, unknown, and never for additional typing information. In addition to basic primitives, Zod can define object, array, and other native data structure schemas, as well as schemas for data structures not natively part of JavaScript like tuple and enum. The documentation contains considerable detail on the available data structures and how to use them. Parsing and Validating Data with Schemas With Zod schemas, you're not only telling your program what data should look like; you're also creating the tools to easily verify that the incoming data matches the schema definitions. This is where Zod really shines, as it greatly simplifies the process of validating data like user inputs or third party API responses. Let's say you're writing a website form to register new users. At a minimum, you'll need to make sure the new user's email address is a valid email address. For a password, we'll ask for something at least 8 characters long and including one letter, one number, and one special character. (Yes, this is not really the best way to write strong passwords; but for the sake of showing off how Zod works, we're going with it.) We'll also ask the user to confirm their password by typing it twice. First, let's create a Zod schema to model these inputs: ` So far, this schema is pretty basic. It's only making sure that whatever the user types as an email is an email, and it's checking that the password is at least 8 characters long. But it is *not* checking if password and confirmPassword match, nor checking for the complexity requirements. Let's enhance our schema to fix that! ` By adding refine with a custom validation function, we have been able to verify that the passwords match. If they don't, parsing will give us an error to let us know that the data was invalid. We can also chain refine functions to add checks for our password complexity rules: ` Here we've chained multiple refine functions. You could alternatively use superRefine, which gives you even more fine grained control. Now that we've built out our schema and added refinements for extra validation, we can parse some user inputs. Let's see two test cases: one that's bound to fail, and one that will succeed. ` There are two main ways we can use our schema to validate our data: parse and safeParse. The main difference is that parse will throw an error if validation fails, while safeParse will return an object with a success property of either true or false, and either a data property with your parsed data or an error property with the details of a ZodError explaining why the parsing failed. In the case of our example data, userInput2 will parse just fine and return the data for you to use. But userInput1 will create a ZodError listing all of the ways it has failed validation. ` ` We can use these error messages to communicate to the user how they need to fix their form inputs if validation fails. Each error in the list describes the validation failure and gives us a human readable message to go with it. You'll notice that the validation errors for checking for a valid email and for checking password length have a lot of details, but we've got three items at the end of the error list that don't really tell us anything useful: just a custom error of Invalid input. The first is from our refine checking if the passwords match, and the second two are from our refine functions checking for password complexity (numbers and special characters). Let's modify our refine functions so that these errors are useful! We'll add our own error parameters to customize the message we get back and the path to the data that failed validation. ` Now, our error messages from failures in refine are informative! You can figure out which form fields aren't validating from the path, and then display the messages next to form fields to let the user know how to remedy the error. ` By giving our refine checks a custom path and message, we can make better use of the returned errors. In this case, we can highlight specific problem form fields for the user and give them the message about what is wrong. Integrating with TypeScript Integrating Zod with TypeScript is very easy. Using z.infer<typeof YourSchema> will allow you to avoid writing extra TypeScript types that merely reflect the intent of your Zod schemas. You can create a type from any Zod schema like so: ` Using a TypeScript type derived from a Zod schema does *not* give you any extra level of data validation at the type level beyond what TypeScript is capable of. If you create a type from z.string.min(3).max(20), the TypeScript type will still just be string. And when compiled to JavaScript, even that will be gone! That's why you still need to use parse/safeParse on incoming data to validate it before proceeding as if it really does match your requirements. A common pattern with inferring types from Zod schemas is to use the same name for both. Because the schema is a variable, there's no name conflict if the type uses the same name. However, I find that this can lead to confusing situations when trying to import one or the other—my personal preference is to name the Zod schema with Schema at the end to make it clear which is which. Conclusion Zod is an excellent tool for easily and confidently asserting that the data you're working with is exactly the sort of data you were expecting. It gives us the ability to assert at runtime that we've got what we wanted, and allows us to then craft strategies to handle what happens if that data is wrong. Combined with the ability to infer TypeScript types from Zod schemas, it lets us write and run more reliable code with greater confidence....

Nov 15, 2024

7 mins

JavaScriptZod

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Layouts & Theming in Vuetify 3

Introduction

Layouts in Vuetify 3

What are layouts, and how are they useful?

Using Layouts in Vuetify 3

Building a layout for our application

Theming in Vuetify 3

Theming API

Updating the theme of our application

Conclusion

Allan M. Jeremy

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