From a javascript library to a framework, Vue's journey is impressive, especially when you consider how it still maintains its lightweight nature. There are several features that Vue3 offers, including Pinia, which enables easier state management, as well as a build toolchain that works on Vite. Whether you want to update your apps to Vue3 or simply want to experiment with the framework, we have compiled everything that you need to know about Vue3 here!

What is Vue3?

Before we get into the changes that you will see in Vue3, let's first take a look at what Vue.js and its core components are:

Vue

Vue.js is an open-source front-end JavaScript framework that can be used to create user interfaces. The framework offers a declarative and component-based coding approach that aids in the speedy development of user displays. It can be used to develop basic or complicated interfaces and is built on top of industry-standard HTML, CSS, and JavaScript. The reasons for Vue.js's popularity and large user base of Vue.js is its programmer-friendly syntax, ease of use, and well-defined documentation.

vue

As mentioned above, Vue.js is built on two core characteristics:

Declarative rendering enables the user to define HTML output declaratively depending on the JavaScript state. Vue.js expands on normal HTML with the help of template syntax.

Reactivity - Vue.js actively monitors the JavaScript state, and when it gets modified, it quickly refreshes the DOM.

Vue3.0

Engineers who are using Vue 2 to code now need to update to Vue3. This is because it has new capabilities that make designing readable, consistent components much easier and better methods to organize our applications. Vue3 is more user-friendly, shorter, and simpler to maintain. Some of the notable features of Vue3 are Teleport, Fragments, and multiple v-models.

The latest version also got rid of the filters and has state-driven CSS variables as well as an experimental suspense feature. It also has lifecycle naming modifications and single file component alterations.

Has Vue3 been released?

The latest version of Vue available - Vue3, was initially announced in mid-2018 and officially released in September 2020. Vue3.0 was declared as the official default version of the progressive javascript framework on 7th February 2022.

What's new in Vue3?

The most exciting changes to look forward to in Vue3 are:

Provide/inject

Vue 2 allowed users to pass data such as strings, arrays, objects, and more through props in code. Such data could be easily passed from a parent element to its child elements. However, using props made it more challenging to send data from the parent element to a deeply nested child element. As a result, developers had to use the Vuex Store and Event Hub. Vue 2.2.0 also included provide/inject, but it was not advised to be used in the general program code.

However, by using the improved provide/inject combo in Vue3, we can pass data more quickly and neatly. As the name suggests, we utilize to provide to make data accessible from a parent element to any of its child components, irrespective of how deeply nested those child elements are. Here, we can use provide as objects or as functions.

Teleport

Based on the logic of the app you want to build, your components may be shown in places that are different from where you want them displayed. For example, you may want to create a popup that is intended to appear and take up the entire screen. To overcome this, we can use the position attribute of such components in CSS, but with Vue3, developers can also use Teleport.

Teleport lets programmers take an element from its initial container that it is wrapped in and move them to any already existing component on the page where they are in use. For example, you can relocate a header element from the #app div to the header. Remember that you can only use Teleport to move elements to components of code that exist outside of the Vue DOM.

Fragments

It is difficult to have several root components in a file's template in Vue 2. Programmers began enclosing all components in a parent component as a solution for the same. Sometimes, programmers may need to render an element without a container wrapped around it.Engineers can now have numerous items in their root template file thanks to Fragments, which is a feature added to Vue3.

Global Vue API

You could have frequently found the Vue.component or Vue.use in the main.js file of a Vue app. They are referred to as Global APIs, and there are many such methods in Vue 2. Here if you have multiple instances of your app, all of them are placed atop Vue. It is difficult to limit specific functionality to a single application instance.

Vue3 solves this problem by introducing a new Global API called createApp. With this method, you can get a fresh instance of a Vue application. All Vue 2.x-related APIs will be transferred to separate app instances. This allows every instance of your application to have functions that are exclusive to it without disrupting other instances that are already in use.

Events API

In addition to using the Vuex Store, the use of Event Bus is one of the most popular methods programmers have used for passing data between elements that do not share a parent-child context. However, codes such as $on, $off, and $once were all deleted in Vue3. But $emit is still accessible as child elements must emit events to their parent elements. A solution to this would be to use provide/inject.

Vite-powered build toolchain

Designed by Evan You, the creator of Vue, Vite is a top-notch Vue SFC support toolchain that is lightweight and quick to create. Vite is now the engine behind the standard Vue3 build configuration. The module bundler @vue-cli/service, which is built on top of webpack, will wrap your whole Vue application on launch, hot reloads, and compilation. Vite, on the other hand, will take the ES Import syntax from your program code and allow the browser to analyze each import before sending an HTTP request.

Evan You

The change is being made primarily for reasons of speed. The server starts immediately since it employs native browser support for JavaScript components and is much faster.

Composition API syntax

The Options API was used for creating element states and logic. The Composition API was launched by Vue3 as a substitute for the same. It is merely a collection of APIs that enables us to create Vue elements without defining options by using imported methods.

The Composition API contains the following APIs:

Reactivity API - For example, ref() and reactive(). It can directly build reactive state, calculated state, and watchers using this.

Lifecycle hooks - For example, onMounted() and onUnmounted(). We can hook into the element lifecycle using lifecycle hooks.

Dependency injection - For example, provide() and inject(). Utilizing Vue's dependency injection system with Reactivity APIs is made possible by dependency injection.

Pros of using composition APIs

The main advantages of using Composition APIs over the Options API are:

  • An element is no longer necessary with Vue3 to generate a reactive state.
  • When adding numerous reactive attributes, setup in Vue.js elements can become bloated. It could be useful to have these reactive variables abstracted in separate javascript files because of this.
  • The main benefit of the Composition API is that it makes it possible to reuse clear, effective logic in the shape of Composable methods. It addresses all of the issues with mixins, the main method of reusing logic in the Options API.
  • You can type code in the Composition API with complete type inference.
  • The programs you write in the Composition API are more efficient, and the names of the variables can be made smaller. This reduces the overhead.
  • You can share your program code better with Composition API.

Pinia

Pinia is a lightweight state management tool for Vue.js. It enables us to share a state between elements and pages. It creates a user-friendly, completely typed state management framework using the new reactivity concept in Vue3. This is now Vue3's new standard state control library.

Pinia initially served as a study into the potential of Vuex. For a long time, Vuex was the suggested state management system for Vue, but with Vue3, Pinia is the recommended system for managing states in the official documentation. Currently, Vuex is in maintenance mode. Although it continues to function, no new features will be added. Use of Pinia is advised for fresh apps.

Why Pinia?

Pinia is very lightweight, coming up to only 1KB. Additionally, it integrates with the Vue.js dev tools to improve your coding experience in Vue 2 and Vue3. Since Pinia infers all of your datatypes, it can offer you complete and precise auto completion in javascript as well. Pinia is also modular by design, user-friendly, and expandable. Overall, Pinia appears to be lightweight, uncomplicated, and straightforward. It closely resembles dealing with elements and contains all the tools necessary for dynamic programming in Vue3.

Will Vue 2 be deprecated?

The last minor update for Vue 2 was Vue 2.7, which was released in July 2022. Vue 2 is currently in maintenance mode. While no additional features will be shipped, it will still get crucial bug fixes and security patches for 18 months. By the end of 2023, Vue 2 will be deprecated.

Migration from Vue 2

Based on your software, switching to Vue3 may not be worthwhile if you are working on an extremely large project using Vue 2. Use Vue3 if efficiency problems persist despite your best efforts at optimization.

Whether or not you want to migrate your application to Vue3 depends on its size and complexity. The majority of the syntax and techniques in Vue 2 are the same as in Vue3. However, if you want to use some of the changes mentioned above, then migrating would be a better idea.

Vue.js in AppMaster project

The AppMaster platform uses the VueJS framework, or rather the third version of the framework, to create a front-end application for our users. Vue 3 is used to create admin, panels, and client portals, and the whole interface of AppMaster studio is actually made using the VueJS framework too.

We use a special approach called micro-frontends or front-end microservices to be able to quickly and efficiently develop our product; for example, each data model editor and business process editor is a completely separate front-end application in our platform. This allows us to develop very quickly and independently from the point of view of the development team, which increases the overall speed of our product. All these advantages our customers can get using our applications.

In the future, in addition to the SPA single-page application mode, we will add the SSR (server-side rendering) mode, which will allow our customers to create not only admin panels and custom portals but also full-featured websites with very high SEO optimization.

no-code

About no-code

One of the key elements influencing the democratization of coding is the no-code development approach. Nowadays, a greater number of people can access programming in general with the absence of coding. It makes web design, mobile application development, and responsive web development simpler.

AppMaster is among the applications that can be used for automatically creating source code. You may view and inspect the code at any moment. With AppMaster, you have the option of customizing project information using computer language. We also let people export the code if they want to. This is a guarantee that you have complete control and ownership over the application you are working on with AppMaster.

Conclusions

If you want a more detailed explanation of how Vue3 is different from Vue 2, along with code snippets, you can go through the official Vue.js documentation. We have mentioned most of the major changes that you should be aware of. It is important that you stay aware of updates to Vue3 if you are interested in building applications with this framework.