The Rise of Svelte: Can It Surpass Vue in Popularity?
In the ever-evolving landscape of web development, new frameworks are constantly emerging to challenge the status quo. Svelte, a relatively new framework, is gaining popularity at an exponential rate, much like Vue did a few years ago. As we examine the syntactical differences between Svelte and Vue, it’s clear that Svelte has taken a page out of Vue’s playbook, implementing and improving on the features that made Vue so loved.
Understanding Vue
Vue is a progressive, open-source JavaScript framework for building user interfaces and single-page applications. It’s designed to be incrementally integrated, allowing developers to add Vue to any part of an existing frontend project without having to rebuild everything. Vue relies solely on JavaScript, unlike frameworks like Svelte, which uses a compiler. At its core, Vue utilizes concepts inherited from Angular and React, such as reactive, two-way data binding and Virtual DOM diffing.
Introducing Svelte
Svelte is an open-source, frontend framework for creating interactive UIs. Unlike Vue, Svelte is a compiler that converts declarative state-driven components into imperative JavaScript code that directly updates the DOM. By parsing and compiling its declarative code into JavaScript code during build time, Svelte avoids the performance overhead associated with Virtual DOM diffing, making it 2x faster than frameworks that use the Virtual DOM and are compiled at runtime.
A Tale of Two Frameworks
As we delve into the world of Svelte and Vue, it’s clear that both frameworks share many similarities. Both use single-file components, which encapsulate the template, logic, and styling of a component in a single file. However, Svelte doesn’t have a dedicated template tag for encapsulating the markup in a component like Vue’s <template>.
Declarative Rendering
One of the most noticeable differences between the two templates is the method of referencing declarative data properties to the template. Svelte uses single curly braces { }, while Vue uses double curly braces {{ }}, also known as the mustache syntax.
Data Binding
Both frameworks use special attributes called directives to bind data from the model to the template. Svelte and Vue use the bind directive, which accepts arguments denoted by a colon, as well as a data property or reactive variable that will be bound to the element it’s defined on.
Computed Properties
Svelte uses the dollar sign $ to define a computed value by prefixing it to a top-level assignment, or assignments that are not inside a code block or function. Vue, on the other hand, defines computed properties in the component object and assigns named functions that return a code expression based on the data model.
Events
Both frameworks handle events in a similar way using the on directive, which accepts an argument denoted by a colon. An event handler directive traditionally evokes a function that returns an expression when triggered.
Reactivity
Reactivity is a style of programming that allows us to declaratively adjust to change. Svelte and Vue handle reactivity differently. Svelte creates reactive variables by default via assignments, and every variable declared with the let keyword is automatically reactive. Vue, on the other hand, uses the data object in the option API and the ref() method in the Composition API to create reactive variables.
Build Time Reactivity
Svelte’s compiler operates at build time, parsing the HTML elements, logic blocks, and conditionals, and breaking down the parsed code into smaller pieces called tokens. The compiler then creates a tree-like structure from the list of tokens called an abstract syntax tree (AST). Based on the AST, the compiler generates a code output.
Vue Runtime Reactivity
Vue’s reactivity module allows us to create reactive JavaScript objects that we can watch for changes. The mount module compiles HTML templates into render functions, and the renderer module renders and updates the component onto a webpage.
The Verdict
While Svelte brings many perks to the table, its lack of flexibility and small community support may deter some developers from migrating to it. Vue, on the other hand, has had years to implement and improve on these aspects. As Svelte continues to evolve, it will be interesting to see how it compares to Vue in the long run.