How to Expertly Convert Your Svelte Application to Vue

Transitioning from Svelte to Vue: A Developer's Guide

In the ever-evolving landscape of web development, the choice of frameworks and libraries can significantly impact the efficiency, maintainability, and scalability of your projects. Svelte and Vue are two prominent players in this field, each with its unique approach to building reactive user interfaces. Developers may consider converting from Svelte to Vue for various reasons, such as Vue's larger ecosystem, more extensive community support, or the need to integrate with existing Vue projects. This article aims to guide you through the transition from Svelte to Vue, highlighting key differences and providing insights into how to adapt your coding practices to Vue's paradigms.

Understanding the Differences

Before diving into the conversion process, it's crucial to understand the fundamental differences between Svelte and Vue. Svelte is a compiler that generates efficient JavaScript code to update the DOM directly, whereas Vue is a progressive framework that uses a virtual DOM to apply changes reactively. This distinction affects how you structure your applications and manage state changes.

Svelte	Vue
Compiler-based	Runtime-based framework
Direct DOM updates	Virtual DOM
Reactive assignments	Reactive data properties
Stores for state management	Vuex for state management
Single-file components (optional)	Single-file components (standard)

Syntax Differences

When converting from Svelte to Vue, you'll encounter syntax differences that reflect the contrasting philosophies of the two frameworks. The following table provides a comparison of common syntax used in both Svelte and Vue.

Svelte Syntax	Vue Syntax
`<script>`	`<script>`
`{#if condition}...{/if}`	`v-if="condition"`
`{#each items as item}...{/each}`	`v-for="item in items"`
`bind:value`	`v-model`
`on:click`	`@click`

Converting Components

Components are the building blocks of both Svelte and Vue applications. However, the way you define, compose, and manage data within components differs between the two frameworks. Let's look at how a simple component conversion might look.

Svelte Component Example:


<script>
    let count = 0;
    function increment() {
        count++;
    }
</script>

<button on:click={increment}>
    Clicked {count} {count === 1 ? 'time' : 'times'}
</button>

Vue Component Equivalent:


<template>
    <button @click="increment">
        Clicked {{ count }} {{ count === 1 ? 'time' : 'times' }}
    </button>
</template>

<script>
export default {
    data() {
        return { count: 0 };
    },
    methods: {
        increment() {
            this.count++;
        }
    }
};
</script>

Handling State and Reactivity

State management and reactivity are core concepts in both Svelte and Vue. Svelte uses reactive assignments to automatically update the DOM when state changes, while Vue uses a reactive system based on data properties and a virtual DOM. Here's how you might convert a reactive state from Svelte to Vue.

Svelte Reactive Statement:


$: doubledCount = count * 2;

Vue Computed Property:


computed: {
    doubledCount() {
        return this.count * 2;
    }
}

Conclusion

Transitioning from Svelte to Vue requires an understanding of the conceptual and syntactical differences between the two frameworks. While Svelte offers a lean and compiler-centric approach, Vue provides a more feature-rich ecosystem with a virtual DOM and a comprehensive set of tools. By carefully mapping Svelte concepts to their Vue counterparts, you can effectively convert your applications and leverage Vue's powerful features to build scalable and maintainable web applications.

Converting from Svelte to Vue

Project Setup

Initialize a new Vue project using Vue CLI or Vite.
Install necessary Vue dependencies and plugins.
Configure your build tools (Webpack, Rollup, etc.) for Vue.
Set up a linter and formatter, such as ESLint and Prettier, for Vue syntax.

Component Conversion

Convert Svelte single-file components (.svelte) to Vue single-file components (.vue).
Update the template syntax from Svelte to Vue directives.
Refactor Svelte reactive statements to Vue's reactivity system (ref, reactive, computed).
Replace Svelte's event modifiers with Vue's event modifiers.
Adapt Svelte stores to Vue's state management, using Vuex or the Composition API.

Routing

Replace Svelte's routing solution with Vue Router.
Map existing routes and update the router configuration.
Update link navigation to use <router-link> instead of <a> tags.

State Management

Transition from Svelte's built-in state management to Vuex or Vue's Composition API.
Convert Svelte stores to Vuex stores or reactive objects.
Update any store subscriptions to use Vue's computed properties or watchers.

Styling

Adapt Svelte's scoped styles to Vue's scoped CSS.
Ensure that global styles are imported correctly in the Vue project.

Build and Deployment

Update build scripts to accommodate Vue's build process.
Ensure that Continuous Integration (CI) and Continuous Deployment (CD) pipelines are configured for Vue.
Test the production build and fix any deployment-related issues.

Testing

Update unit and integration tests to use Vue Test Utils.
Refactor any mock components or services to work with Vue.
Ensure end-to-end tests are compatible with the new Vue application.

Code Examples

Below are some code conversion examples from Svelte to Vue:

Reactive Variables:

<script>
  let count = 0;
  </script>
  <button on:click="{() => count += 1}">Increment</button>

<script>
  import { ref } from 'vue';
  const count = ref(0);
  </script>
  <button @click="count++">Increment</button>

Conditional Rendering:

<script>
  let user = { loggedIn: true };
  </script>
  <div>
    {#if user.loggedIn}
      <p>Welcome back!</p>
    {/if}
  </div>

<script>
  import { ref } from 'vue';
  const user = ref({ loggedIn: true });
  </script>
  <div>
    <p v-if="user.loggedIn">Welcome back!</p>
  </div>

Options

Toggles