evgarik / vue3-runtime-template

Vue component for compiling templates on the fly using a v-html like API

vue3-runtime-template

A Vue.js components that makes easy compiling and interpreting a Vue.js template at runtime by using a v-html like API.

vue3-runtime-template is based off v-runtime-template but tweaked to work with Vue 3.

Motivation

This library solves the case where you get a vue-syntax template string on runtime, usually from a server. Think of a feature where you allow the user to create their own interfaces and structures. You save that as a vue template in your database, which your UI will request later. While components are pre-compiled at build time, this case isn't (since the template is received at runtime) and needs to be compiled at runtime.

vue3-runtime-template compiles that template and attaches it to the scope of the component that uses it, so it has access to its data, props, methods and computed properties.

Think of it as the v-html equivalent that also understands vue template syntax (while v-html is just for plain HTML).

Getting Started

Install it:

npm install vue3-runtime-template

You must use the with-compiler Vue.js version. This is needed in order to compile on-the-fly Vue.js templates. For that, you can set a webpack alias for vue to the correct file.

For example, if you use the Vue CLI, create or modify the vue.config.js file adding the following alias:

// vue.config.js
module.exports = {
    configureWebpack: {
      resolve: {
        alias: {
          vue$: 'vue/dist/vue.esm-bundler.js',
      // ...

In Nuxt v2, open the nuxt.config.js file and extend the webpack config by adding the following line to the extend key:

// nuxt.config.js
{
  build: {
    extend(config, { isDev, isClient }) {
      config.resolve.alias["vue"] = "vue.esm-bundler.js";
      // ...

In Nuxt v3, open the nuxt.config.js file and extend the vite config by adding the following hook, just on client:

// nuxt.config.js
{
 (...)

 hooks: {
      'vite:extendConfig': (config, { isClient, isServer }) => {
        if (isClient) {
          config.resolve.alias.vue = 'vue/dist/vue.esm-bundler'
        }
      },
    },

  (...)

You can read about different bundles of Vue in the official help guides.

Usage

You just need to import the vue3-runtime-template component, and pass the template you want:

<template>
	<div>
		<v-runtime-template :template="template"></v-runtime-template>
	</div>
</template>

<script>
import VRuntimeTemplate from "vue3-runtime-template";
import AppMessage from "./AppMessage";

export default {
  data: () => ({
    name: "Mellow",
    template: `
      <app-message>Hello {{ name }}!</app-message>
    `
  }),
  components: {
    AppMessage,
    VRuntimeTemplate
  }
};
</script>

The template you pass have access to the parent component instance. For example, in the last example we're using the AppMessage component and accessing the {{ name }} state variable.

But you can access computed properties and methods as well from the template:

export default {
  data: () => ({
    name: "Mellow",
    template: `
      <div>
        <app-message>Hello {{ name }}!</app-message>
        <button @click="sayHi">Say Hi!</button>
        <p>{{ someComputed }}</p>
      </div>
		`,
  }),
  computed: {
    someComputed() {
      return "Wow, I'm computed";
    },
  },
  methods: {
    sayHi() {
      console.log("Hi");
    },
  },
};

Limitations

Keep in mind that the template can only access the instance properties of the component who is using it.

Comparison

vue3-runtime-template VS v-html

TL;DR: If you need to interpret only HTML, use v-html. Use this library otherwise.

They both have the same goal: to interpret and attach a piece of structure to a scope at runtime. The difference is, [v-html](https://vuejs.org/v2/api/#v-html) doesn't understand vue template syntax, but only HTML. So, while this code works:

<template>
	<div v-html="template"></div>
</template>

<script>
export default {
  data: () => ({
    template: `
      <a href="/mike-page">Go to Mike page</a>
    `

the following wouldn't since it uses the custom router-link component:

<router-link to="mike-page">Go to Mike page</router-link>

But you can use vue3-runtime-template, which uses basically the same API than v-html:

<template>
	<vue3-runtime-template :template="template"></vue3-runtime-template>
</template>

<script>
export default {
  data: () => ({
    template: `
      <router-link to="mike-page">Go to Mike page</router-link>
    `

vue3-runtime-template VS dynamic components (<component>)

Dynamic components have somewhat different goal: to render a component dynamically by binding it to the is prop. Although, these components are usually pre-compiled. However, the goal of vue3-runtime-template can be achieved just by using the component options object form of dynamic components.

In fact, vue3-runtime-template uses that under the hood (in the render function form) along with other common tasks to achieve its goal.