How to add external JS scripts to VueJS Components?

A simple and effective way to solve this, it's by adding your external script into the vue mounted() of your component. I will illustrate you with the Google Recaptcha script:

<template>
   .... your HTML
</template>

<script>
  export default {
    data: () => ({
      ......data of your component
    }),
    mounted() {
      let recaptchaScript = document.createElement('script')
      recaptchaScript.setAttribute('src', 'https://www.google.com/recaptcha/api.js')
      document.head.appendChild(recaptchaScript)
    },
    methods: {
      ......methods of your component
    }
  }
</script>

Source: https://medium.com/@lassiuosukainen/how-to-include-a-script-tag-on-a-vue-component-fe10940af9e8

I have downloaded some HTML template that comes with custom js files and jquery. I had to attach those js to my app. and continue with Vue.

Found this plugin, it's a clean way to add external scripts both via CDN and from static files https://www.npmjs.com/package/vue-plugin-load-script

// local files
// you have to put your scripts into the public folder. 
// that way webpack simply copy these files as it is.
Vue.loadScript("/js/jquery-2.2.4.min.js")

// cdn
Vue.loadScript("https://maps.googleapis.com/maps/api/js")

UPDATE: This no longer works in Vue 3. You will receive this error:

VueCompilerError: Tags with side effect ( and ) are ignored in client component templates.

If you are trying to embed external js scripts to the vue.js component template, follow below:

I wanted to add a external JavaScript embed code to my component like this:

<template>
  <div>
    This is my component
    <script src="https://badge.dimensions.ai/badge.js"></script>
  </div>
<template>

And Vue showed me this error:

Templates should only be responsible for mapping the state to the UI. Avoid placing tags with side-effects in your templates, such as , as they will not be parsed.

The way I solved it was by adding type="application/javascript" (See this question to learn more about MIME type for js):

<script type="application/javascript" defer src="..."></script>

You may notice the defer attribute. If you want to learn more watch this video by Kyle

This can be simply done like this.

  created() {
    var scripts = [
      "https://cloudfront.net/js/jquery-3.4.1.min.js",
      "js/local.js"
    ];
    scripts.forEach(script => {
      let tag = document.createElement("script");
      tag.setAttribute("src", script);
      document.head.appendChild(tag);
    });
  }

You can use the vue-head package to add scripts, and other tags to the head of your vue component.

Its as simple as:

var myComponent = Vue.extend({
  data: function () {
    return {
      ...
    }
  },
  head: {
    title: {
      inner: 'It will be a pleasure'
    },
    // Meta tags
    meta: [
      { name: 'application-name', content: 'Name of my application' },
      { name: 'description', content: 'A description of the page', id: 'desc' }, // id to replace intead of create element
      // ...
      // Twitter
      { name: 'twitter:title', content: 'Content Title' },
      // with shorthand
      { n: 'twitter:description', c: 'Content description less than 200 characters'},
      // ...
      // Google+ / Schema.org
      { itemprop: 'name', content: 'Content Title' },
      { itemprop: 'description', content: 'Content Title' },
      // ...
      // Facebook / Open Graph
      { property: 'fb:app_id', content: '123456789' },
      { property: 'og:title', content: 'Content Title' },
      // with shorthand
      { p: 'og:image', c: 'https://example.com/image.jpg' },
      // ...
    ],
    // link tags
    link: [
      { rel: 'canonical', href: 'http://example.com/#!/contact/', id: 'canonical' },
      { rel: 'author', href: 'author', undo: false }, // undo property - not to remove the element
      { rel: 'icon', href: require('./path/to/icon-16.png'), sizes: '16x16', type: 'image/png' }, 
      // with shorthand
      { r: 'icon', h: 'path/to/icon-32.png', sz: '32x32', t: 'image/png' },
      // ...
    ],
    script: [
      { type: 'text/javascript', src: 'cdn/to/script.js', async: true, body: true}, // Insert in body
      // with shorthand
      { t: 'application/ld+json', i: '{ "@context": "http://schema.org" }' },
      // ...
    ],
    style: [
      { type: 'text/css', inner: 'body { background-color: #000; color: #fff}', undo: false },
      // ...
    ]
  }
})

Check out this link for more examples.

The top answer of create tag in mounted is good, but it has some problems: If you change your link multiple times, it will repeat create tag over and over.

So I created a script to resolve this, and you can delete the tag if you want.

It's very simple, but can save your time to create it by yourself.

// PROJECT/src/assets/external.js

function head_script(src) {
    if(document.querySelector("script[src='" + src + "']")){ return; }
    let script = document.createElement('script');
    script.setAttribute('src', src);
    script.setAttribute('type', 'text/javascript');
    document.head.appendChild(script)
}

function body_script(src) {
    if(document.querySelector("script[src='" + src + "']")){ return; }
    let script = document.createElement('script');
    script.setAttribute('src', src);
    script.setAttribute('type', 'text/javascript');
    document.body.appendChild(script)
}

function del_script(src) {
    let el = document.querySelector("script[src='" + src + "']");
    if(el){ el.remove(); }
}


function head_link(href) {
    if(document.querySelector("link[href='" + href + "']")){ return; }
    let link = document.createElement('link');
    link.setAttribute('href', href);
    link.setAttribute('rel', "stylesheet");
    link.setAttribute('type', "text/css");
    document.head.appendChild(link)
}

function body_link(href) {
    if(document.querySelector("link[href='" + href + "']")){ return; }
    let link = document.createElement('link');
    link.setAttribute('href', href);
    link.setAttribute('rel', "stylesheet");
    link.setAttribute('type', "text/css");
    document.body.appendChild(link)
}

function del_link(href) {
    let el = document.querySelector("link[href='" + href + "']");
    if(el){ el.remove(); }
}

export {
    head_script,
    body_script,
    del_script,
    head_link,
    body_link,
    del_link,
}

And you can use it like this:

// PROJECT/src/views/xxxxxxxxx.vue

......

<script>
    import * as external from '@/assets/external.js'
    export default {
        name: "xxxxxxxxx",
        mounted(){
            external.head_script('/assets/script1.js');
            external.body_script('/assets/script2.js');
            external.head_link('/assets/style1.css');
            external.body_link('/assets/style2.css');
        },
        destroyed(){
            external.del_script('/assets/script1.js');
            external.del_script('/assets/script2.js');
            external.del_link('/assets/style1.css');
            external.del_link('/assets/style2.css');
        },
    }
</script>

......

With Vue 3, I use mejiamanuel57 answer with an additional check to ensure the script tag hasn't been loaded already.

    mounted() {
        const scripts = [
            "js/script1.js",
            "js/script2.js"
        ];
        scripts.forEach(script => {
            let tag = document.head.querySelector(`[src="${ script }"`);
            if (!tag) {
                tag = document.createElement("script");
                tag.setAttribute("src", script);
                tag.setAttribute("type", 'text/javascript');
                document.head.appendChild(tag); 
            }
        });
    // ...

The answer from mejiamanuel57 is great, but I want to add a couple of tips that work in my case (I spent some hours on them). First, I needed to use the "window" scope. Also, if you need to access any Vue element inside the "onload" function, you need a new variable for the "this" instance.

<script>
import { mapActions } from "vuex";
export default {
  name: "Payment",
  methods: {
    ...mapActions(["aVueAction"])
  },
  created() {
    let paywayScript = document.createElement("script");
    let self = this;
    paywayScript.onload = () => {
      // call to Vuex action.
      self.aVueAction();
      // call to script function
      window.payway.aScriptFunction();
    };
    // paywayScript.async = true;
    paywayScript.setAttribute(
      "src",
      "https://api.payway.com.au/rest/v1/payway.js"
    );
    document.body.appendChild(paywayScript);
  }
};
</script>

I worked with this on Vue 2.6. Here there is an explanation about how the trick "let self = this;" works in Javascript:

What does 'var that = this;' mean in JavaScript?

Simplest solution is to add the script in the index.html file of your vue-project

index.html:

<!DOCTYPE html>
<html lang="en">
   <head>
      <meta charset="utf-8">
      <title>vue-webpack</title>
   </head>
   <body>
      <div id="app"></div>
      <!-- start Mixpanel --><script type="text/javascript">(function(c,a){if(!a.__SV){var b=window;try{var d,m,j,k=b.location,f=k.hash;d=function(a,b){return(m=a.match(RegExp(b+"=([^&]*)")))?m[1]:null};f&&d(f,"state")&&(j=JSON.parse(decodeURIComponent(d(f,"state"))),"mpeditor"===j.action&&(b.sessionStorage.setItem("_mpcehash",f),history.replaceState(j.desiredHash||"",c.title,k.pathname+k.search)))}catch(n){}var l,h;window.mixpanel=a;a._i=[];a.init=function(b,d,g){function c(b,i){var a=i.split(".");2==a.length&&(b=b[a[0]],i=a[1]);b[i]=function(){b.push([i].concat(Array.prototype.slice.call(arguments,
         0)))}}var e=a;"undefined"!==typeof g?e=a[g]=[]:g="mixpanel";e.people=e.people||[];e.toString=function(b){var a="mixpanel";"mixpanel"!==g&&(a+="."+g);b||(a+=" (stub)");return a};e.people.toString=function(){return e.toString(1)+".people (stub)"};l="disable time_event track track_pageview track_links track_forms track_with_groups add_group set_group remove_group register register_once alias unregister identify name_tag set_config reset opt_in_tracking opt_out_tracking has_opted_in_tracking has_opted_out_tracking clear_opt_in_out_tracking people.set people.set_once people.unset people.increment people.append people.union people.track_charge people.clear_charges people.delete_user people.remove".split(" ");
         for(h=0;h<l.length;h++)c(e,l[h]);var f="set set_once union unset remove delete".split(" ");e.get_group=function(){function a(c){b[c]=function(){call2_args=arguments;call2=[c].concat(Array.prototype.slice.call(call2_args,0));e.push([d,call2])}}for(var b={},d=["get_group"].concat(Array.prototype.slice.call(arguments,0)),c=0;c<f.length;c++)a(f[c]);return b};a._i.push([b,d,g])};a.__SV=1.2;b=c.createElement("script");b.type="text/javascript";b.async=!0;b.src="undefined"!==typeof MIXPANEL_CUSTOM_LIB_URL?
         MIXPANEL_CUSTOM_LIB_URL:"file:"===c.location.protocol&&"//cdn.mxpnl.com/libs/mixpanel-2-latest.min.js".match(/^\/\//)?"https://cdn.mxpnl.com/libs/mixpanel-2-latest.min.js":"//cdn.mxpnl.com/libs/mixpanel-2-latest.min.js";d=c.getElementsByTagName("script")[0];d.parentNode.insertBefore(b,d)}})(document,window.mixpanel||[]);
         mixpanel.init("xyz");
      </script><!-- end Mixpanel -->
      <script src="/dist/build.js"></script>
   </body>
</html>

mounted() {
    if (document.getElementById('myScript')) { return }
    let src = 'your script source'
    let script = document.createElement('script')
    script.setAttribute('src', src)
    script.setAttribute('type', 'text/javascript')
    script.setAttribute('id', 'myScript')
    document.head.appendChild(script)
}


beforeDestroy() {
    let el = document.getElementById('myScript')
    if (el) { el.remove() }
}

To keep clean components you can use mixins.

On your component import external mixin file.

Profile.vue

import externalJs from '@client/mixins/externalJs';

export default{
  mounted(){
    this.externalJsFiles();
  }
}

externalJs.js

import('@JSassets/js/file-upload.js').then(mod => {
  // your JS elements 
})

babelrc (I include this, if any get stuck on import)

{
  "presets":["@babel/preset-env"],
  "plugins":[
    [
     "module-resolver", {
       "root": ["./"],
       alias : {
         "@client": "./client",
         "@JSassets": "./server/public",
       }
     }
    ]
}

well, this is my practice in qiokian (a live2d anime figure vuejs component):

(below is from the file src/qiokian.vue)

<script>
export default {
    data() {
        return {
            live2d_path:
                'https://cdn.jsdelivr.net/gh/knowscount/live2d-widget@latest/',
            cdnPath: 'https://cdn.jsdelivr.net/gh/fghrsh/live2d_api/',
        }
    },
<!-- ... -->
        loadAssets() {
            // load waifu.css live2d.min.js waifu-tips.js
            if (screen.width >= 768) {
                Promise.all([
                    this.loadExternalResource(
                        this.live2d_path + 'waifu.css',
                        'css'
                    ),
<!-- ... -->
        loadExternalResource(url, type) {
            // note: live2d_path parameter should be an absolute path
            // const live2d_path =
            //   "https://cdn.jsdelivr.net/gh/knowscount/live2d-widget@latest/";
            //const live2d_path = "/live2d-widget/";
            return new Promise((resolve, reject) => {
                let tag

                if (type === 'css') {
                    tag = document.createElement('link')
                    tag.rel = 'stylesheet'
                    tag.href = url
                } else if (type === 'js') {
                    tag = document.createElement('script')
                    tag.src = url
                }
                if (tag) {
                    tag.onload = () => resolve(url)
                    tag.onerror = () => reject(url)
                    document.head.appendChild(tag)
                }
            })
        },
    },
}

If you're using Vue 3 and the Composition API (I highly recommend), and you're using <script> tags a lot, you can write a "composable" function for this:

import { onMounted } from "vue";

export const useScript = (src, async = false, defer = false) => {
  onMounted(() => {
    // check if script already exists
    if (document.querySelector(`head script[src="${src}"`)) return;

    // add tag to head
    const tag = document.createElement("script");
    tag.setAttribute("src", src);
    if (async) tag.setAttribute("async", "");
    if (defer) tag.setAttribute("defer", "");
    tag.setAttribute("type", "text/javascript");
    document.head.append(tag);
  });
};

OR, if you are using VueUse (I also highly recommend), you can use their existing useScriptTag function.

There is a vue component for this usecase

https://github.com/TheDynomike/vue-script-component#usage

<template>
    <div>
        <VueScriptComponent script='<script type="text/javascript"> alert("Peekaboo!"); </script>'/>
    <div>
</template>

<script>
import VueScriptComponent from 'vue-script-component'

export default {
  ...
  components: {
    ...
    VueScriptComponent
  }
  ...
}
</script>