Importing javascript file for use within vue component - javascript

I am working on a project that requires using a js plugin. Now that we're using vue and we have a component to handle the plugin based logic, I need to import the js plugin file within the vue component in order to initialize the plugin.
Previously, this was handled within the markup as follows:
<script src="//api.myplugincom/widget/mykey.js
"></script>
This is what I tried, but I am getting a compile time error:
MyComponent.vue
import Vue from 'vue';
import * from '//api.myplugincom/widget/mykey.js';
export default {
data: {
My question is, what is the proper way to import this javascript file so I can use it within my vue component?
...

Include an external JavaScript file
Try including your (external) JavaScript into the mounted hook of your Vue component.
<script>
export default {
mounted() {
const plugin = document.createElement("script");
plugin.setAttribute(
"src",
"//api.myplugincom/widget/mykey.js"
);
plugin.async = true;
document.head.appendChild(plugin);
}
};
</script>
Reference: How to include a tag on a Vue component
Import a local JavaScript file
In the case that you would like to import a local JavaScript in your Vue component, you can import it this way:
MyComponent.vue
<script>
import * as mykey from '../assets/js/mykey.js'
export default {
data() {
return {
message: `Hello ${mykey.MY_CONST}!` // Hello Vue.js!
}
}
}
</script>
Suppose your project structure looks like:
src
- assets
- js
- mykey.js
- components
MyComponent.vue
And you can export variables or functions in mykey.js:
export let myVariable = {};
export const MY_CONST = 'Vue.js';
export function myFoo(a, b) {
return a + b;
}
Note: checked with Vue.js version 2.6.10

try to download this script
import * from '{path}/mykey.js'.
or import script
<script src="//api.myplugincom/widget/mykey.js"></script>
in <head>, use global variable in your component.

For scripts you bring in the browser way (i.e., with tags), they generally make some variable available globally.
For these, you don't have to import anything. They'll just be available.
If you are using something like Webstorm (or any of the related JetBrains IDEs), you can add /* global globalValueHere */ to let it know that "hey, this isn't defined in my file, but it exists." It isn't required, but it'll make the "undefined" squiggly lines go away.
For example:
/* global Vue */
is what I use when I am pulling Vue down from a CDN (instead of using it directly).
Beyond that, you just use it as you normally would.

I wanted to embed a script on my component and tried everything mentioned above, but the script contains document.write. Then I found a short article on Medium about using postscribe which was an easy fix and resolved the matter.
npm i postscribe --save
Then I was able to go from there. I disabled the useless escape from eslint and used #gist as the template's single root element id:
import postscribe from 'postscribe';
export default {
name: "MyTemplate",
mounted: function() {
postscribe(
"#gist",
/* eslint-disable-next-line */
`<script src='...'><\/script>`
);
},
The article is here for reference:
https://medium.com/#gaute.meek/how-to-add-a-script-tag-in-a-vue-component-34f57b2fe9bd

For anyone including an external JS file and having trouble accessing the jQuery prototype method(s) inside of the loaded script.
Sample projects I saw in vanilla JS, React and Angular were simply using:
$("#someId").somePlugin(options)
or
window.$("#someId").somePlugin(options)
But when I try either of those in my VueJS component I receive:
Error: _webpack_provided_window_dot$(...).somePluginis not a function
I examined the window object after the resources had loaded I was able to find the jQuery prototype method in the window.self read-only property that returns the window itself:
window.self.$("#someId").somePlugin(options)
Many examples show how to load the external JS file in VueJS but not actually using the jQuery prototype methods within the component.

Related

Why components defined by "customElements.define()" are not globally usable?

I am working on a Svelte project, but it contains some web components.
The issue I am facing is that some web components defined by the customElements.define() Typescript function are not usable unless I import them specifically in the user component.
For example, a web component is defined in the following way:
// File name is oneWebComponent.js
export class OneWebComponent extends HTMLElement {
...
customElements.define('one-web-component', OneWebComponent);
}
Then, there is another JS file, which contains a "factory" function that creates different types of Web Components:
export const createElement = (tagName) => {
return document.createElement(tagName);
}
If I call it like createElement('one-web-component'), the resulting component is not really the one defined in OneWebComponent. I know that because the functions defined there are not callable (error: XXX is not a function).
But if I import oneWebComponent.js in the factory file like below, it works correctly:
// This line is newly added:
import './oneWebComponent.js';
export const createElement = (tagName) => {
return document.createElement(tagName);
}
That means, if I have multiple types of web components, and the factory function is called in multiple places, I will have to import each type of web component in each place, which is tedious.
I wonder if there is a way to just make the components defined by customElements.define() globally usable?
That means, no imports needed, just passing the tag name into document.createElement() and it will create the web component correctly.
Am I missing any configs?
Thanks in advance!
As #Bergi pointed out, the customElements.define() function is not executed if the file is not imported anywhere.
So I only needed to import all of the web components in the top level of the app, a file like app.svelte or main.js for example, then the function will run, and the tags are defined and usable across the app.

Importing / exporting Javascript Object Properties

I support a relatively complex legacy codebase, but am looking to modernise it a little by bringing in Webpack so that we'd have import & export capabilities in JS.
The problem I'm having is that we use a global object called App where we define and add different properties depending on the page. So for example we have the following file where we instantiate App (loaded on all pages):
app.js
const App = (() => {
const obj = {
Lib: {},
Util: {},
// etc
}
return obj;
})();
Then in another file we add to App.Lib just for the specific page that needs it:
lazyload.js
App.Lib.Lazyload = (() => {
// lazyload logic
})();
We simply concatenate the files during the bundling process, but obviously this is not ideal as none of the files have no knowledge of what goes on outside of it.
Exporting only seems to work for the top level object (where the object is defined), so anything I add to it elsewhere cannot be exported again. For example if I add export default App.Lib.Lazyload; at the end of lazyload.js and then try to import it elsewhere it will not import the Lazyload property.
Is there any way to get this to work without major refactor? If not, would you have any suggestions about the best way to handle it?
I don't think you can import Object.properties in JS. If you want to bundle specific packages (say Lazyload) for packages that need them, you might try:
//lazyload.js
export const LazyLoad = {
//lazyload logic
}
then somewhere else...
import {LazyLoad} from 'path/to/lazyload.js';
// assuming App has already been created/instantiated
App.Lib.Lazyload = LazyLoad;
Using Export Default...
//lazyload.js
const LazyLoad = {};
export default LazyLoad;
then...
import LazyLoad from 'path/to/lazyload.js';
App.Lib.LazyLoad = LazyLoad;
You can find help with Imports and Exports at MDN.

How to use external JavaScript objects in Vue.js methods

I'm trying to get Stripe working with my Vue.js 2 application. For PCI-DSS reasons, Stripe requires that their Javascript is always loaded from js.stripe.com. I've followed the instructions in:
How to add external JS scripts to VueJS Components
How to include a CDN to VueJS CLI without NPM or Webpack?
but I get a 'Stripe' is not defined error when I try to use the library. These solutions seemed to be aimed at merely getting a <script> tag into the output HTML (e.g. for analytics), not actually consuming the functions and objects in that script.
Here's what my component Javascript looks like:
<script>
export default {
name: "PaymentPage",
mounted() {
let stripeScript = document.createElement('script');
stripeScript.setAttribute('src', 'https://js.stripe.com/v3/');
document.head.appendChild(stripeScript);
let s = Stripe('pk_test_Fooo');
console.log(s);
}
}
</script>
I also tried adding the script tag to my public/index.html file instead, but I get the same outcome. This would probably be my preferred route, since Stripe encourages developers to import their script on all pages on the site.
<!DOCTYPE html>
<html lang="en">
<head>
// ...
<script src="https://js.stripe.com/v3/"></script>
</head>
How can I pull a script from an external CDN and use it within my component's Javascript?
I'm aware of some libraries to integrate Vue.js with Stripe (e.g. matfish2/vue-stripe and jofftiquez/vue-stripe-checkout), but the former doesn't import properly for me (I'm hitting issue #24) and the latter is built against the older Stripe API and the new version is still in beta.
You aren't giving the script time to load before checking if Stripe is there. What you need is something like this:
<script>
export default {
name: "PaymentPage",
mounted() {
let stripeScript = document.createElement('script');
stripeScript.setAttribute('src', 'https://js.stripe.com/v3/');
stripeScript.onload = () => {
let s = Stripe('pk_test_Fooo');
console.log(s);
};
document.head.appendChild(stripeScript);
}
}
</script>
Thanks to yuriy636's comment, I realised that errors were only from the linter, which presumably can't statically figure out what I'm up to.
I opted to put the script into index.html, then ensured I squashed linter errors with:
// eslint-disable-next-line no-undef
let s = Stripe('pk_test_Fooo');
In my case, I still had errors calling functions of the specific script. So it was required to specify 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>
export default {
name: "PaymentPage",
mounted() {
let stripeScript = document.createElement('script');
// new variable for Vue elements.
let self = this;
stripeScript.onload = () => {
// call a script function using 'window' scope.
window.Stripe('pk_test_Fooo');
// call other Vue elements
self.otherVueMethod();
};
stripeScript.setAttribute('src', 'https://js.stripe.com/v3/');
document.head.appendChild(stripeScript);
}
}
I worked with this on Vue 2.6.
Just install the npm package npm install #stripe/stripe-js and use it like a regular import
import { loadStripe } from "#stripe/stripe-js";
export default {
async mounted() {
// init stripe
const stripe = await loadStripe('your_stripe_key_here');
this.stripe = stripe; // store the stripe instance
// access the stripe instance in your methods or where you want to use them
},
}
It's working as of 6th Jan 2022.

How to use an external non vue script in vue

I try to use an external script (https://libs.crefopay.de/3.0/secure-fields.js) which is not vue based
I added the script via -tags into index.html
But when I try to intsanciate an object, like in the excample of the script publisher.
let secureFieldsClientInstance =
new SecureFieldsClient('xxxxx',
this.custNo,
this.paymentRegisteredCallback,
this.initializationCompleteCallback,
configuration)
Vue says "'SecureFieldsClient' is not defined"
If I use this.
let secureFieldsClientInstance =
new this.SecureFieldsClient('xxxxx',
this.custNo,
this.paymentRegisteredCallback,
this.initializationCompleteCallback,
configuration)
secureFieldsClientInstance.registerPayment()
Vue says: Error in v-on handler: "TypeError: this.SecureFieldsClient is not a constructor"
My Code:
methods: {
startPayment () {
this.state = null
if (!this.selected) {
this.state = false
this.msg = 'Bitte Zahlungsweise auswählen.'
} else {
localStorage.payment = this.selected
let configuration = {
url: 'https://sandbox.crefopay.de/secureFields/',
placeholders: {
}
}
let secureFieldsClientInstance =
new SecureFieldsClient('xxxxx',
this.custNo,
this.paymentRegisteredCallback,
this.initializationCompleteCallback,
configuration)
secureFieldsClientInstance.registerPayment()
// this.$router.replace({ name: 'payment' })
}
}
}
Where is my mistake?
EDIT:
Updated the hole question
Here is a minimal Vue app for the context your provided, which works:
https://codepen.io/krukid/pen/voxqPj
Without additional details it's hard to say what your specific problem is, but most probably the library gets loaded after your method executes, so window.SecureFieldsClient is expectedly not yet defined. Or, there is some runtime error that crashes your script and prevents your method from executing. There could be some other more exotic issues, but lacking a broader context I can only speculate.
To ensure your library loads before running any code from it, you should attach an onload listener to your external script:
mounted () {
let crefPayApi = document.createElement('script')
crefPayApi.onload = () => this.startPayment()
crefPayApi.setAttribute('src', 'https://libs.crefopay.de/3.0/secure-fields.js')
document.head.appendChild(crefPayApi)
},
I found the solution.
the import was never the problem.
I had just to ignore VUEs/eslints complaining about the missing "this" via // eslint-disable-next-line and it works.
So external fuctions/opbjects should be called without "this" it seems.
let secureFieldsClientInstance =
new SecureFieldsClient('xxxxx',
this.custNo,
this.paymentRegisteredCallback,
this.initializationCompleteCallback,
configuration)
You could download the script and then use the import directive to load the script via webpack. You probably have something like import Vue from 'vue'; in your project. This just imports vue from your node modules.
It's the exact same thing for other external scripts, just use a relative path. When using Vue-CLI, you can do import i18n from './i18n';, where the src folder would contain a i18n.js
If you really want to use a CDN, you can add it like you normally would and then add it to the externals: https://webpack.js.org/configuration/externals/#externals to make it accessible from within webpack

Javascript JSX, illegal import declaration

I have a jsx file using React components with Reflux. There is only one tiny action:
var ClickedAction = Reflux.createActions([
'clicked'
]);
How can I move this action to another file? According to the JSX documentation, it should be easy to include other files:
// import all classes that do not start with "_" from "a.jsx"
import "a.jsx";
I tried to move it in actions/clickedAction.jsx (or .js) and import it using import "actions/clickedActions.jsx" but I keep getting Illegal import declaration. How can I achieve this?
I am not using RequireJS and would like to avoid it if possible. One alternative solution I have found is to include this in the HTML file,
<script type='text/javascript' src='xxxxx/actions/clickedAction.js")'></script>
, but this is not ideal and would like to find another way. Thanks for your attention and help.
If you use Babel:
export default ClickedAction; // in action file
Otherwise, use old modules:
module.exports = ClickedAction; // in action file
require('actions/clickedActions.jsx'); // in another file

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