Accessing Vue.js properties globally with globalProperties - LogRocket blog (2023)

Editor's Note: This guide to globally accessing properties in Vue.js with global properties was last updated on April 26, 2023 to reflect new changes in Vue 3 and add sections exploring further prototypes in Vue.

Vue.js is a widely used JavaScript framework that allows developers to createone page appsEUbuild user interfaces. Its flexibility is a notable advantage, allowing developers to customize the framework with additional features. As part of this flexibility, it provides easy access to properties and methods globally across the entire application.prototypesthat becameapp.config.globalPropertiesver 3.

This article will introduce you to using it.app.config.globalPropertiesCVue.jsfor adding custom properties and methods to your Vue instance, and how you can access them from any component in your application, instead of using multiple imports in your workflow.

jump forward

  • Introduction to Vue.js
  • What are prototypes?
    • Why use prototypes?
  • How to use prototypes in Vue.js
    • We create our demo
  • Discovering Use Cases for Vue.js Global Properties
    • Functions as global properties
    • Import global properties

Introduction to Vue.js

This post is suitable for developers of all skill levels, including beginners. However, there are a few things you should already have before going through this tutorial. Make sure you have the current versionNode.jsinstalled. You can verify that this is the case by running the command below in a terminal/command prompt:

node -vv18.16.0 # current LTS at write time

You will need a code editor - highly recommendedVS code. You will also need Vue installed on your computer. To install Vue, run the following command:

npm init[email protected]

This command will install and runcreate-vue, the official scaffolding tool for the Vue project. You will be asked to provide several optional features:

✔ Project name: …✔ Add TypeScript? … No / Yes✔ Add JSX support? … No / Yes✔ Add Vue router for single page development? … No / Yes✔ Add Pinia to state management? … No / Yes✔ Add Vitest to Unit Tests? … No / Yes✔ Add Cypress to unit and end-to-end tests? … No / Yes✔ Add ESLint for code quality? … No / Yes✔ Add Prettier to code formatting? … No / Yes Scaffolding project in ./...Prepare.

If you are not sure of an option, just chooseNOhittingTo typeFor now. Once the project is created, follow the instructions to install the dependencies and start the development server:

cdnpm installnpm run dev

You should now have your first Vue project running.

What are prototypes?

In Vue, a prototype is an object that contains properties and methods that can be added to a Vue instance or component, making them accessible throughout the application. Prototypes are added to Vue builder functions and can be accessed usingVue.prototypeobject. When a new Vue instance is created, it inherits all properties and methods defined in the prototype object. However, in newer Vue 3 apps,Vue.prototypethe property has been replacedapp.config.globalProperties.

Why use prototypes?

When working on a Vue project, the fastest way to access a new component in another or anothernestedone is to import the component or feature you need. However, this can quickly become inefficient as you will have to iterate through the import statements and even register components for each import (if they are components). Fortunately, Vue provides a more efficient way to handle this in cases where you've globally defined a data object or an incoming HTTP request. Thatapp.config.globalPropertiesz Vue 3app APIs, replacing Vue 2Vue.prototype.

To create a global property in a Vue application and access it using a property declaration instead of an import declaration, Vue provides an application API -app.config.globalProperties. In this way, you define a global property or data object, tell Vue to remember it as one, and then access it from any instance of the component in your Vue application.

How to use prototypes in Vue.js

As this is a global property, it is recommended that you use this object as little as possible in your projects. However, if a global property is defined that conflicts with the component's own property, the propertycomponent propertywill have higher priority. Defining a global property in your Vue application will look like this:

app.config.globalProperties.blogName = „LogRocket”

Here,blogNameis the name of the property or data, aLogRocketthe string is the value. With this setting, Vue.js gets this property (calledblogName, in our case) available to all instances of Vue throughout the project, even before instantiation.

We create our demo

To get through this section, you need to read this post from the beginning and install the Vue 3 project. To illustrate the syntax example in the section above, open your file./src/main.jsfile and add apropriedade globalso the whole file looks like this:

import { createApp } from "vue";import App from "./App.vue";import "./assets/main.css";const app = createApp(App);// define propriedades globaisapp.config.globalProperties.blogName = "Logrocket";app.mount("#aplicativo");

Now that you've defined the property, open it up./src/App.vueand copy the code block below:

Here you can see thatbefore creating lifecycle hookThe method was used to validate instance declarations for global properties. If you run the app on your development server withnpm run dev, you will see the saved name"LogRocket"displayed in the browser console and rendered in the model. Here's what it looks like:

Accessing Vue.js properties globally with globalProperties - LogRocket blog (1)

Discovering Use Cases for Vue.js Global Properties

Many data values, properties and tools such as HTTP resources can be assigned to global properties using Vueapp.config.globalProperties. In this section, I will introduce some of them.

Functions as global properties

Vue.js lets you add methods as global properties. This ensures that any instance where the global property is used has access to the logic defined in the property's definition. This includes access to useDezdata access,calculated propertiesand even other methods within any instance of Vue in the project. A quick example is using a stringreversalfunction. In your./src/main.jsfile, add a new global property under the old one:

// ./src/main.js// ...app.config.globalProperties.reverseString = função (valor) { this[value] = this[value].split("").reverse().join(" ");};//...

Then copy the code block below to your./src/App.vuefile:

HereCreatedlifecycle hook was used to loginreverse the ropefunction and if you run your application on development server you will see this"LogRocket"is printed in reverse order:

Accessing Vue.js properties globally with globalProperties - LogRocket blog (2)

Import global properties

If your app communicates with a third-party API, you'll typically need to importActionson each component you want to maketo takerequest of. In the terminal, stop the server and install Axios with the filenpm install axlesCommand. now go to yourapplication. to seethe file where you want to create the fileto takeask and copy this block of code inside:

This gives us something like this:

Accessing Vue.js properties globally with globalProperties - LogRocket blog (3)

You'll notice that for every component you want to make ato takerequest, you will have to repeat itmatterdeclaration. To solve this problem, Vue allows you to useglobal propertiessingle import function on any instance of Vue in the project. Now open yourmain.jsfile and copy the following block of code into it:

// ./src/main.jsimport { createApp } from "vue"; import application from "./App.vue"; import "./assets/main.css"; import axios from "axios"; const app = createApp(Application);// define global propertiesapp.config.globalProperties.blogName = "Logrocket";app.config.globalProperties.reverseString = function (value) { this[value] = this[value].split(" ").reverse ().join("");};app.config.globalProperties.axios = axios;app.mount("#application");

In yourapplication. to seefile, delete filematterdeclaration and use$ sharesalias that you have already created, for example:

And it still works:

Accessing Vue.js properties globally with globalProperties - LogRocket blog (4)

The complete code for this tutorial can be found hereGitHub.

Application

You were introduced to the concept of usingapp.config.globalPropertiesApplication API in Vue to make properties available globally to all Vue instances in your project. Also shown are the benefits of usingglobal properties, including a more efficient workflow. Happy hacking!

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FAQs

How do I access the DOM element in Vue? ›

If we want to reference a DOM element, we can use the ref attribute in Vue. Vue can store references to DOM elements in a property called $ref . The first thing we have to do, is add a ref attribute to the element we want to reference in our Javascript.

How do I access my Vue application in another system? ›

By default, Vue. js application can only be accessed by local IP. So as you see from the picture above, your project is running and can be accessed by the provided IP addresses – by visiting localhost:8080. or 127.0. 0.1:8080 in your browser.

How do I access refs in Vue? ›

Accessing the Refs ​
  1. To obtain the reference with Composition API, we need to declare a ref with the same name: ...
  2. The resulting ref is exposed on this.$refs : ...
  3. When ref is used inside v-for , the corresponding ref should contain an Array value, which will be populated with the elements after mount:

How do I see all DOM elements? ›

# Open the Properties pane
  1. Open DevTools. By default, the Elements panel opens.
  2. In the DOM tree, select a node.
  3. Open the Properties tab. If you can't see the tab, click More. , then select it from the drop-down menu.
May 5, 2022

How do you find all DOM elements? ›

The following HTML objects (and object collections) are also accessible:
  1. document.anchors.
  2. document.body.
  3. document.documentElement.
  4. document.embeds.
  5. document.forms.
  6. document.head.
  7. document.images.
  8. document.links.

How do I watch data property in Vue? ›

The Vue. js Watcher or watch property allows the developers to listen to the component data and run whenever they change a particular property. The watcher or watch property is a unique Vue. js feature that lets you keep an eye on one property of the component state and run a function when that property value changes.

How do I pass data from one component to another in Vue? ›

There are five ways to send the data from one component to another:
  1. Using Props (Parent to Child Communication)
  2. Using Events (Child to Parent Communication)
  3. Using Event Bus (Communication between any components)
  4. Using provide/inject (Parent to Child Communication)
  5. Using this.$refs (Parent to Child Communication)

How do I add Vue to my system path? ›

To use vue as command in cmd. Open the cmd as admin and run the the following command. setx /M path "%path%;%appdata%\npm" Now restart the cmd and run the vue again. It should work just fine.

How to access JSON data in Vue js? ›

Accessing JSON objects Vue.js
  1. import json from './json/data.json' Assign the import to a data property.
  2. <script> import json from './json/data.json' export default{ ...
  3. <template> <div> <div v-for="data in myJson">{{data}}</div> ...
  4. <script> import MY_JSON from './json/data.json' export default{ ...
  5. <template> <div>
Jul 18, 2019

How to fetch data from JSON file in Vue? ›

To get data from a local JSON file, we need to import the file into the component where we want to process the data. We do the import just like we would with a component, except the component name is replaced with whatever we want to call the data set.

How do I call an API in Vue? ›

How To Use an API with Vue. js
  1. Create the Basic Skeleton Of a Web Application.
  2. Create the Basic Vue.js Component.
  3. Create the Stylesheet for the Vue Component.
  4. Add API call to Vue.js Component.
  5. Display API Data In Vue.js Component.
  6. Styling the Vue.js Component.
Apr 20, 2021

How do you call props in Vue? ›

In Vue, props are custom attributes that you can register on any component. You define your data on the parent component and give it a value. Then, you go to the child component that needs that data and pass the value to a prop attribute. Therefore, the data becomes a property in the child component.

How to get user input in Vue js? ›

To get an input value in Vue, we can use the v-model directive to set up a two-way binding between the value and a variable. Every time the user changes the text in the input field, the text variable will be updated automatically. We can then use this variable to perform an action or display information.

What is the difference between ref and reactive in Vue? ›

ref() vs reactive() : Which should you use? The significant difference between ref() and reactive() is that the ref() function allows us to declare reactive state for primitives and objects, while reactive() only declares reactive state for objects.

How can you access and manipulate the DOM using JavaScript? ›

How to Manipulate Elements in the DOM
  1. let div = document.createElement('div');
  2. let text = node.textContent;
  3. element.innerHTML = 'new content';
  4. parentNode.appendChild(childNode);
  5. parentNode.insertBefore(newNode, existingNode);
  6. parentNode.replaceChild(newChild, oldChild);
  7. let childNode = parentNode.removeChild(childNode);
Nov 22, 2022

How many DOM elements are too many? ›

While browsers can handle larger DOM trees, they are optimized for a maximum of 32 elements deep. A large DOM tree can harm your page performance in multiple ways: Network efficiency and load performance.

How to get all DIV IDs in JavaScript? ›

Get IDs of all DIV elements

You can also get all DIV element IDs on web page, parent or child, in JavaScript. In this case, use the getElementByTagName() method. The getElementByTagName() takes a parameter in the form of the tagname. Here, the tagname would be DIV.

How do I find hidden elements in DOM? ›

Hidden elements are the elements that are present in the DOM but not visible on the webpage. Normally, hidden elements are defined by the CSS property style=display:none;. In case an element is a part of the form tag, it can be hidden by setting the attribute type to the value hidden.

What is the difference between DOM and element? ›

An HTML element is a component of an HTML document that tells web browser how to structure and interpret a part of the HTML document. The Document Object Model (DOM) is a programming interface for web documents.

How to find closest DOM element in js? ›

The closest() method searches up the DOM tree for elements which matches a specified CSS selector. The closest() method starts at the element itself, then the anchestors (parent, grandparent, ...) until a match is found. The closest() method returns null() if no match is found.

How do I get data from props in Vue? ›

To specify the type of prop you want to use in Vue, you will use an object instead of an array. You'll use the name of the property as the key of each property, and the type as the value. If the type of the data passed does not match the prop type, Vue sends an alert (in development mode) in the console with a warning.

Where should I fetch data in Vue? ›

Fetching After Navigation: perform the navigation first, and fetch data in the incoming component's lifecycle hook. Display a loading state while data is being fetched. Fetching Before Navigation: Fetch data before navigation in the route enter guard, and perform the navigation after data has been fetched.

What is the difference between computed properties and watchers in Vue? ›

Computed properties are used to calculate the value of a property based on some other conditions. Watchers, on the other hand, are not primarily used for changing the value of a property; instead, they are used to notify you when the value has changed and let you perform certain actions based on these changes.

How can I access one component data to another component? ›

For passing the data from the child component to the parent component, we have to create a callback function in the parent component and then pass the callback function to the child component as a prop. This callback function will retrieve the data from the child component.

How to pass id from one component to another in vue js? ›

How To Pass Data Between Components In Vue. js
  1. Using props share data from parent to child.
  2. Using Event Emitting custom events to share data from child to parent.
  3. Using EventBus to communicate between any components.
Jul 20, 2020

How do I access data from one component to another? ›

How to pass state data from one component to another in React. js
  1. class ParentComponent extends React.Component { state = { ...
  2. function ChildComponent(props) { return <div>{props.data}</div>; ...
  3. const MyContext = React. ...
  4. function ChildComponent() { ...
  5. class ParentComponent extends React. ...
  6. function ChildComponent(props) {

How do I connect components to Vue? ›

There are five ways to send the data from one component to another:
  1. Using Props (Parent to Child Communication)
  2. Using Events (Child to Parent Communication)
  3. Using Event Bus (Communication between any components)
  4. Using provide/inject (Parent to Child Communication)
  5. Using this. $refs (Parent to Child Communication)
Apr 24, 2021

How do I add a path to my library path? ›

Procedure. To edit the PATH system environment variable, click Environment Variable in Advance System Settings, and then select PATH. Click Edit, then specify the path to the directory containing the client libraries. Click OK.

How do I upload multiple files to Vue? ›

HTML
  1. <div id="app">
  2. <div>
  3. <h2>Select an image</h2>
  4. <input multiple type="file" @change="onFileChange">
  5. </div>
  6. <div v-if="images">
  7. <div v-for="(image, index) in images">
  8. <img :src="image" />

How do I import data into Vue? ›

Add CSV import to your Vue.

All you have to do is install @usecsv/vuejs for Vue. js 2 or @usecsv/vuejs3 for Vue. js 3, import the plugin, and template the HTML to display the import button. Uploaded data can be sent to your app as a frontend callback or backend webhook.

How do I access JSON data files? ›

Steps to open JSON files on Web browser (Chrome, Mozilla)
  1. Open the Web store on your web browser using the apps option menu or directly using this link.
  2. Here, type JSON View in search bar under the Extensions category.
  3. You will get the various extensions similar to JSON View to open the JSON format files.

How to access JSON property in JavaScript? ›

To access the JSON object in JavaScript, parse it with JSON. parse() , and access it via “.” or “[]”.

How do I fetch the JSON data from the JSON file using JS? ›

To fetch JSON from the server using the Fetch API, you need to use the JavaScript fetch() method and then call the response. json() method to get the JSON data as a JavaScript object. The response. json() method reads the data returned by the server and returns a Promise that resolves with a JSON object.

How do I fetch API data in Vue? ›

To use the Fetch API, we first need to create a Request object. This object will take an url and options object as parameters. The url parameter is where we specify the endpoint of the API that we want to call.

How to pass data from variable to JSON? ›

Three ways to pass the environment variables
  1. 1 Add a single quote and a double quote around the variable. $ curl -X POST https://requestbin.io/1bk0un41 -H "Content-Type: application/json" -d '{ "property1":"'"$TERM"'", "property2":"value2" }' ...
  2. 2 Escaping double quote. ...
  3. 3 Use a data generation function.

Why use axios instead of fetch? ›

Axios has built-in XSRF(Cross-Site Request Forgery) protection, while Fetch does not. Axios has the ability to intercept HTTP requests but Fetch, by default, does not. Axios allows canceling requests and request timeout but fetch does not.

How to call API through URL? ›

API URL. The API is accessed from the URL: http://www.domain.com/api/index.php.

How to call API in promise? ›

let promise = new Promise(function(resolve, reject) { let request = new XMLHttpRequest(); const url = `http://api.openweathermap.org/data/2.5/weather?q=${city}&appid=${process.env.API_KEY}`; request. addEventListener("loadend", function() { const response = JSON. parse(this. responseText); if (this.

How do I access props data? ›

How to use props without destructuring
  1. Step 1 - Pass in props as an argument. We did that in the first line of the code above: function Tool(props){} . ...
  2. Step 2 - Declare props variable(s) const name = props. ...
  3. Step 3 - Use variable(s) in JSX template. ...
  4. Step 4 - Pass data to props in the App component.
Nov 15, 2021

Can you pass props to router view Vue? ›

This makes testing easier and also makes the component more flexible since it decouples the component from the Vue Router. We can set the props property to true to pass in a route parameter as a prop. For static props, we can set an object as the value of props .

How do you pass props in a function call? ›

In order to to make props accessible in a function component you need to pass the props argument to the function and then you can access props by using the props object inside the function.

How to access input data in js? ›

To access the element the JavaScript method document. getElementById can be used. This function is expecting to get the ID of the element as an argument. You can then use the value property of the returned object to access the value of the input element.

How to access form inputs in js? ›

To access form fields, you can use DOM methods like getElementsByName() , getElementById() , querySelector() , etc. Also, you can use the elements property of the form object. The form. elements property stores a collection of the form elements.

How to collect user input in js? ›

In JavaScript, we use the prompt() function to ask the user for input. As a parameter, we input the text we want to display to the user. Once the user presses “ok,” the input value is returned. We typically store user input in a variable so that we can use the information in our program.

Is Vue performance better than React? ›

Vue. js offers higher performance speed, and many programmers say it is easier to learn than React. js. Its multiple customization features are also a factor that draws developers to Vue.

How do I make my property reactive in Vue? ›

We can create a reactive object or array with the reactive() function:
  1. js import { reactive } from 'vue' const state = reactive({ count: 0 }) ...
  2. template <button @click="increment"> {{ state. ...
  3. vue <script setup> import { reactive } from 'vue' const state = reactive({ count: 0 }) function increment() { state.

What does Vue do better than React? ›

Overall, Vue offers scaling projects and higher performance speed, but React. js has a better ecosystem, more templates, and additional tools. This is why teams on smaller projects where speed is a decisive factor, often opt for Vue, whereas React fits better to complex web platforms.

How do I access DOM nodes? ›

With the DOM, you can access every node in an XML document.
...
XML DOM - Accessing Nodes
  1. By using the getElementsByTagName() method.
  2. By looping through (traversing) the nodes tree.
  3. By navigating the node tree, using the node relationships.

Can I use DOM in Vue? ›

If a ref attribute is added to an HTML element in your Vue template, you'll then be able to reference that element or even a child element in your Vue instance. You can also access the DOM element directly; it is a read-only attribute and returns an object.

How do I access react DOM elements? ›

We access a DOM element using the current property of a reference created with the React. createRef() function. React will update this property with an actual DOM element after render and before update events. That means that we can access the DOM element in componentDidMount and componentDidUpdate functions.

How does Vue interact with the DOM? ›

Much like React, Vue. js utilizes a Virtual DOM that makes rendering your application's user interface lightning fast. A Virtual DOM is a representation or a copy of the actual DOM; it's also known as a “shadow DOM” and is rendered using JavaScript.

Which method is used to access DOM elements directly? ›

The getElementById Method

The most common way to access an HTML element is to use the id of the element.

How to extract data from DOM? ›

How to do it…
  1. Navigate to the menu tag whose class is nav-sections. Elements navDivTag = doc. getElementsByClass("nav-sections");
  2. Get the list of all menu tags that are owned by &#lt;a> . Elements list = navDivTag. get(0). ...
  3. Extract content from each Element class in the previous menu list. for(Element menu: list) {
Sep 12, 2013

How do I pass props to data in Vue? ›

In Vue, props are custom attributes that you can register on any component. You define your data on the parent component and give it a value. Then, you go to the child component that needs that data and pass the value to a prop attribute. Therefore, the data becomes a property in the child component.

What is the difference between DOM and virtual DOM in Vue? ›

You see that Vue virtual DOM is made of Vue components, which are JavaScript objects that extend the Vue instance. Vue uses a virtual DOM because of the sheer difference in speed and efficiency compared to the actual DOM. The virtual DOM is also smaller in size than the actual DOM and so is very efficient.

How to watch DOM element in JavaScript? ›

One way to watch for DOM changes in our JavaScript web app is to use the MutationObserver constructor. })(); to create the MutationObserver instance with a loop to append child elements to the body within the async function. We insert a new p element after 1 second 5 times.

How to select an element from DOM JavaScript? ›

There are 5 ways in which you can select elements in a DOM using selectors.
  1. getElementsByTagName()
  2. getElementsByClassName()
  3. getElementById()
  4. querySelector()
  5. querySelectorAll()

How do you manipulate DOM React? ›

React automatically updates the DOM to match your render output, so your components won't often need to manipulate it. However, sometimes you might need access to the DOM elements managed by React—for example, to focus a node, scroll to it, or measure its size and position.

Does Vue JS have two-way data binding? ›

One of the key benefits of Vue. js is its ability to provide a very simple reactive two-way data binding for custom form inputs and vue components.

How do you communicate between components in Vue? ›

There are five ways to send the data from one component to another:
  1. Using Props (Parent to Child Communication)
  2. Using Events (Child to Parent Communication)
  3. Using Event Bus (Communication between any components)
  4. Using provide/inject (Parent to Child Communication)
  5. Using this. $refs (Parent to Child Communication)
Apr 24, 2021

Is Vue one way or two-way data binding? ›

Vue's two-way binding system takes one of the trickiest parts of developing a web application, user input synchronization, and makes it dead simple with v-model. The v-model directive updates the template whenever the model changes and updates data model whenever the template changes.

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