In addition to allowing you to progressively integrate Vue into your applications, Vue also provides a progressive approach to writing markup. Like most frameworks, Vue lets you create reusable blocks of markup via components. As you work through this tutorial, you might want to keep the Vue guide and API documentation open in other tabs, so you can refer to them if you want more information on any sub topic. For a good but potentially biased comparison between Vue and many of the other frameworks, see Vue Docs: Comparison with Other Frameworks.
This allows you to start using Vue on existing sites, which is why Vue prides itself on being a progressive framework.
This is a great option when migrating an existing project using a library like JQuery to Vue. With this method, you can use a lot of the core features of Vue, such as the attributes, custom components, and data-management. However, this approach has some limitations. This will let you use advanced features of Vue and take advantage of bundlers like WebPack.
To make building apps with Vue easier, there is a CLI to streamline the development process. Note: If you don't have the above installed, find out more about installing npm and Node. The CLI will then give you a list of project configurations you can use. There are a few preset ones, and you can make your own.
These options let you configure things like TypeScript, linting, vue-router, testing, and more. To explore various features of Vue, we will be building up a sample todo list app. We'll begin by using the Vue CLI to create a new app framework to build our app into. Follow the steps below:. If you've never run the Vue CLI before, you'll get one more question — you'll be asked to choose a package manager.
You can use the arrow keys to select which one you prefer. The Vue CLI will default to this package manager from now on. Note: We've not gone over all of the options here, but you can find more information on the CLI in the Vue docs. If everything went successfully, the CLI should have created a series of files and directories for your project. The most significant ones are as follows:. Note: this is not the template for managing the layout of your application — this template is for managing static HTML that sits outside of your Vue app.
This is one great selling point, especially in the current ecosystem of JavaScript front-end frameworks and libraries that tend to alienate newcomers and also experienced developers that feel lost in the ocean of possibilities and choices.
Some people call Vue the new jQuery , because it easily gets in the application via a script tag, and gradually gains space from there. Think of it as a compliment, since jQuery dominated the Web in the past few years, and it still does its job on a huge number of sites. Vue was built by picking the best ideas of frameworks like Angular, React and Knockout, and by cherry-picking the best choices those frameworks made.
The two elephants in the room, when talking about web development, are React and Angular. How does Vue position itself relative to those two big and popular frameworks? It was born out of a need to create more performant applications. Vue picked some of the Angular templating syntax, but removed the opinionated, complex stack that Angular required, and made it very performant. The new Angular Angular 2.
It also requires a buy-in to TypeScript which not all developers enjoy using or want to learn. What about React? But Vue implements it with some sort of automatic dependency management. This tracks which components are affected by a change of the state so that only those components are re-rendered when that state property changes.
In React, on the other hand, when a part of the state that affects a component changes, the component will be re-rendered. By default all its children will be re-rendered as well. To avoid this you need to use the shouldComponentUpdate method of each component and determine if that component should be re-rendered.
This gives Vue a bit of an advantage in terms of ease of use, and out of the box performance gains. One big difference with React is JSX. Vue templates are very similar to Mustache and Handlebars although they differ in terms of flexibility.
As such, they are more familiar to developers that already used frameworks like Angular and Ember. The official state management library, Vuex , follows the Flux architecture and is somewhat similar to Redux in its concepts.
Again, this is part of the positive things about Vue, which saw this good pattern in React and borrowed it for its ecosystem. And while you can use Redux with Vue, Vuex is specifically tailored for Vue and its inner workings. Vue is flexible, but the fact that the core team maintains two packages that are very important for any web app like routing and state management makes it a lot less fragmented than React.
For example: vue-router and vuex are key to the success of Vue. Since they are official, they are the canonical go-to libraries for their niche but you can choose to use what you like, of course. I put the script tags at the end of the body so that they are executed in order after the DOM is loaded.
What this code does is instantiate a new Vue app, linked to the example element as its template. Then, it associates that template to the data object. That is a special object that hosts the data we want Vue to render. CodePen is a little different from using a plain HTML file, and you need to configure it to point to the Vue library location in the Pen settings:. What is the Vue CLI? A simpler way, without having to install anything, is to go to CodeSandbox.
The link opens the Vue CLI default application. CodeSandbox is a cool code editor that allows you build apps in the cloud. You can use any npm package, and can easily integrate with Zeit Now for an easy deployment and with GitHub to manage versioning. Beside package. Next, we create the Vue instance, by assigning it to the DOM element identified by app , which we defined in index.
This might seem weird at first, but Single File Components are a great way to create self-contained components that have all they need in a single file. This component is going to be referenced in our component. We are going to output this code. Vue will automatically insert that component inside this placeholder. Remember above we talked about CSS in App.
You can easily determine it by looking at the style tag. CodeSandbox has a cool preview functionality. You can run the app and edit anything in the source to have it immediately reflected in the preview. CodeSandbox is very cool for online coding and working without having to setup Vue locally.
A great way to work locally is by setting up the Vue CLI command line interface. Also, how do we setup a Vue CLI-based project locally? Note: There is a huge rework of the CLI going on right now, going from version 2 to 3. Its main goal is to make sure all the tools you need are working along, to perform what you need, and abstracts away all the nitty-gritty configuration details that using each tool in isolation would require.
After you create and configure the app, it acts as a runtime dependency tool, built on top of Webpack. You need to pick a preset. By default, there is one preset that provides Babel and ESLint integration:. Press space to enable one of the things you need, and then press enter to go on.
Next up: testing. Vue CLI asks me where to put all the configuration: in the package. I chose the latter. This is the last thing it asks me, and then it goes on to download the dependencies and create the Vue app:. Vue CLI has created the app for us, and we can go in the example folder and run yarn serve to start up our first app in development mode:.
The starter example application source contains a few files, including package. This is where all the CLI commands are defined, including yarn serve , which we used a minute ago.
The other commands are. Notice the master word in the lower-left corner of VS Code? So we can jump right in, change things, and we know what we changed:. This is pretty cool. Presets are stored in the. As you can see from reading the configuration, a preset is basically a collection of plugins, with some optional configuration.
All those plugins are used in the latest version available. You can force Vue CLI to use a specific version by passing the version property:.
This is useful if a new version has a breaking change or a bug, and you need to wait a little bit before using it. A preset can be stored in GitHub or on other services by creating a repository that contains a preset. Extracted from the above, I made a sample preset which contains this configuration:. Vue CLI by default uses main. You can still have access to it by calling vue inspect :. This is a friendly reminder to install the Vue Devtools Extension.
Any popular framework has its own devtools extension, which generally adds a new panel to the browser developer tools that is much more specialized than the ones that the browser ships by default. In this case, the panel will let us inspect our Vue application and interact with it. This tool will be an amazing help when building Vue apps.
This makes sure no one can use them to interact with your production app — and will make Vue more performant, because it does not have to care about the Dev Tools. Safari, Edge and other browsers are not supported with a custom extension, but using the standalone application you can debug a Vue. Go through the installation process:.
The Vue. If the page does not have a Vue. If Vue. The icon does nothing except show us that there is a Vue. You can find the Firefox dev tools extension in the Mozilla Add-ons store. As with Chrome, a grayed icon shows up in the toolbar. It will automatically connect to the app. As mentioned, the Vue DevTools can be activated by opening the Developer Tools in the browser and moving to the Vue panel. When the Vue DevTools panel is open, we can navigate the components tree.
When we choose a component from the list on the left, the right panel shows the props and data it holds:. You can hover over any component in the page with the mouse, click it, and it will be opened in the devtools. Any user component not framework-level components has a button that opens it in your default editor. Very handy. Visual Studio Code is one of the most used code editors in the world right now.
Editors have, like many software products, a cycle. The cool thing about being popular is that people dedicate a lot of time to building plugins for everything they can imagine.
Clicking the Install button will trigger the installation panel in VS Code:. Without Vetur, a. VS Code by default cannot recognize this kind of situation, and Vetur provides syntax highlighting for each kind of code you use. As with syntax highlighting, since VS Code cannot determine the kind of code contained in a part of a.
Snippets are pieces of code we can add to the file, provided by specialized plugins. IntelliSense is also enabled by Vetur, for each different language, with autocomplete:. In addition to enabling custom snippets, Vetur provides its own set of snippets. Each one creates a specific tag template, script, or style with its own language:.
Note: scoped in the above list means that it applies to the current component only. Vetur provides automatic support for code formatting to format the whole file upon save — in combination with the "editor.
You can choose to disable automatic formatting for some specific languages by setting the vetur. To change one of those settings, just start searching for the string, and override what you want in the user settings on the right panel. It uses your Prettier configuration to determine your preferences. Components are single, independent units of an interface. They can have their own state, markup, and style. The third is by using local components. These are components that are only accessible by a specific component, and not available elsewhere great for encapsulation.
Using new Vue or Vue. Or maybe Vue is used in all pages, but the server is rendering the layout, and you serve the HTML to the client, which then loads the Vue application you build. You instantiate Vue by mounting it on a DOM element. Other components used in the application are initialized using Vue. Such a component allows you to define a tag — with which you can embed the component multiple times in the application — and specify the output of the component in the template property:.
See on JSFiddle. What are we doing? We are initializing a Vue root component on app , and inside that, we use the Vue component user-name , which abstracts our greeting to the user. The component accepts a prop, which is an attribute we use to pass data down to child components. In the Vue. This gives the component a name. You can write the name in 2 ways here. The first is the one we used, called kebab-case. The second is called PascalCase, which is like camelCase, but with the first letter capitalized:.
Vue automatically creates an alias internally from user-name to UserName , and vice versa, so you can use whatever you like. Any component created using Vue. You can encapsulate components locally by assigning an object that defines the component object to a variable:. You can write the component in the same file, but a great way to do this is to use JavaScript modules:. A child component can be added multiple times.
Each separate instance is independent of the others:. All of this is possible thanks to the use of Webpack. The Vue CLI makes this very easy and supported out of the box. Since Single File Components rely on Webpack, we get for free the ability to use modern Web features. Your CSS can be defined using SCSS or Stylus, the template can be built using Pug, and all you need to do to make this happen is to declare to Vue which language preprocessor you are going to use.
If you omit scoped , the CSS you define will be global. But adding the scoped tag, Vue automatically adds a specific class to the component, unique to your app, so the CSS is guaranteed to not leak out to other components.
Maybe your JavaScript is huge because of some logic you need to take care of. What if you want to use a separate file for your JavaScript? This is different, because it uses an arrow function.
Arrow functions are fine until we need to access a component method. This is an issue if we need to make use of this , and such property is not bound to the component using arrow functions.
This is using the CommonJS syntax and it works as well. Add a comment. ScottyG ScottyG 2, 1 1 gold badge 27 27 silver badges 40 40 bronze badges.
Please simply try type npm v vue in terminal to check the version of Vue. Tiahin Tiahin 2 2 silver badges 2 2 bronze badges. Aakash Aakash If you want to check the current version of Vue installed in your machine use vue --version If you want to check the Vue installed on the project then use npm list grep vue. Unheilig Thanks, VenkataSaiKatepalli, the second one was quite useful to me.
The first command may be to check the vue cli version I think. Shweta Shweta 71 1 1 silver badge 4 4 bronze badges. There are few ways to check vue version: npm v vue run this on the terminal Check package.
White Tiger White Tiger 31 5 5 bronze badges. You can also type to check the Vuejs version vue --version. Mayur Kapadia Mayur Kapadia 81 3 3 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. If you open up your JavaScript console again and enter app2. Go ahead and enter app3. You should see the message disappear. This example demonstrates that we can bind data to not only text and attributes, but also the structure of the DOM.
There are quite a few other directives, each with its own special functionality. For example, the v-for directive can be used for displaying a list of items using the data from an Array:. In the console, enter app4. You should see a new item appended to the list. To let users interact with your app, we can use the v-on directive to attach event listeners that invoke methods on our Vue instances:.
Note that in this method we update the state of our app without touching the DOM - all DOM manipulations are handled by Vue, and the code you write is focused on the underlying logic.
Vue also provides the v-model directive that makes two-way binding between form input and app state a breeze:. If we think about it, almost any type of application interface can be abstracted into a tree of components:. In Vue, a component is essentially a Vue instance with pre-defined options.
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