Kako stvoriti Vue.js aplikaciju pomoću komponenata s jednom datotekom, bez CLI-ja.

Razumijevanje Vue-ovih komponenata za jednu datoteku (SFC-ovi) i Node Package Manager (NPM) bit će korisno za ovaj članak.

Sučelje naredbenog retka okvira ili CLI preferirana je metoda za skeniranje projekta. Pruža polazište datotekama, mapama i konfiguraciji. Ova skela također pruža proces razvoja i izrade. Proces razvoja pruža način da vidite ažuriranja koja se javljaju dok uređujete svoj projekt. Proces gradnje stvara konačnu verziju datoteka koje će se koristiti u proizvodnji.

Instaliranje i pokretanje Vue.js ("Vue") može se izvršiti s oznakom skripte koja upućuje na mrežu za isporuku sadržaja Vue (CDN). Nije potreban nikakav postupak gradnje ili razvoja. Ali ako koristite Vue komponente s jednom datotekom (SFC), te datoteke morate pretvoriti u nešto što preglednik može razumjeti. Datoteke treba pretvoriti u jezik za označavanje hiperteksta (HTML), kaskadne tabele stilova (CSS) i JavaScript (JS). U tom se slučaju mora koristiti proces razvoja i izrade.

Umjesto da se oslanjamo na Vue CLI kako bi skenirao naš projekt i pružio nam proces razvoja i izrade, mi ćemo graditi projekt od nule. Stvorit ćemo vlastiti proces razvoja i gradnje pomoću Webpacka.

Što je Webpack?

Webpack je snop modula. Spaja kôd iz više datoteka u jednu. Prije Webpacka, korisnik je uključio oznaku skripte za svaku JavaScript datoteku. Iako preglednici polako podržavaju ES6 module, Webpack je i dalje preferirani način izrade modularnog koda.

Osim što je paket paketa modula, Webpack također može transformirati kod. Na primjer, Webpack može potrajati moderne JavaScript (ECMAScript 6+) i pretvoriti ga u ECMAScript 5. Dok Webpack pakete kod sebe, ona transformira kod sa točkovima i dodataka. Zamišljajte loader i dodatke kao dodatke za Webpack.

Webpack i Vue

Komponente s jednom datotekom omogućuju nam izgradnju cijele komponente (struktura, stil i funkcija) u jednoj datoteci. I većina uređivača koda nudi isticanje sintakse i povezivanje za ove SFC-ove.

Primijetite da datoteka završava s .vue. Preglednik ne zna što učiniti s tim proširenjem. Webpack, pomoću alata za učitavanje i dodataka, pretvara ovu datoteku u HTML, CSS i JS koje preglednik može potrošiti.

Projekt: Izgradite Hello World Vue aplikaciju pomoću komponenata od jedne datoteke.

Korak 1: Stvorite strukturu projekta

Najosnovniji Vue projekt uključivat će HTML, JavaScript i Vue datoteku (datoteka koja završava s .vue ). Te ćemo datoteke smjestiti u mapu pod nazivom src. Izvorna mapa pomoći će nam da odvojimo kod koji pišemo od koda koji će Webpack na kraju izgraditi.

Budući da ćemo koristiti Webpack, trebamo konfiguracijsku datoteku Webpack.

Uz to ćemo koristiti kompajler nazvan Babel. Babel nam omogućuje da napišemo ES6 kod koji zatim kompajlira u ES5. Babel je jedna od onih "dodataka" za Webpack. Babel također treba konfiguracijsku datoteku.

Konačno, budući da koristimo NPM, imat ćemo i mapu node_modules i datoteku package.json. Oni će se automatski stvoriti kad inicijaliziramo svoj projekt kao NPM projekt i počnemo instalirati naše ovisnosti.

Za početak stvorite mapu pod nazivom hello-world. Iz naredbenog retka prijeđite na taj direktorij i pokrenite npm init. Slijedite upute na zaslonu za izradu projekta. Zatim stvorite ostatak mapa (osim node_modules) kako je gore opisano. Struktura vašeg projekta trebala bi izgledati ovako:

Korak 2: Instalirajte ovisnosti

Evo kratkog pregleda ovisnosti koje koristimo:

vue : Okvir JavaScript

vue-loader i vue-template-compiler : Koristi se za pretvaranje naših Vue datoteka u JavaScript.

webpack : Alat koji će nam omogućiti da svoj kod proslijedimo kroz neke transformacije i združimo ga u jednu datoteku.

webpack-cli: Potrebno za pokretanje naredbi Webpack.

webpack-dev-server : Iako nije potreban za naš mali projekt (budući da nećemo podnositi nikakve HTTP zahtjeve), i dalje ćemo "služiti" našem projektu s razvojnog poslužitelja.

babel-loader : Transformirajte naš ES6 kod u ES5. (Potrebna mu je pomoć iz sljedeće dvije ovisnosti.)

@ babel / core i @ babel / preset-env : Babel sam po sebi ne čini ništa vašem kodu. Ova dva „dodatka“ omogućit će nam da transformiramo svoj ES6 kôd u ES5 kôd.

css-loader: Uzima CSS koji upisujemo u svoj.vuedatoteke ili bilo koji CSS koji bismo mogli uvesti u bilo koju od naših JavaScript datoteka i riješiti put do tih datoteka. Drugim riječima, shvatite gdje je CSS. Ovo je još jedan loader koji sam po sebi neće učiniti puno. Trebamo sljedeći loader da bismo zapravo nešto učinili sa CSS-om.

vue-style-loader : Uzmite CSS koji smo dobili od našeg css-loaderi ubrizgajte ga u našu HTML datoteku. To će stvoriti i ubrizgati stilsku oznaku u glavu našeg HTML dokumenta.

html-webpack-plugin : Uzmite naš index.html i u glavu ubrizgajte našu priloženu JavaScript datoteku. Zatim kopirajte ovu datoteku udistmapu.

rimraf : Omogućuje nam, iz naredbenog retka, brisanje datoteka. To će nam dobro doći kada svoj projekt gradimo više puta. Ovo ćemo upotrijebiti za brisanje svih starih gradnji.

Instalirajmo ove ovisnosti sada. Iz naredbenog retka pokrenite:

npm install vue vue-loader vue-template-compiler webpack webpack-cli webpack-dev-server babel-loader @babel/core @babel/preset-env css-loader vue-style-loader html-webpack-plugin rimraf -D

Napomena: "-D" na kraju svaku ovisnost označava kao razvojnu ovisnost u našem paketu.json. Sve zavisnosti grupiramo u jednu datoteku, tako da za naš mali projekt nemamo proizvodne ovisnosti.

Korak 3: Stvorite datoteke (osim naše konfiguracijske datoteke Webpack).

 {{ message }} export default { data() { return { message: 'Hello World', }; }, };   #app { font-size: 18px; font-family: 'Roboto', sans-serif; color: blue; } 
  Vue Hello World 
import Vue from 'vue'; import App from './App.vue'; new Vue({ el: '#app', render: h => h(App), });
module.exports = { presets: ['@babel/preset-env'], }

Up to this point, nothing should look too foreign. I’ve kept each file very basic. I’ve only added minimal CSS and JS to see our workflow in action.

Step 4: Instructing Webpack what to do

All the configuration Webpack needs access to is now present. We need to do two final things: Tell Webpack what to do and run Webpack.

Below is the Webpack configuration file (webpack.config.js). Create this file in the projects root directory. Line-by-line we’ll discuss what is occurring.

const HtmlWebpackPlugin = require('html-webpack-plugin'); const VueLoaderPlugin = require('vue-loader/lib/plugin'); module.exports = { entry: './src/main.js', module: { rules: [ { test: /\.js$/, use: 'babel-loader' }, { test: /\.vue$/, use: 'vue-loader' }, { test: /\.css$/, use: ['vue-style-loader', 'css-loader']}, ] }, plugins: [ new HtmlWebpackPlugin({ template: './src/index.html', }), new VueLoaderPlugin(), ] };

Lines 1 and 2: We are importing the two plugins we use below. Notice, our loaders don’t normally need to be imported, just our plugins. And in our case, thevue-loader (which we use in line 9) also needs a plugin to work (however, Babel, for example, does not).

Line 4: We export our configuration as an object. This gives us access to it when we run the Webpack commands.

Line 5: This is our entry module. Webpack needs a place to start. It looks in our main.js file and then starts to comb through our code from that point.

Line 6 and 7: This is the module object. Here, we primarily pass in an array of rules. Each rule tells Webpack how to handle certain files. So, while Webpack uses the entry point of main.js to start combing through our code, it uses the rules to transform our code.

Line 8 (rule): This rule instructs Webpack to use the babel-loader on any files which end with .js. Remember, Babel will transform ES6+ to ES5.

Line 9 (rule): This rule instructs Webpack to use vue-loader(and don’t forget the associated plugin on line 17) to transform our .vue files into JavaScript.

Line 10 (rule): Sometimes we want to pass a file through two loaders. Counterintuitively, Webpack will pass the file from right to left instead of left to right. Here we are using two loaders and saying to Webpack: “get my CSS from my Vue file or any JavaScript files(css-loader) and inject it into my HTML as a style tag (vue-style-loader).

Lines 11 and 12: Close out our rules array and module object.

Lines 13: Create a plugins array. Here we will add the two plugins we need.

Line: 14 -16 (plugin): The HtmlWebpackPlugin takes the location of our index.html file and adds our bundled JavaScript file to it via a script tag. This plugin will also copy the HTML file to our distribution folder when we build our project.

Line 17 (plugin): The VueLoaderPlugin works with our vue-loader to parse our .vue files.

Line 18: Close out the plugins array.

Line 19: Close out the Webpack object that we are exporting.

Step 5: Setting up our package.json file so we can run Webpack

Our configuration is complete, now we want to see our application. Ideally, as we make changes to our application, the browser would update automatically. This is possible with webpack-dev-server.

Delete the test script in our package.json file, and replace it with a script to serve our application:

 { "name": "hello-world", "version": "1.0.0", "description": "", "main": "main.js", "scripts": { "serve": "webpack-dev-server --mode development" }, "author": "", "license": "ISC", "devDependencies": { "@babel/core": "^7.1.6", "@babel/preset-env": "^7.1.6", "babel-loader": "^8.0.4", "css-loader": "^1.0.1", "html-webpack-plugin": "^3.2.0", "rimraf": "^2.6.2", "vue": "^2.5.17", "vue-loader": "^15.4.2", "vue-style-loader": "^4.1.2", "vue-template-compiler": "^2.5.17", "webpack": "^4.26.0", "webpack-cli": "^3.1.2", "webpack-dev-server": "^3.1.10" }, "dependencies": {} }

The name of this command is your choice. I chose to call mine serve since we will be serving our application.

From our terminal or command line, we can run npm run serve and that in turn will run webpack-dev-server --mode development .

The --mode development is what’s called a flag or option. We haven’t talked about this, but it essentially instructs Webpack that you are in development mode. We can also pass in --mode production which we will do when we build our project. These aren’t necessarily required for Webpack to work. Without these, you will get a warning message telling you to provide a mode when you run Webpack .

I say “necessarily required” because Webpack will minimize our code in production mode but not in development. So, don’t think those commands don’t do anything–they do.

Let’s run npm run serve and see what happens.

When we run npm run serve we get some output in our terminal. And, if everything goes well:

And if we scroll up a bit:

Point your browser to //localhost:8080. You will see your Blue Hello World message in Roboto font.

Now, let’s update the project and change the message to Hello Universe. Notice that the webpage refreshes automatically. That’s great, right? Can you think of a downside?

Let’s change the application just a bit and include an input which we will bind a variable to (with v-model). We will output the variable in an

tag below the input. I’ve also updated the styling section to style the message now. Our App.vuefile should look like this:

{{ message }}

export default { data() { return { message: 'Hello world!', }; }, }; .message { font-size: 18px; font-family: 'Roboto', sans-serif; color: blue; }

When we serve our application, we will have an input with a message of Hello World below it. The input is bound to the message variable, so as we type, we change the

content. Go ahead, type into the input to change the

content.

Now go back to your editor, and below the

tag, add the following:

Some Other Message

Save your App.vue and watch what happens.

The h2 we just updated by typing in our input reverted back to Hello World. This is because the browser actually refreshes, and the script tag and page are loaded again. In other words, we were not able to maintain the state of our application. This may not seem like a big deal, but as you are testing your application and adding data to it, it will be frustrating if your app “resets” every time. Fortunately, Webpack offers us a solution called Hot Module Replacement.

The hot module replacement is a plugin provided by Webpack itself. Up until this point, we have not used the Webpack object itself in our configuration file. However, we will now import Webpack so we can access the plugin.

In addition to the plugin, we will pass one additional option to Webpack, the devServer option. In that option, we will set hot to true. Also, we will make an (optional) update to our build workflow: We will open the browser window automatically when we run npm run serve. We do this by setting open to true which is also inside the devServer option.

const HtmlWebpackPlugin = require('html-webpack-plugin'); const VueLoaderPlugin = require('vue-loader/lib/plugin'); const webpack = require('webpack'); module.exports = { entry: './src/main.js', module: { rules: [ { test: /\.js$/, use: 'babel-loader' }, { test: /\.vue$/, use: 'vue-loader' }, { test: /\.css$/, use: ['vue-style-loader', 'css-loader']}, ] }, devServer: { open: true, hot: true, }, plugins: [ new HtmlWebpackPlugin({ template: './src/index.html', }), new VueLoaderPlugin(), new webpack.HotModuleReplacementPlugin(), ] };

Notice that we’ve imported Webpack so we could access the hotModuleReplacementPlugin. We’ve added that to the plugins array, and then told Webpack to use it with hot: true. We open the browser window automatically when we serve the application with open: true.

Run npm run serve:

The browser window should open, and if you open your dev tools, you should notice a slight change in the output. It now tells us hot module replacement is enabled. Let’s type in our input to change the

content. Then, change theh3 tag to read: One More Message.

Save your file and notice what happens.

The browser doesn't refresh, but our

change is reflected! The message we typed in the input remains, but the h3 updates. This allows our application to keep it’s state while we edit it.

Step 7: Building our project

So far, we’ve served our application. But, what if we want to build our application so we can distribute it?

If you noticed, when we serve our application, no files are created. Webpack creates a version of these files that only exist in temporary memory. If we want to distribute our Hello World app to our client, we need to build the project.

This is very simple. Just like before, we will create a script in our package.json file to tell Webpack to build our project. We will use webpack as the command instead of webpack-dev-server. We will pass in the --mode production flag as well.

We will also use the rimraf package first to delete any previous builds we may have. We do this simply by rimraf dist.

dist is the folder Webpack will automatically create when it builds our project. “Dist” is short for distribution–i.e. we are “distributing” our applications code.

The rimraf dist command is telling therimraf package to delete the dist directory. Make sure you don’t rimraf src by accident!

Webpack also offers a plugin that will accomplish this cleaning process called clean-webpack-plugin. I chose dist show an alternative way.

Our package.json file should look like this:

{ "name": "hello-world", "version": "1.0.0", "description": "", "main": "main.js", "scripts": { "clean": "rimraf dist", "build": "npm run clean && webpack --mode production", "serve": "webpack-dev-server --mode development" }, "author": "", "license": "ISC", "devDependencies": { "@babel/core": "^7.1.6", "@babel/preset-env": "^7.1.6", "babel-loader": "^8.0.4", "css-loader": "^1.0.1", "html-webpack-plugin": "^3.2.0", "rimraf": "^2.6.2", "vue": "^2.5.17", "vue-loader": "^15.4.2", "vue-style-loader": "^4.1.2", "vue-template-compiler": "^2.5.17", "webpack": "^4.26.0", "webpack-cli": "^3.1.2", "webpack-dev-server": "^3.1.10" }, "dependencies": {} }

There are three things to notice:

  1. I’ve created a separate clean script so we can run it independently of our build script.
  2. npm run build will call the independent clean script we’ve created.
  3. I have && between npm run clean and webpack. This instruction says: “run npm run clean first, then run webpack”.

Let’s build the project.

npm run build

Webpack creates a dist directory, and our code is inside. Since our code makes no HTTP requests, we can simply open our index.html file in our browser and it will work as expected.

If we had code that was making HTTP requests, we would run into some cross-origin errors as we made those requests. We would need to run that project from a server for it to work.

Let’s examine the index.html that Webpack created in the browser and the code editor.

If we open it in our editor or take a look at the source code in our dev tools you will see Webpack injected the script tag. In our editor though, you won’t see the styles because the style tag is injected dynamically at runtime with JavaScript!

Also, notice our development console information is no longer present. This is because we passed the --production flag to Webpack.

Conclusion

Understanding the build process behind the frameworks you use will help you to better understand the framework itself. Take some time to try to build an Angular, React or another Vue Project without the use of the respective CLIs. Or, just build a basic three-file site (index.html, styles.css, and app.js), but use Webpack to serve and build a production version.

Thanks for reading!

woz