Joseph  Norton

Joseph Norton

1671094383

Build a Single-Page Application with Vue.js and Laravel

In this tutorial, you'll learn how to build a single-page application using Laravel and Vue.js. Create a straightforward user authentication and to-do application using Vue and Laravel when compared to the traditional PHP/Vue combo — which can require a lot more setup work.

With its clean syntax, expressiveness, and many other qualities, Laravel is one of the most popular PHP frameworks used by developers.

With its clean syntax and expressiveness, along with many other qualities, Laravel is one of the most popular PHP frameworks used by developers.

Before Laravel UI was launched, one of its key features was default support for Vue.js from Laravel v5.3 to v6. Vue is a modern JavaScript frontend framework used to create user interfaces.

In this article, we will demonstrate how you can build a single-page application using Laravel and Vue.

Table of contents:

  • Why are Laravel and Vue good together?
  • What is an SPA? (single-page application)
  • Project setup
  • Vue routing

Why are Laravel and Vue good together?

Here are some of the key advantages of using both Laravel with Vue to create a full-stack workflow for your projects:

  • The source code is combined into one project, rather than having separate projects for the backend and frontend
  • Setup and configuration are simple
  • A single deployment can handle both frameworks together

What is an SPA? (single-page application)

A single-page application (SPA for short) dynamically loads new data from a web server to a webpage without needing to refresh the entire page.

Examples of popular websites that use SPA include gmail.com and youtube.com — in other words, SPAs are ubiquitous to a large extent. The majority of admin dashboards that you might work with on a daily basis are created using SPAs.

Benefits of SPAs:

  • User experience is more flexible
  • Caches data in the browser
  • Quick load time

Disadvantages of SPAs:

  • Can compromise SEO (search engine optimization)
  • Potential security issues
  • Consumes a lot of browser resources

Project setup

This post will demonstrate how to develop a to-do app that allows users to register for an account and add tasks.

For this tutorial, Laravel 9 is being used, which calls for PHP 8.1 and Vue 3; we also need to have PHP and NGINX installed.

Let’s get started with the following command:

composer create-project --prefer-dist laravel/laravel laravel-vue-demo

Next, we will install the JavaScript dependencies.

npm install

We must install a few packages before we can add Vue to our project.

In addition, plugin-vue must be installed, as Laravel 9 ships with Vite, rather than webpack-mix, which was the previous Laravel bundler for JavaScript. Let’s do that now:

npm install vue@next vue-loader@next @vitejs/plugin-vue

Open the file called vite.config.js and add vue() to the config:

import { defineConfig } from 'vite';
import laravel from 'laravel-vite-plugin';
import vue from '@vitejs/plugin-vue'

export default defineConfig({
    plugins: [
        vue(),
        laravel([
            'resources/css/app.css',
            'resources/js/app.js',
        ]),
    ],
});

Edit the app.js file and the snippet for the Vue 3 app bootstrap:

require('./bootstrap');

import {createApp} from 'vue'

import App from './App.vue'

createApp(App).mount("#app")

Create a file called App.vue and add the following:

<template>
  <h1> Hello, Vuejs with Laravel </h1>
</template>
<script>
export default {
  setup() {

   }
}
</script>

Finally, open the welcome.blade.php file located in the resources/views folder and add the following:

<!DOCTYPE html>
<html>
<head>
 ....
        @vite('resources/css/app.css')
</head>
<body>
  <div id="app"></div>
  @vite('resources/js/app.js')
</body>
</html>

To preview our app, we need to start our Vue app and Laravel server on two different terminals/command lines:

npm run dev


php artisan serve

App Preview Local Host

To build our to-do app, we need to create some more files. Vue will create multiple pages, principally:

  • A login page
  • A registration page
  • A home page

To communicate with the Laravel endpoints, we need to install Axios:

npm install axios

Vue routing

Using the vue-router package, there are various routing strategies that may be used in Vue; these strategies are also known as history modes.

When a user requests routes like http://localhost:8000/home — which will return a 404 error when the page is refreshed — we can rely on Laravel to detect any fallback routes and then serve the Blade file that contains our app.

For this reason, we will use HTML5 mode:

Route::get('/{vue_capture?}', function() {
    return view('welcome');
})->where('vue_capture', '[\/\w\.-]*');import {createRouter, createWebHistory} from 'vue-router';

const router = createRouter({
    history: createWebHistory(),
    routes: [
        {
            path: '/',
            component: () => import('./pages/Login.vue')
        },
        {
            path: '/register',
            component: () => import('./pages/Register.vue')
        },
        {
            path: '/home',
            component: () => import('./pages/Home.vue')
        }
    ],
})

Due to the simplicity of the project, we are essentially handling authentication for the login page using Laravel Sanctum, and then we save our token in the local storage.

For other requests to be successful, the token is joined to the header, which will allow the user making the request to be identified by Laravel.

Here is what our login page will look like:

Login Page Example

And here is what our registration page will look like:

Registration Page Example Screenshot

Finally, here are the associated code blocks for both:

<!--Login.vue-->
<template>
    <div class="mx-auto w-4/12 mt-10 bg-blue-200 p-4 rounded-lg">
        <div
            class="bg-white shadow-lg rounded-lg px-8 pt-6 pb-8 mb-2 flex flex-col"
        >
            <h1 class="text-gray-600 py-5 font-bold text-3xl"> Login </h1>
            <ul class="list-disc text-red-400" v-for="(value, index) in errors" :key="index" v-if="typeof errors === 'object'">
                <li>{{value[0]}}</li>
            </ul>
            <p class="list-disc text-red-400" v-if="typeof errors === 'string'">{{errors}}</p>
            <form method="post" @submit.prevent="handleLogin">
            <div class="mb-4">
                <label
                    class="block text-grey-darker text-sm font-bold mb-2"
                    for="username"
                >
                    Email Address
                </label>
                <input
                    class="shadow appearance-none border rounded w-full py-2 px-3 text-grey-darker"
                    id="username"
                    type="text"
                    v-model="form.email"
                    required
                />
            </div>
            <div class="mb-4">
                <label
                    class="block text-grey-darker text-sm font-bold mb-2"
                    for="password"
                >
                    Password
                </label>
                <input
                    class="shadow appearance-none border border-red rounded w-full py-2 px-3 text-grey-darker mb-3"
                    id="password"
                    type="password"
                    v-model="form.password"
                    required
                />
            </div>
            <div class="flex items-center justify-between">
                <button
                    class="bg-blue-500 hover:bg-blue-900 text-white font-bold py-2 px-4 rounded"
                    type="submit"
                >
                    Sign In
                </button>
                <router-link
                    class="inline-block align-baseline font-bold text-sm text-blue hover:text-blue-darker"
                    to="register"
                >
                    Sign Up
                </router-link>
            </div>
            </form>
        </div>
    </div>
</template>export default {
    setup() {
        const errors = ref()
        const router = useRouter();
        const form = reactive({
            email: '',
            password: '',
        })
        const handleLogin = async () => {
            try {
                const result = await axios.post('/api/auth/login', form)
                if (result.status === 200 && result.data && result.data.token) {
                    localStorage.setItem('APP_DEMO_USER_TOKEN', result.data.token)
                    await router.push('home')
                }
            } catch (e) {
                if(e && e.response.data && e.response.data.errors) {
                    errors.value = Object.values(e.response.data.errors)
                } else {
                    errors.value = e.response.data.message || ""
                }
            }
        }

        return {
            form,
            errors,
            handleLogin,
        }
    }
}

The Vue Home view/page handles all to-do actions such as creating, deleting, updating, and listing to-dos. All the actions make requests to the endpoints with the user token for authorization via Axios.

Let’s take a look at what they will look like, followed by the associated snippets:

Todo Example Screenshot

Todo Example Screenshot

<!-- Home -->
<template>
    <div class="w-6/12 p-10 mx-auto">
        <div class="flex justify-between">
            <h1 class="text-2xl"> Todo </h1>
            <span class="capitalize">Welcome {{ user && user.name }}, <button
                class="text-orange-500 underline hover:no-underline rounded-md"
                @click="handleLogout">Logout</button></span>
        </div>
        <input type="text" class="p-2 w-64 border rounded-md" v-model="todo" placeholder="Enter your todo"/>
        <button class="bg-blue-600 text-white px-5 py-2 rounded-md ml-2 hover:bg-blue-400" @click="addTodo">Add</button>
        <Loader v-if="isLoading"/>
        <ul class="border-t mt-3 cursor-pointer">
            <li :class="`py-3 border-b text-gray-600 ${val.has_completed ? 'line-through' : ''}`"
                v-for="(val, idx) in todos" :key="idx">
                <input type="checkbox" :checked="val.has_completed" @click="checked(idx)"/>
                <span @click="checked(val, idx)" class="pl-3">{{ val.title }} </span>
                <button class="float-right bg-red-400 px-2 text-white font-bold rounded-md hover:bg-red-600"
                        @click="deleteTodo(val, idx)">&times;
                </button>
            </li>
        </ul>
    </div>
</template>setup() {
    const todo = ref('')
    const todos = ref([])
    const user = ref()
    const isLoading = ref()

    let router = useRouter();
    onMounted(() => {
        authentication()
        handleTodos()
    });

    const authentication = async () => {
        isLoading.value = true
        try {
            const req = await request('get', '/api/user')
            user.value = req.data
        } catch (e) {
            await router.push('/')
        }
    }

    const handleTodos = async () => {
        try {
            const req = await request('get', '/api/todos')
            todos.value = req.data.data
        } catch (e) {
            await router.push('/')
        }
        isLoading.value = false
    }

    const handleNewTodo = async (title) => {
        try {
            const data = {title: title}
            const req = await request('post', '/api/todos', data)
            if (req.data.message) {
                isLoading.value = false
                return alert(req.data.message)
            }
            todos.value.push(req.data.data)
        } catch (e) {
            await router.push('/')
        }
        isLoading.value = false
    }

    const handleLogout = () => {
        localStorage.removeItem('APP_DEMO_USER_TOKEN')
        router.push('/')
    }

    const addTodo = () => {
        if (todo.value === "") {
            return alert("Todo cannot be empty");
        }
        isLoading.value = true
        handleNewTodo(todo.value)
        todo.value = ""
    }

    const checked = async (val, index) => {
        try {
            const data = {has_completed: !val.has_completed}
            const req = await request('put', `/api/todos/${val.id}`, data)
            if (req.data.message) {
                isLoading.value = false
                return alert(req.data.message)
            }
            todos.value[index].has_completed = !val.has_completed
        } catch (e) {
            await router.push('/')
        }
        isLoading.value = false
    }

    const deleteTodo = async (val, index) => {
        if (window.confirm("Are you sure")) {
            try {
                const req = await request('delete', `/api/todos/${val.id}`)
                if (req.data.message) {
                    isLoading.value = false
                    todos.value.splice(index, 1)
                }
            } catch (e) {
                await router.push('/')
            }
            isLoading.value = false
        }
    }

For Laravel, we will create the following:

  • Controllers (AuthController, TodoController)
  • Models (Todo, User)
  • Routes (api)
  • Middleware (auth:sanctum).

Our routes are in api.php, which handles all the endpoints consumed by Vue.

Route::post('/auth/register', [AuthController::class, 'register']);
Route::post('/auth/login', [AuthController::class, 'login']);

Route::apiResource('todos', TodoController::class)->middleware('auth:sanctum');

Route::middleware('auth:sanctum')->get('/user', function (Request $request) {
    return $request->user();
});

The register logic in AuthController registers the user and creates a token.

public function register(Request $request): \Illuminate\Http\JsonResponse
{
    try {
        //Validated
        $validateUser = Validator::make($request->all(),
        [
            'name' => 'required',
            'email' => 'required|email|unique:users,email',
            'password' => 'required'
        ]);

        if($validateUser->fails()){
            return response()->json([
                'status' => false,
                'message' => 'validation error',
                'errors' => $validateUser->errors()
            ], 401);
        }

        $user = User::create([
            'name' => $request->name,
            'email' => $request->email,
            'password' => Hash::make($request->password)
        ], 201);

        return response()->json([
            'status' => true,
            'message' => 'User Created Successfully',
            'token' => $user->createToken("API_TOKEN")->plainTextToken
        ], 200);

    } catch (\Throwable $e) {
        return response()->json([
            'status' => false,
            'message' => $e->getMessage()
        ], 500);
    }
}

The login validates the request, checks if the user exists, and then creates a token:

public function login(Request $request): \Illuminate\Http\JsonResponse
{
    try {
        //Validated
        $validateUser = Validator::make($request->all(),
            [
                'email' => 'required',
                'password' => 'required'
            ]);

        if($validateUser->fails()){
            return response()->json([
                'status' => false,
                'message' => 'validation error',
                'errors' => $validateUser->errors()
            ], 401);
        }

        if(!Auth::attempt($request->only(['email', 'password']))){
            return response()->json([
                'status' => false,
                'message' => 'Email & Password does not exist.',
            ], 401);
        }

        $user = User::where('email', $request->email)->first();

        return response()->json([
            'status' => true,
            'message' => 'Logged In Successfully',
            'token' => $user->createToken("API_TOKEN")->plainTextToken
        ], 200);

    } catch (\Throwable $e) {
        return response()->json([
            'status' => false,
            'message' => $e->getMessage()
        ], 500);
    }
}

The POST endpoints for adding new to-dos are managed by the store method in the to-do controller — /api/todos.

public function store(Request $request): \Illuminate\Http\JsonResponse
{
    $data = Todo::where('user_id', $request->user()->id)->where('title', $request->title);
    if ($data->first()) {
        return response()->json(['status' => false, 'message' => 'Already exist']);
    }
    $req = $request->all();
    $req['user_id'] = $request->user()->id;
    $data = Todo::create($req);
    return response()->json(['status' => true, 'data' => $data], 201);
}

This manages the Todo update endpoint, which is called after a user completes a to-do and is located at /api/todos/id.

public function update(Request $request, $id): \Illuminate\Http\JsonResponse
{
    $validateUser = Validator::make($request->all(),
        [
            'has_completed' => 'required',
        ]);

    if ($validateUser->fails()) {
        return response()->json([
            'status' => false,
            'message' => 'validation error',
            'errors' => $validateUser->errors()
        ], 401);
    }

    $data = Todo::find($id);
    $data->has_completed = $request->has_completed;
    $data->update();
    return response()->json(['status' => true, 'data' => $data], 202);
}

When a user deletes a Todo, the endpoint /api/todos/id is called, and this takes care of it:

public function destroy(int $id): \Illuminate\Http\JsonResponse
{
    throw_if(!$id, 'todo Id is missing');
    Todo::findOrFail($id)->delete();
    return response()->json(['status' => true, 'message' => 'todo deleted']);
}

Well done, we’ve created a single-page app using Laravel and Vue! 🎉 Here’s the final result of our to-do app and a link to the source code:

Laravel Vue Single Page App Final Result

Conclusion

We were able to establish how much simpler it is to create a straightforward user authentication and to-do application using Vue and Laravel when compared to the traditional PHP/Vue combo — which can require a lot more setup work.

The combination of Vue with Laravel, in my view, makes it easy to develop single-page applications because there is no need to worry about routing, middleware, or handling CORS. Let me know about your experiences developing SPAs in the comments section below.

Thanks for reading! 

Original article source at https://blog.logrocket.com

#vue #laravel #php

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Build a Single-Page Application with Vue.js and Laravel
Luna  Mosciski

Luna Mosciski

1600583123

8 Popular Websites That Use The Vue.JS Framework

In this article, we are going to list out the most popular websites using Vue JS as their frontend framework.

Vue JS is one of those elite progressive JavaScript frameworks that has huge demand in the web development industry. Many popular websites are developed using Vue in their frontend development because of its imperative features.

This framework was created by Evan You and still it is maintained by his private team members. Vue is of course an open-source framework which is based on MVVM concept (Model-view view-Model) and used extensively in building sublime user-interfaces and also considered a prime choice for developing single-page heavy applications.

Released in February 2014, Vue JS has gained 64,828 stars on Github, making it very popular in recent times.

Evan used Angular JS on many operations while working for Google and integrated many features in Vue to cover the flaws of Angular.

“I figured, what if I could just extract the part that I really liked about Angular and build something really lightweight." - Evan You

#vuejs #vue #vue-with-laravel #vue-top-story #vue-3 #build-vue-frontend #vue-in-laravel #vue.js

Aria Barnes

Aria Barnes

1625232484

Why is Vue JS the most Preferred Choice for Responsive Web Application Development?

For more than two decades, JavaScript has facilitated businesses to develop responsive web applications for their customers. Used both client and server-side, JavaScript enables you to bring dynamics to pages through expanded functionality and real-time modifications.

Did you know!

According to a web development survey 2020, JavaScript is the most used language for the 8th year, with 67.7% of people choosing it. With this came up several javascript frameworks for frontend, backend development, or even testing.

And one such framework is Vue.Js. It is used to build simple projects and can also be advanced to create sophisticated apps using state-of-the-art tools. Beyond that, some other solid reasons give Vuejs a thumbs up for responsive web application development.

Want to know them? Then follow this blog until the end. Through this article, I will describe all the reasons and benefits of Vue js development. So, stay tuned.

Vue.Js - A Brief Introduction

Released in the year 2014 for public use, Vue.Js is an open-source JavaScript framework used to create UIs and single-page applications. It has over 77.4 million likes on Github for creating intuitive web interfaces.

The recent version is Vue.js 2.6, and is the second most preferred framework according to Stack Overflow Developer Survey 2019.

Every Vue.js development company is widely using the framework across the world for responsive web application development. It is centered around the view layer, provides a lot of functionality for the view layer, and builds single-page web applications.

Some most astonishing stats about Vue.Js:

• Vue was ranked #2 in the Front End JavaScript Framework rankings in the State of JS 2019 survey by developers.

• Approximately 427k to 693k sites are built with Vue js, according to Wappalyzer and BuiltWith statistics of June 2020.

• According to the State of JS 2019 survey, 40.5% of JavaScript developers are currently using Vue, while 34.5% have shown keen interest in using it in the future.

• In Stack Overflow's Developer Survey 2020, Vue was ranked the 3rd most popular front-end JavaScript framework.

Why is Vue.Js so popular?

• High-speed run-time performance
• Vue.Js uses a virtual DOM.
• The main focus is on the core library, while the collaborating libraries handle other features such as global state management and routing.
• Vue.JS provides responsive visual components.

Top 7 Reasons to Choose Vue JS for Web Application Development

Vue js development has certain benefits, which will encourage you to use it in your projects. For example, Vue.js is similar to Angular and React in many aspects, and it continues to enjoy increasing popularity compared to other frameworks.

The framework is only 20 kilobytes in size, making it easy for you to download files instantly. Vue.js easily beats other frameworks when it comes to loading times and usage.

Take a look at the compelling advantages of using Vue.Js for web app development.

#1 Simple Integration

Vue.Js is popular because it allows you to integrate Vue.js into other frameworks such as React, enabling you to customize the project as per your needs and requirements.

It helps you build apps with Vue.js from scratch and introduce Vue.js elements into their existing apps. Due to its ease of integration, Vue.js is becoming a popular choice for web development as it can be used with various existing web applications.

You can feel free to include Vue.js CDN and start using it. Most third-party Vue components and libraries are additionally accessible and supported with the Vue.js CDN.

You don't need to set up node and npm to start using Vue.js. This implies that it helps develop new web applications, just like modifying previous applications.

The diversity of components allows you to create different types of web applications and replace existing frameworks. In addition, you can also choose to hire Vue js developers to use the technology to experiment with many other JavaScript applications.

#2 Easy to Understand

One of the main reasons for the growing popularity of Vue.Js is that the framework is straightforward to understand for individuals. This means that you can easily add Vue.Js to your web projects.

Also, Vue.Js has a well-defined architecture for storing your data with life-cycle and custom methods. Vue.Js also provides additional features such as watchers, directives, and computed properties, making it extremely easy to build modern apps and web applications with ease.

Another significant advantage of using the Vue.Js framework is that it makes it easy to build small and large-scale web applications in the shortest amount of time.

#3 Well-defined Ecosystem

The VueJS ecosystem is vibrant and well-defined, allowing Vue.Js development company to switch users to VueJS over other frameworks for web app development.

Without spending hours, you can easily find solutions to your problems. Furthermore, VueJs lets you choose only the building blocks you need.

Although the main focus of Vue is the view layer, with the help of Vue Router, Vue Test Utils, Vuex, and Vue CLI, you can find solutions and recommendations for frequently occurring problems.

The problems fall into these categories, and hence it becomes easy for programmers to get started with coding right away and not waste time figuring out how to use these tools.

The Vue ecosystem is easy to customize and scales between a library and a framework. Compared to other frameworks, its development speed is excellent, and it can also integrate different projects. This is the reason why most website development companies also prefer the Vue.Js ecosystem over others.

#4 Flexibility

Another benefit of going with Vue.Js for web app development needs is flexibility. Vue.Js provides an excellent level of flexibility. And makes it easier for web app development companies to write their templates in HTML, JavaScript, or pure JavaScript using virtual nodes.

Another significant benefit of using Vue.Js is that it makes it easier for developers to work with tools like templating engines, CSS preprocessors, and type checking tools like TypeScript.

#5 Two-Way Communication

Vue.Js is an excellent option for you because it encourages two-way communication. This has become possible with the MVVM architecture to handle HTML blocks. In this way, Vue.Js is very similar to Angular.Js, making it easier to handle HTML blocks as well.

With Vue.Js, two-way data binding is straightforward. This means that any changes made by the developer to the UI are passed to the data, and the changes made to the data are reflected in the UI.

This is also one reason why Vue.Js is also known as reactive because it can react to changes made to the data. This sets it apart from other libraries such as React.Js, which are designed to support only one-way communication.

#6 Detailed Documentation

One essential thing is well-defined documentation that helps you understand the required mechanism and build your application with ease. It shows all the options offered by the framework and related best practice examples.

Vue has excellent docs, and its API references are one of the best in the industry. They are well written, clear, and accessible in dealing with everything you need to know to build a Vue application.

Besides, the documentation at Vue.js is constantly improved and updated. It also includes a simple introductory guide and an excellent overview of the API. Perhaps, this is one of the most detailed documentation available for this type of language.

#7 Large Community Support

Support for the platform is impressive. In 2018, support continued to impress as every question was answered diligently. Over 6,200 problems were solved with an average resolution time of just six hours.

To support the community, there are frequent release cycles of updated information. Furthermore, the community continues to grow and develop with backend support from developers.



Wrapping Up

VueJS is an incredible choice for responsive web app development. Since it is lightweight and user-friendly, it builds a fast and integrated web application. The capabilities and potential of VueJS for web app development are extensive.

While Vuejs is simple to get started with, using it to build scalable web apps requires professionalism. Hence, you can approach a top Vue js development company in India to develop high-performing web apps.

Equipped with all the above features, it doesn't matter whether you want to build a small concept app or a full-fledged web app; Vue.Js is the most performant you can rely on.

Original source

 

#vue js development company #vue js development company in india #vue js development company india #vue js development services #vue js development #vue js development companies

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

Paresh Sagar

1581940975

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