JavaScript Moderne - Comment faire usage de la boucle While en JS

Javascript moderne (ES6 - ES11) #13 Comment faire usage de la boucle While en JS [Tuto fr]

Télécharger VS Code : https://code.visualstudio.com/

Le code source : https://github.com/drcmind/Javascript-Moderne


les amis dans cette nouvelle série de vidéos on va apprendre ensemble le langage de programmation Javascript depuis sa version ECMA2015 jusqu’à ECMA2020 (ES6 - ES11) et delà on se focalisera beaucoup sur la notion de :

  1. Let et Const
  2. Arrow function
  3. Object literal
  4. Template String
  5. Destructuring assignment
  6. Default parameter
  7. Rest et Spread operators
  8. Class, Modules, Promises, iterators
  9. Await/Async
  10. Map et Set

#javascript #programming #web-development #developer

What is GEEK

Buddha Community

JavaScript Moderne - Comment faire usage de la boucle While en JS

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

JavaScript Moderne - Comment faire usage de la boucle While en JS

Javascript moderne (ES6 - ES11) #13 Comment faire usage de la boucle While en JS [Tuto fr]

Télécharger VS Code : https://code.visualstudio.com/

Le code source : https://github.com/drcmind/Javascript-Moderne


les amis dans cette nouvelle série de vidéos on va apprendre ensemble le langage de programmation Javascript depuis sa version ECMA2015 jusqu’à ECMA2020 (ES6 - ES11) et delà on se focalisera beaucoup sur la notion de :

  1. Let et Const
  2. Arrow function
  3. Object literal
  4. Template String
  5. Destructuring assignment
  6. Default parameter
  7. Rest et Spread operators
  8. Class, Modules, Promises, iterators
  9. Await/Async
  10. Map et Set

#javascript #programming #web-development #developer

JavaScript Moderne - Comment faire usage de la boucle For en JS

Javascript moderne (ES6 - ES11) #12 Comment faire usage de la boucle For en JS [Tuto fr]

Télécharger VS Code : https://code.visualstudio.com/

Le code source : https://github.com/drcmind/Javascript-Moderne


les amis dans cette nouvelle série de vidéos on va apprendre ensemble le langage de programmation Javascript depuis sa version ECMA2015 jusqu’à ECMA2020 (ES6 - ES11) et delà on se focalisera beaucoup sur la notion de :

  1. Let et Const
  2. Arrow function
  3. Object literal
  4. Template String
  5. Destructuring assignment
  6. Default parameter
  7. Rest et Spread operators
  8. Class, Modules, Promises, iterators
  9. Await/Async
  10. Map et Set

#javascript #programming #web-development #developer

Leonard  Paucek

Leonard Paucek

1656280800

Jump to Local IDE Code Directly From Browser React Component

React Dev Inspector

Jump to local IDE code directly from browser React component by just a simple click

This package allows users to jump to local IDE code directly from browser React component by just a simple click, which is similar to Chrome inspector but more advanced.

View Demo View Github

Preview

press hotkey (ctrl⌃ + shift⇧ + commmand⌘ + c), then click the HTML element you wish to inspect.

screen record gif (8M size):

Jump to local IDE code directly from browser React component by just a simple click

Installation

npm i -D react-dev-inspector

Usage

Users need to add React component and apply webpack config before connecting your React project with 'react-dev-inspector'.

Note: You should NOT use this package, and React component, webpack config in production mode


 

1. Add Inspector React Component

import React from 'react'
import { Inspector, InspectParams } from 'react-dev-inspector'

const InspectorWrapper = process.env.NODE_ENV === 'development'
  ? Inspector
  : React.Fragment

export const Layout = () => {
  // ...

  return (
     {}}
      onClickElement={(params: InspectParams) => {}}
    >
     
       ...
     
    
  )
}


 

2. Set up Inspector Config

You should add:

  • an inspector babel plugin, to inject source code location info
    • react-dev-inspector/plugins/babel
  • an server api middleware, to open local IDE
    • import { launchEditorMiddleware } from 'react-dev-inspector/plugins/webpack'

to your current project development config.

Such as add babel plugin into your .babelrc or webpack babel-loader config,
add api middleware into your webpack-dev-server config or other server setup.


 

There are some example ways to set up, please pick the one fit your project best.

In common cases, if you're using webpack, you can see #raw-webpack-config,

If your project happen to use vite / nextjs / create-react-app and so on, you can also try out our integrated plugins / examples with

raw webpack config

Example:

// .babelrc.js
module.exports = {
  plugins: [
    /**
     * react-dev-inspector plugin, options docs see:
     * https://github.com/zthxxx/react-dev-inspector#inspector-babel-plugin-options
     */
    'react-dev-inspector/plugins/babel',
  ],
}
// webpack.config.ts
import type { Configuration } from 'webpack'
import { launchEditorMiddleware } from 'react-dev-inspector/plugins/webpack'

const config: Configuration = {
  /**
   * [server side] webpack dev server side middleware for launch IDE app
   */
  devServer: {
    before: (app) => {
      app.use(launchEditorMiddleware)
    },
  },
}


 

usage with Vite2

example project see: https://github.com/zthxxx/react-dev-inspector/tree/master/examples/vite2

example vite.config.ts:

import { defineConfig } from 'vite'
import { inspectorServer } from 'react-dev-inspector/plugins/vite'

export default defineConfig({
  plugins: [
    inspectorServer(),
  ],
})


 

usage with Next.js

use Next.js Custom Server + Customizing Babel Config

example project see: https://github.com/zthxxx/react-dev-inspector/tree/master/examples/nextjs

in server.js, example:

...

const {
  queryParserMiddleware,
  launchEditorMiddleware,
} = require('react-dev-inspector/plugins/webpack')

app.prepare().then(() => {
  createServer((req, res) => {
    /**
     * middlewares, from top to bottom
     */
    const middlewares = [
      /**
       * react-dev-inspector configuration two middlewares for nextjs
       */
      queryParserMiddleware,
      launchEditorMiddleware,

      /** Next.js default app handle */
        (req, res) => handle(req, res),
    ]

    const middlewarePipeline = middlewares.reduceRight(
      (next, middleware) => (
        () => { middleware(req, res, next) }
      ),
      () => {},
    )

    middlewarePipeline()

  }).listen(PORT, (err) => {
    if (err) throw err
    console.debug(`> Ready on http://localhost:${PORT}`)
  })
})

in package.json, example:

  "scripts": {
-    "dev": "next dev",
+    "dev": "node server.js",
    "build": "next build"
  }

in .babelrc.js, example:

module.exports = {
  plugins: [
    /**
     * react-dev-inspector plugin, options docs see:
     * https://github.com/zthxxx/react-dev-inspector#inspector-babel-plugin-options
     */
    'react-dev-inspector/plugins/babel',
  ],
}


 

usage with create-react-app

cra + react-app-rewired + customize-cra example config-overrides.js:

example project see: https://github.com/zthxxx/react-dev-inspector/tree/master/examples/cra

const { ReactInspectorPlugin } = require('react-dev-inspector/plugins/webpack')
const {
  addBabelPlugin,
  addWebpackPlugin,
} = require('customize-cra')

module.exports = override(
  addBabelPlugin([
    'react-dev-inspector/plugins/babel',
    // plugin options docs see:
    // https://github.com/zthxxx/react-dev-inspector#inspector-babel-plugin-options
    {
      excludes: [
        /xxxx-want-to-ignore/,
      ],
    },
  ]),
  addWebpackPlugin(
    new ReactInspectorPlugin(),
  ),
)


 

usage with Umi3

example project see: https://github.com/zthxxx/react-dev-inspector/tree/master/examples/umi3

Example .umirc.dev.ts:

// https://umijs.org/config/
import { defineConfig } from 'umi'

export default defineConfig({
  plugins: [
    'react-dev-inspector/plugins/umi/react-inspector',
  ],
  inspectorConfig: {
    // babel plugin options docs see:
    // https://github.com/zthxxx/react-dev-inspector#inspector-babel-plugin-options
    excludes: [],
  },
})


 

usage with Umi2

Example .umirc.dev.js:

import { launchEditorMiddleware } from 'react-dev-inspector/plugins/webpack'

export default {
  // ...
  extraBabelPlugins: [
    // plugin options docs see:
    // https://github.com/zthxxx/react-dev-inspector#inspector-babel-plugin-options
    'react-dev-inspector/plugins/babel',
  ],

  /**
   * And you need to set `false` to `dll` in `umi-plugin-react`,
   * becase these is a umi2 bug that `dll` cannot work with `devServer.before`
   *
   * https://github.com/umijs/umi/issues/2599
   * https://github.com/umijs/umi/issues/2161
   */
  chainWebpack(config, { webpack }) {
    const originBefore = config.toConfig().devServer

    config.devServer.before((app, server, compiler) => {
      
      app.use(launchEditorMiddleware)
      
      originBefore?.before?.(app, server, compiler)
    })

    return config  
  },
}

usage with Ice.js

Example build.json:

// https://ice.work/docs/guide/basic/build
{
  "plugins": [
    "react-dev-inspector/plugins/ice",
  ]
}


 

Examples Project Code


 

Configuration

Component Props

checkout TS definition under react-dev-inspector/es/Inspector.d.ts.

PropertyDescriptionTypeDefault
keysinspector hotkeys

supported keys see: https://github.com/jaywcjlove/hotkeys#supported-keys
string[]['control', 'shift', 'command', 'c']
disableLaunchEditordisable editor launching

(launch by default in dev Mode, but not in production mode)
booleanfalse
onHoverElementtriggered when mouse hover in inspector mode(params: InspectParams) => void-
onClickElementtriggered when mouse hover in inspector mode(params: InspectParams) => void-
// import type { InspectParams } from 'react-dev-inspector'

interface InspectParams {
  /** hover / click event target dom element */
  element: HTMLElement,
  /** nearest named react component fiber for dom element */
  fiber?: React.Fiber,
  /** source file line / column / path info for react component */
  codeInfo?: {
    lineNumber: string,
    columnNumber: string,
    /**
    * code source file relative path to dev-server cwd(current working directory)
    * need use with `react-dev-inspector/plugins/babel`
    */
    relativePath?: string,
    /**
    * code source file absolute path
    * just need use with `@babel/plugin-transform-react-jsx-source` which auto set by most framework
    */
    absolutePath?: string,
  },
  /** react component name for dom element */
  name?: string,
}


 

Inspector Babel Plugin Options

interface InspectorPluginOptions {
  /** override process.cwd() */
  cwd?: string,
  /** patterns to exclude matched files */
  excludes?: (string | RegExp)[],
}


 

Inspector Loader Props

// import type { ParserPlugin, ParserOptions } from '@babel/parser'
// import type { InspectorConfig } from 'react-dev-inspector/plugins/webpack'

interface InspectorConfig {
  /** patterns to exclude matched files */
  excludes?: (string | RegExp)[],
  /**
   * add extra plugins for babel parser
   * default is ['typescript', 'jsx', 'decorators-legacy', 'classProperties']
   */
  babelPlugins?: ParserPlugin[],
  /** extra babel parser options */
  babelOptions?: ParserOptions,
}


 

IDE / Editor config

This package uses react-dev-utils to launch your local IDE application, but, which one will be open?

In fact, it uses an environment variable named REACT_EDITOR to specify an IDE application, but if you do not set this variable, it will try to open a common IDE that you have open or installed once it is certified.

For example, if you want it always open VSCode when inspection clicked, set export REACT_EDITOR=code in your shell.


 

VSCode

install VSCode command line tools, see the official docs
install-vscode-cli

set env to shell, like .bashrc or .zshrc

export REACT_EDITOR=code


 

WebStorm

  • just set env with an absolute path to shell, like .bashrc or .zshrc (only MacOS)
export REACT_EDITOR='/Applications/WebStorm.app/Contents/MacOS/webstorm'

OR

install WebStorm command line tools
Jump to local IDE code directly from browser React component by just a simple click

then set env to shell, like .bashrc or .zshrc

export REACT_EDITOR=webstorm


 

Vim

Yes! you can also use vim if you want, just set env to shell

export REACT_EDITOR=vim


 

How It Works

Stage 1 - Compile Time

  • [babel plugin] inject source file path/line/column to JSX data attributes props

Stage 2 - Web React Runtime

[React component] Inspector Component in react, for listen hotkeys, and request api to dev-server for open IDE.

Specific, when you click a component DOM, the Inspector will try to obtain its source file info (path/line/column), then request launch-editor api (in stage 3) with absolute file path.

Stage 3 - Dev-server Side

[middleware] setup launchEditorMiddleware in webpack dev-server (or other dev-server), to open file in IDE according to the request params.

Only need in development mode,and you want to open IDE when click a component element.

Not need in prod mode, or you just want inspect dom without open IDE (set disableLaunchEditor={true} to Inspector component props)

Analysis of Theory


Author: zthxxx
Source code: https://github.com/zthxxx/react-dev-inspector
License: MIT license

#react-native #react 

Ajay Kapoor

1626321063

JS Development Company India | JavaScript Development Services

PixelCrayons: Our JavaScript web development service offers you a feature-packed & dynamic web application that effectively caters to your business challenges and provide you the best RoI. Our JavaScript web development company works on all major frameworks & libraries like Angular, React, Nodejs, Vue.js, to name a few.

With 15+ years of domain expertise, we have successfully delivered 13800+ projects and have successfully garnered 6800+ happy customers with 97%+ client retention rate.

Looking for professional JavaScript web app development services? We provide custom JavaScript development services applying latest version frameworks and libraries to propel businesses to the next level. Our well-defined and manageable JS development processes are balanced between cost, time and quality along with clear communication.

Our JavaScript development companies offers you strict NDA, 100% money back guarantee and agile/DevOps approach.

#javascript development company #javascript development services #javascript web development #javascript development #javascript web development services #javascript web development company