Identifies accessibility issues in your React.js Elements

React A11y

Identifies accessibility issues in your React.js elements

DEPRECATION NOTICE

This library is being deprecated in favor of react-axe.
Deque Systems are one of the top authorities on web accessibility. Their auditing tools based on their axe-core engine are unrivaled and have become the gold standard for auditing web accessibility issues. Now that they have developed a runtime React DOM auditing tool, that does what react-a11y attempts to do but better, it seems counterproductive to continue to maintain react-a11y. Let’s pool our resources and energies into the best product and I believe any accessibility tool backed by the experts at Deque Systems is bound to be one we can trust and depend on. Please go check out and install react-axe today!

Installation

Run:

npm install react-a11y

Usage

In your main application file, require the module and call it, you’ll start getting warnings in the console as your app renders. Note that by default all rules are turned off so you need to turn them on first (by setting them to "warn" or "error").

import React    from 'react';
import ReactDOM from 'react-dom';

if (process.env.NODE_ENV === 'development') {
  const a11y = require('react-a11y').default;
  a11y(React, ReactDOM, {
    rules: {
      'img-uses-alt': 'warn',
      'img-redundant-alt': [ 'warn', [ 'image', 'photo', 'foto', 'bild' ]]
    // ...
    }
  });
}

You probably don’t want to call it if you’re in production, since it patches the React rendering functions and this might make this slower.

Migrating to v1.1.0

A number of the rule names have changed and the previous rule names have been deprecated. These deprecated rules will be removed in v2.0.0. The following is the mapping of old to new rules:

Old Rule	New Rule
avoid-positive-tabindex	tabindex-no-positive
button-role-space	click-events-have-key-events
label-uses-for	label-has-for
mouse-events-map-to-key-events	mouse-events-have-key-events
no-unsupported-elements-use-aria	aria-unsupported-elements
onclick-uses-tabindex	interactive-supports-focus
redundant-alt	img-redundant-alt
use-onblur-not-onchange	no-onchange
valid-aria-role	aria-role

Options

These are the supported configuration options, annotated using flow type annotations

a11y(React : React, ReactDOM : ReactDOM, opts : object? );

React is the React object you want to shim to allow the accessibility tests.

ReactDOM is the ReactDOM object you’re using to render the React components. This is only used on the client side, so you can safely omit it when using react-a11y in node.

`options`:

plugins : [string] An array of strings corresponding to names of plugins to be used. Eg. if the array contains 'aria-wai' it would include the rules in a (yet to be written) react-a11y-plugin-aria-wai module. You are responsible for installing this module.
rules : object The configuration options for each of the rules. This uses the same format as eslint does:
```
const rules = {
  'img-uses-alt': 'off',
  'redundant-alt': [
    'warn',
    // other options to pass to the rule:
    [
      'foto'
    ]
  ]
};
```
Refer to the rule docs to see what options are defined for each rule.
reporter : object => undefined Use this to modify how the warnings are displayed. The reporter is a function that accepts an object with the following keys:
- msg : string - the error message
- tagName : string - the tagName of the violating element (eg. 'img')
- severity : string - the severity as configured by the user in the corresponding rule configuration (one of 'off', 'warn', or 'error')
- props : object - the props as passed to the element
- displayName : string? - the displayName of the owner, if any
- DOMNode : object? - the violating DOMNode as rendered to the browser DOM, this is only available on when react-a11y is running in the browser.
- url : string? - The url to a webpage explaining why this rule is important
The default reporter displays all the information it can, but listens to the deprecated options includeSrcNode, warningPrefix and throwErro and throwError.
filterFn : (string, string, string) => boolean You can filter failures by passing a function to the filterFn option. The filter function will receive three arguments: the name of the Component instance or ReactElement, the id of the violating element, and the failure message.

Note: If it is a ReactElement, the name will be the node type (eg. div)
```
// only show errors on CommentList
const commentListFailures = function (name, id, msg) {
  return name === "CommentList";
};

a11y(React, ReactDOM, { filterFn: commentListFailures });
```

Cleaning Up In Tests

Use the restoreAll() method to clean up mutations made to React. Useful if you are using react-a11y in your test suite:

beforeEach(() => a11y(React));
afterEach(() => a11y.restoreAll());

Writing plugins

The rules in this version of react-a11y are pluggable! You can write your own plugin to add more rules. Have a look at writing plugins in the docs to get started!

Download Details:

Author: reactjs

GitHub: https://github.com/reactjs/react-a11y

#reactjs #javascript #react-js

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Buddha Community

Identifies accessibility issues in your React.js Elements

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

Performance: It delivers optimal performance.
Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
UI design: React Native enables you to design simple and responsive UI for your mobile app.
3rd party plugins: This framework supports 3rd party plugins.
Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
Near-native user experience: React Native provides several native components, and these are platform agnostic.
The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

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JavaScript Daily

1632537859

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:

c64core: retrocompute aesthetics twitter bot
gallery.cljs: script to download walpapers from windowsonearth.org.
nbb-action-example: example of a Github action 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

Mathew Rini

1615544450

How to Select and Hire the Best React JS and React Native Developers?

Since March 2020 reached 556 million monthly downloads have increased, It shows that React JS has been steadily growing. React.js also provides a desirable amount of pliancy and efficiency for developing innovative solutions with interactive user interfaces. It’s no surprise that an increasing number of businesses are adopting this technology. How do you select and recruit React.js developers who will propel your project forward? How much does a React developer make? We’ll bring you here all the details you need.

What is React.js?

Facebook built and maintains React.js, an open-source JavaScript library for designing development tools. React.js is used to create single-page applications (SPAs) that can be used in conjunction with React Native to develop native cross-platform apps.

React vs React Native

React Native is a platform that uses a collection of mobile-specific components provided by the React kit, while React.js is a JavaScript-based library.
React.js and React Native have similar syntax and workflows, but their implementation is quite different.
React Native is designed to create native mobile apps that are distinct from those created in Objective-C or Java. React, on the other hand, can be used to develop web apps, hybrid and mobile & desktop applications.
React Native, in essence, takes the same conceptual UI cornerstones as standard iOS and Android apps and assembles them using React.js syntax to create a rich mobile experience.

What is the Average React Developer Salary?

In the United States, the average React developer salary is $94,205 a year, or $30-$48 per hour, This is one of the highest among JavaScript developers. The starting salary for junior React.js developers is $60,510 per year, rising to $112,480 for senior roles.

* React.js Developer Salary by Country

United States- $120,000
Canada - $110,000
United Kingdom - $71,820
The Netherlands $49,095
Spain - $35,423.00
France - $44,284
Ukraine - $28,990
India - $9,843
Sweden - $55,173
Singapore - $43,801

In context of software developer wage rates, the United States continues to lead. In high-tech cities like San Francisco and New York, average React developer salaries will hit $98K and $114per year, overall.

However, the need for React.js and React Native developer is outpacing local labour markets. As a result, many businesses have difficulty locating and recruiting them locally.

It’s no surprise that for US and European companies looking for professional and budget engineers, offshore regions like India are becoming especially interesting. This area has a large number of app development companies, a good rate with quality, and a good pool of React.js front-end developers.

As per Linkedin, the country’s IT industry employs over a million React specialists. Furthermore, for the same or less money than hiring a React.js programmer locally, you may recruit someone with much expertise and a broader technical stack.

How to Hire React.js Developers?

Conduct thorough candidate research, including portfolios and areas of expertise.
Before you sit down with your interviewing panel, do some homework.
Examine the final outcome and hire the ideal candidate.

Why is React.js Popular?

React is a very strong framework. React.js makes use of a powerful synchronization method known as Virtual DOM, which compares the current page architecture to the expected page architecture and updates the appropriate components as long as the user input.

React is scalable. it utilises a single language, For server-client side, and mobile platform.

React is steady.React.js is completely adaptable, which means it seldom, if ever, updates the user interface. This enables legacy projects to be updated to the most new edition of React.js without having to change the codebase or make a few small changes.

React is adaptable. It can be conveniently paired with various state administrators (e.g., Redux, Flux, Alt or Reflux) and can be used to implement a number of architectural patterns.

Is there a market for React.js programmers?
The need for React.js developers is rising at an unparalleled rate. React.js is currently used by over one million websites around the world. React is used by Fortune 400+ businesses and popular companies such as Facebook, Twitter, Glassdoor and Cloudflare.

Final thoughts:

As you’ve seen, locating and Hire React js Developer and Hire React Native developer is a difficult challenge. You will have less challenges selecting the correct fit for your projects if you identify growing offshore locations (e.g. India) and take into consideration the details above.

If you want to make this process easier, You can visit our website for more, or else to write a email, we’ll help you to finding top rated React.js and React Native developers easier and with strives to create this operation

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Spring Framework

1642110180

Spring: A Static Web Site Generator Written By GitHub Issues

Spring

Spring is a blog engine written by GitHub Issues, or is a simple, static web site generator. No more server and database, you can setup it in free hosting with GitHub Pages as a repository, then post the blogs in the repository Issues.

You can add some labels in your repository Issues as the blog category, and create Issues for writing blog content through Markdown.

Spring has responsive templates, looking good on mobile, tablet, and desktop.Gracefully degrading in older browsers. Compatible with Internet Explorer 10+ and all modern browsers.

Get up and running in seconds.

中文介绍

Quick start guide

For the impatient, here's how to get a Spring blog site up and running.

First of all

Fork the Spring repository as yours.
Goto your repository settings page to rename Repository Name.
Hosted directly on GitHub Pages from your project repository, you can take it as User or organization site or Project site(create a gh-pages branch).
Also, you can set up a custom domain with Pages.

Secondly

Open the index.html file to edit the config variables with yours below.

$.extend(spring.config, {
  // my blog title
  title: 'Spring',
  // my blog description
  desc: "A blog engine written by github issues [Fork me on GitHub](https://github.com/zhaoda/spring)",
  // my github username
  owner: 'zhaoda',
  // creator's username
  creator: 'zhaoda',
  // the repository name on github for writting issues
  repo: 'spring',
  // custom page
  pages: [
  ]
})

Put your domain into the CNAME file if you have.
Commit your change and push it.

And then

Goto your repository settings page to turn on the Issues feature.
Browser this repository's issues page, like this https://github.com/your-username/your-repo-name/issues?state=open.
Click the New Issue button to just write some content as a new one blog.

Finally

Browser this repository's GitHub Pages url, like this http://your-username.github.io/your-repo-name, you will see your Spring blog, have a test.
And you're done!

Custom development

Installation

You will need a web server installed on your system, for example, Nginx, Apache etc.
Configure your spring project to your local web server directory.
Run and browser it, like http://localhost/spring/dev.html .
dev.html is used to develop, index.html is used to runtime.

Folder Structure

spring/
├── css/
|    ├── boot.less  #import other less files
|    ├── github.less  #github highlight style
|    ├── home.less  #home page style
|    ├── issuelist.less #issue list widget style
|    ├── issues.less #issues page style
|    ├── labels.less #labels page style
|    ├── main.less #commo style
|    ├── markdown.less #markdown format style
|    ├── menu.less #menu panel style
|    ├── normalize.less #normalize style
|    ├── pull2refresh.less #pull2refresh widget style
|    └── side.html  #side panel style
├── dist/
|    ├── main.min.css  #css for runtime
|    └── main.min.js  #js for runtime
├── img/  #some icon, startup images
├── js/
|    ├── lib/  #some js librarys need to use
|    ├── boot.js  #boot
|    ├── home.js  #home page
|    ├── issuelist.js #issue list widget
|    ├── issues.js #issues page
|    ├── labels.js #labels page
|    ├── menu.js #menu panel
|    ├── pull2refresh.less #pull2refresh widget
|    └── side.html  #side panel
├── css/
|    ├── boot.less  #import other less files
|    ├── github.less  #github highlight style
|    ├── home.less  #home page style
|    ├── issuelist.less #issue list widget style
|    ├── issues.less #issues page style
|    ├── labels.less #labels page style
|    ├── main.less #commo style
|    ├── markdown.less #markdown format style
|    ├── menu.less #menu panel style
|    ├── normalize.less #normalize style
|    ├── pull2refresh.less #pull2refresh widget style
|    └── side.html  #side panel style
├── dev.html #used to develop
├── favicon.ico #website icon
├── Gruntfile.js #Grunt task config
├── index.html #used to runtime
└── package.json  #nodejs install config

Customization

Browser http://localhost/spring/dev.html, enter the development mode.
Changes you want to modify the source code, like css, js etc.
Refresh dev.html view change.

Building

You will need Node.js installed on your system.
Installation package.

bash

$ npm install

*   Run grunt task.

    ```bash
$ grunt

Browser http://localhost/spring/index.html, enter the runtime mode.
If there is no problem, commit and push the code.
Don't forget to merge master branch into gh-pages branch if you have.
And you're done! Good luck!

Report a bug

Check if the bug is already fixed in the master branch since the last release.
Check existing issues.
Open a new one, including exact browser & platform information.

Who used

If you are using, please tell me.

Download Details:
Author: zhaoda
Source Code: https://github.com/zhaoda/spring
License: MIT License

#spring #spring-framework #spring-boot #java

Identifies accessibility issues in your React.js Elements

React A11y

DEPRECATION NOTICE

Installation

Usage

Migrating to v1.1.0

Options

options:

Cleaning Up In Tests

Writing plugins

Download Details:

What is GEEK

Buddha Community

How native is React Native? | React Native vs Native App Development

A brief introduction to React Native

Why React Native is fundamentally different from earlier hybrid frameworks

Top React JS Development Company | React JS Development Services

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Status

Goals and features

Requirements

How does this tool work?

Usage

Macros

Startup time

Dependencies

NPM dependencies

Classpath

Current file

Reagent

Promesa

Js-interop

Examples

API

Migrating to shadow-cljs

Build

How to Select and Hire the Best React JS and React Native Developers?

What is React.js?

React vs React Native

What is the Average React Developer Salary?

* React.js Developer Salary by Country

How to Hire React.js Developers?

Why is React.js Popular?

Final thoughts:

Spring: A Static Web Site Generator Written By GitHub Issues

Spring

Quick start guide

First of all

Secondly

And then

Finally

Custom development

Installation

Folder Structure

Customization

Building

Report a bug

Who used

`options`: