How to use Idle-timeout in React application

Idle timeout is one of the common features in every web application. In this post, we can see how we can implement this feature in the React application.

What is Idle Timeout

Idle timeout is the amount of time the user or client remains inactive on the web application. This is the time that the user doesn’t do anything on the app or away from the computer. It is typical for high-risk web apps to have 2–5 minutes of idle time and low-risk web apps to have 15–30 minutes of idle time before logging out the user.

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Why do we need it

Most of the cases we need an idle timeout in the web apps for security reasons and to avoid unnecessary calls to the API. The web app is vulnerable to security attacks. The longer it is idle, the more time for the attacker to inject some malicious code or hijack the session.

In another case, imagine a scenario where there are calls to be made to the backend API for every 30 sec or 1 min to retrieve the updated data. There is no need to make those calls if the user is away from the computer. We can avoid these unnecessary calls with the idle timeout feature.

Example Project

Here is an example project of implementing idle-timeout in React. You can clone this project and run it o your machine.

// clone the project
git clone https://github.com/bbachi/react-idle-timeout.git
// install dependencies and start the project
npm install
npm start

Here are the libraries used for this project.

react-bootstrap for the UI

react-idle-timer for the idle timeout

This is a simple project which has two screens: login screen and dashboard screen. When you log in with any username and password, dashboard displays with some user table. If you are idle for 5 seconds we are going to let the user know with a modal window and if the user is still idle after 5 seconds, the user will be logged out.

How To Find Out User is Idle

Actually we are using the library called ng-idle But, I want to show how we can detect the user is idle without any libraries. We have Keyboard events and mouse events from the DOM API which we can use to detect the users are idle or not. Basically, when there is no mouse or keyboard events fired, we can conclude that the user is idle.

// keyboard events link
https://developer.mozilla.org/en-US/docs/Web/Events#Keyboard_events

// mouse events
https://developer.mozilla.org/en-US/docs/Web/Events#Mouse_events

Here is some sample code with plain vanilla Javascript. There are only two events onmousemove and onkeypress used here but, we can use other events as well.

var inactivityTime = function () {
    var time;
    window.onload = resetTimer;
		
// DOM Events
    document.onmousemove = resetTimer;
    document.onkeypress = resetTimer;
		
    function resetTimer() {
        clearTimeout(time);
        time = setTimeout(logout, 3000)
    }
};

Implementation

Let’s see how we can implement the idle timeout feature in the React application with the react-idle-timer library. As a first step, we need to install react-idle-timer dependencies in the existing application.

npm i react-idle-timer --save

Once installed we have to import these modules in the Layout.js file.

import React from 'react'
import { Switch, Route } from 'react-router-dom'
import IdleTimer from 'react-idle-timer';
import { DashboardPage } from './dashboard/Dashboard'
import PropTypes from 'prop-types';
import 'bootstrap/dist/css/bootstrap.min.css';
import './App.css'

class Layout extends React.Component {

    constructor(props){
        super(props)
    }

    render(){
      const { match } = this.props
      return(
        <div className="">
            <Switch>
                <Route 
                    exact path={`${match.path}dashboard`}
                    render={(props) => <DashboardPage {...props} /> }/>
                />
            </Switch>
        </div>
        
      )
   }

 }

 Layout.propTypes = {
     match: PropTypes.any.isRequired,
     history: PropTypes.func.isRequired
 }

export default Layout

Since LayOut is the main component once logged in from the Login, we need to implement this logic in it. We are setting the Idle time 5 seconds which means we will get a warning message after 5 seconds of inactivity and timeout as 5 seconds which means it will be timed out within another 5 seconds.

I set both idle time and timeout time to 5 seconds for the demonstration purpose. Usually, these times are longer in the actual environments, typically it is around 15 mins.

import React from 'react'
import { Switch, Route } from 'react-router-dom'
import IdleTimer from 'react-idle-timer';
import { DashboardPage } from './dashboard/Dashboard'
import PropTypes from 'prop-types';
import 'bootstrap/dist/css/bootstrap.min.css';
import './App.css'

class Layout extends React.Component {

    constructor(props){
        super(props)

        this.state = {
            timeout:1000 * 5 * 1,
            showModal: false,
            userLoggedIn: false,
            isTimedOut: false
        }

        this.idleTimer = null
        this.onAction = this._onAction.bind(this)
        this.onActive = this._onActive.bind(this)
        this.onIdle = this._onIdle.bind(this)
    }

    _onAction(e) {
      console.log('user did something', e)
      this.setState({isTimedOut: false})
    }
   
    _onActive(e) {
      console.log('user is active', e)
      this.setState({isTimedOut: false})
    }
   
    _onIdle(e) {
      console.log('user is idle', e)
      const isTimedOut = this.state.isTimedOut
      if (isTimedOut) {
          this.props.history.push('/')
      } else {
        this.setState({showModal: true})
        this.idleTimer.reset();
        this.setState({isTimedOut: true})
      }
      
    }

    render(){
      const { match } = this.props
      return(
        <>
          <IdleTimer
            ref={ref => { this.idleTimer = ref }}
            element={document}
            onActive={this.onActive}
            onIdle={this.onIdle}
            onAction={this.onAction}
            debounce={250}
            timeout={this.state.timeout} />

            <div className="">
                <Switch>
                    <Route 
                        exact path={`${match.path}dashboard`}
                        render={(props) => <DashboardPage {...props} /> }/>
                    />
                </Switch>
            </div>
        </>
      )
   }

 }

 Layout.propTypes = {
     match: PropTypes.any.isRequired,
     history: PropTypes.func.isRequired
 }

export default Layout

I want to show a modal window whenever the user is idle and give some options for the user to logout or stay as shown in the figure.

For this, we are using a react-bootstrap modal component. We need to create a separate component and import that component in the Layout.js as shown below.

This is a stateless component which takes props and returns modal window based on the properties provided to this component. Notice that we are importing required components Modal and Button from react-bootstrap.

import React from 'react';
import Modal from 'react-bootstrap/Modal';
import Button from 'react-bootstrap/Button';

export const IdleTimeOutModal = ({showModal, handleClose, handleLogout, remainingTime}) => {

    return (
        <Modal show={showModal} onHide={handleClose}>
            <Modal.Header closeButton>
            <Modal.Title>You Have Been Idle!</Modal.Title>
            </Modal.Header>
            <Modal.Body>You Will Get Timed Out. You want to stay?</Modal.Body>
            <Modal.Footer>
            <Button variant="danger" onClick={handleLogout}>
                Logout
            </Button>
            <Button variant="primary" onClick={handleClose}>
                Stay
            </Button>
            </Modal.Footer>
        </Modal>
    )
}

Once created, we need to import this file in the Layout.js and pass the required props.

// Idletimout Modal part of Layout.js component

import { IdleTimeOutModal } from './modal/IdleModal'

class Layout extends React.Component {

    constructor(props){
        super(props)

        this.state = {
            timeout:1000 * 5 * 1,
            showModal: false,
            userLoggedIn: false,
            isTimedOut: false
        }
        this.handleClose = this.handleClose.bind(this)
        this.handleLogout = this.handleLogout.bind(this)
    }

    handleClose() {
      this.setState({showModal: false})
    }

    handleLogout() {
      this.setState({showModal: false})
      this.props.history.push('/')
    }

    render(){
      const { match } = this.props
      return(
        <>
            <div className="">
                <Switch>
                    <Route 
                        exact path={`${match.path}dashboard`}
                        render={(props) => <DashboardPage {...props} /> }/>
                    />
                </Switch>
                
                <IdleTimeOutModal 
                    showModal={this.state.showModal} 
                    handleClose={this.handleClose}
                    handleLogout={this.handleLogout}
                />
            </div>
        </>
      )
   }

 }

 Layout.propTypes = {
     match: PropTypes.any.isRequired,
     history: PropTypes.func.isRequired
 }

export default Layout

Along with this, we don’t want the idle timeout feature on the login screen. For this, I created Layout.js which has all the routes besides login. Here is the App component which loads the Layout component for the route /dashboard and the Layout component loads the actual DashboardPage component.

import React from 'react'
import { BrowserRouter, Switch, Route } from 'react-router-dom'
import { Header } from './header/Header'
import { Footer }from './footer/Footer'
import Layout from './Layout'
import PropTypes from 'prop-types';
import 'bootstrap/dist/css/bootstrap.min.css';
import './App.css'
import { LoginPage } from './login/Login'

class App extends React.Component {

    constructor(props){
        super(props)
    }

    render(){

      return(
        <div className="App">
          <Header />
          <BrowserRouter>
            <Switch>
              <Route exact path="/" component={LoginPage} />
              <Route path='/' render={(props) => <Layout {...props} /> } />
            </Switch>
          </BrowserRouter>
          <Footer />
        </div>
      )
   }

 }

 App.propTypes = {
     match: PropTypes.any.isRequired,
     history: PropTypes.func.isRequired
 }

export default App

// routung part of Layout Page

<div className="">
  <Switch>
      <Route 
          exact path={`${match.path}dashboard`}
          render={(props) => <DashboardPage {...props} /> }/>
      />
  </Switch>
</div>

Here is the complete Layout.js file. If you notice the function _onIdle() at line 40. We are logging out the user if he is idle even after showing the modal window. We can accomplish this in a number of ways but I used isTimedOut the property in the state. When the user is idle for the first time, I am showing the modal window and setting this flag as true in the state and reset the timer. If the user is still idle, I am logging the user out based on the flag isTimedOut

If the user responds to that modal window, we are using handleLogout and handleClose functions to take the appropriate action at lines 53 and 57 respectively.

import React from 'react'
import { Switch, Route } from 'react-router-dom'
import IdleTimer from 'react-idle-timer';
import { DashboardPage } from './dashboard/Dashboard'
import { IdleTimeOutModal } from './modal/IdleModal'
import PropTypes from 'prop-types';
import 'bootstrap/dist/css/bootstrap.min.css';
import './App.css'

class Layout extends React.Component {

    constructor(props){
        super(props)

        this.state = {
            timeout:1000 * 5 * 1,
            showModal: false,
            userLoggedIn: false,
            isTimedOut: false
        }

        this.idleTimer = null
        this.onAction = this._onAction.bind(this)
        this.onActive = this._onActive.bind(this)
        this.onIdle = this._onIdle.bind(this)
        this.handleClose = this.handleClose.bind(this)
        this.handleLogout = this.handleLogout.bind(this)
    }

    _onAction(e) {
      console.log('user did something', e)
      this.setState({isTimedOut: false})
    }
   
    _onActive(e) {
      console.log('user is active', e)
      this.setState({isTimedOut: false})
    }
   
    _onIdle(e) {
      console.log('user is idle', e)
      const isTimedOut = this.state.isTimedOut
      if (isTimedOut) {
          this.props.history.push('/')
      } else {
        this.setState({showModal: true})
        this.idleTimer.reset();
        this.setState({isTimedOut: true})
      }
      
    }

    handleClose() {
      this.setState({showModal: false})
    }

    handleLogout() {
      this.setState({showModal: false})
      this.props.history.push('/')
    }

    render(){
      const { match } = this.props
      return(
        <>
          <IdleTimer
            ref={ref => { this.idleTimer = ref }}
            element={document}
            onActive={this.onActive}
            onIdle={this.onIdle}
            onAction={this.onAction}
            debounce={250}
            timeout={this.state.timeout} />

            <div className="">
                <Switch>
                    <Route 
                        exact path={`${match.path}dashboard`}
                        render={(props) => <DashboardPage {...props} /> }/>
                    />
                </Switch>
                
                <IdleTimeOutModal 
                    showModal={this.state.showModal} 
                    handleClose={this.handleClose}
                    handleLogout={this.handleLogout}
                />
            </div>
        </>
      )
   }

 }

 Layout.propTypes = {
     match: PropTypes.any.isRequired,
     history: PropTypes.func.isRequired
 }

export default Layout

Summary

• Idle timeout is one of the common features in every web application yet a very important one.
• We can avoid malicious attacks and unnecessary backend API calls with this feature.
• We can actually detect the idle user with the help of DOM events: keyboard events and mouse events.
• For React applications, we can use the react-idle-timer library.
• It’s always good to let the user know with the modal popup that he/she has been idle before logging them out.

You may also like: Angular vs React vs Vue: Which one will be popular 

Conclusion

Idle timeout feature is the most common yet powerful feature to avoid malicious attacks and unnecessary backend calls.

Thank for visiting and reading this article! I’m highly appreciate your actions! Please share if you liked it!

#reactjs #javascript #web-development

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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.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

Pdf2gerb: Perl Script Converts PDF Files to Gerber format

pdf2gerb

Perl script converts PDF files to Gerber format

Pdf2Gerb generates Gerber 274X photoplotting and Excellon drill files from PDFs of a PCB. Up to three PDFs are used: the top copper layer, the bottom copper layer (for 2-sided PCBs), and an optional silk screen layer. The PDFs can be created directly from any PDF drawing software, or a PDF print driver can be used to capture the Print output if the drawing software does not directly support output to PDF.

The general workflow is as follows:

1. Design the PCB using your favorite CAD or drawing software.
2. Print the top and bottom copper and top silk screen layers to a PDF file.
3. Run Pdf2Gerb on the PDFs to create Gerber and Excellon files.
4. Use a Gerber viewer to double-check the output against the original PCB design.
5. Make adjustments as needed.
6. Submit the files to a PCB manufacturer.

Please note that Pdf2Gerb does NOT perform DRC (Design Rule Checks), as these will vary according to individual PCB manufacturer conventions and capabilities. Also note that Pdf2Gerb is not perfect, so the output files must always be checked before submitting them. As of version 1.6, Pdf2Gerb supports most PCB elements, such as round and square pads, round holes, traces, SMD pads, ground planes, no-fill areas, and panelization. However, because it interprets the graphical output of a Print function, there are limitations in what it can recognize (or there may be bugs).

See docs/Pdf2Gerb.pdf for install/setup, config, usage, and other info.

---

pdf2gerb_cfg.pm

#Pdf2Gerb config settings:
#Put this file in same folder/directory as pdf2gerb.pl itself (global settings),
#or copy to another folder/directory with PDFs if you want PCB-specific settings.
#There is only one user of this file, so we don't need a custom package or namespace.
#NOTE: all constants defined in here will be added to main namespace.
#package pdf2gerb_cfg;

use strict; #trap undef vars (easier debug)
use warnings; #other useful info (easier debug)


##############################################################################################
#configurable settings:
#change values here instead of in main pfg2gerb.pl file

use constant WANT_COLORS => ($^O !~ m/Win/); #ANSI colors no worky on Windows? this must be set < first DebugPrint() call

#just a little warning; set realistic expectations:
#DebugPrint("${\(CYAN)}Pdf2Gerb.pl ${\(VERSION)}, $^O O/S\n${\(YELLOW)}${\(BOLD)}${\(ITALIC)}This is EXPERIMENTAL software.  \nGerber files MAY CONTAIN ERRORS.  Please CHECK them before fabrication!${\(RESET)}", 0); #if WANT_DEBUG

use constant METRIC => FALSE; #set to TRUE for metric units (only affect final numbers in output files, not internal arithmetic)
use constant APERTURE_LIMIT => 0; #34; #max #apertures to use; generate warnings if too many apertures are used (0 to not check)
use constant DRILL_FMT => '2.4'; #'2.3'; #'2.4' is the default for PCB fab; change to '2.3' for CNC

use constant WANT_DEBUG => 0; #10; #level of debug wanted; higher == more, lower == less, 0 == none
use constant GERBER_DEBUG => 0; #level of debug to include in Gerber file; DON'T USE FOR FABRICATION
use constant WANT_STREAMS => FALSE; #TRUE; #save decompressed streams to files (for debug)
use constant WANT_ALLINPUT => FALSE; #TRUE; #save entire input stream (for debug ONLY)

#DebugPrint(sprintf("${\(CYAN)}DEBUG: stdout %d, gerber %d, want streams? %d, all input? %d, O/S: $^O, Perl: $]${\(RESET)}\n", WANT_DEBUG, GERBER_DEBUG, WANT_STREAMS, WANT_ALLINPUT), 1);
#DebugPrint(sprintf("max int = %d, min int = %d\n", MAXINT, MININT), 1); 

#define standard trace and pad sizes to reduce scaling or PDF rendering errors:
#This avoids weird aperture settings and replaces them with more standardized values.
#(I'm not sure how photoplotters handle strange sizes).
#Fewer choices here gives more accurate mapping in the final Gerber files.
#units are in inches
use constant TOOL_SIZES => #add more as desired
(
#round or square pads (> 0) and drills (< 0):
    .010, -.001,  #tiny pads for SMD; dummy drill size (too small for practical use, but needed so StandardTool will use this entry)
    .031, -.014,  #used for vias
    .041, -.020,  #smallest non-filled plated hole
    .051, -.025,
    .056, -.029,  #useful for IC pins
    .070, -.033,
    .075, -.040,  #heavier leads
#    .090, -.043,  #NOTE: 600 dpi is not high enough resolution to reliably distinguish between .043" and .046", so choose 1 of the 2 here
    .100, -.046,
    .115, -.052,
    .130, -.061,
    .140, -.067,
    .150, -.079,
    .175, -.088,
    .190, -.093,
    .200, -.100,
    .220, -.110,
    .160, -.125,  #useful for mounting holes
#some additional pad sizes without holes (repeat a previous hole size if you just want the pad size):
    .090, -.040,  #want a .090 pad option, but use dummy hole size
    .065, -.040, #.065 x .065 rect pad
    .035, -.040, #.035 x .065 rect pad
#traces:
    .001,  #too thin for real traces; use only for board outlines
    .006,  #minimum real trace width; mainly used for text
    .008,  #mainly used for mid-sized text, not traces
    .010,  #minimum recommended trace width for low-current signals
    .012,
    .015,  #moderate low-voltage current
    .020,  #heavier trace for power, ground (even if a lighter one is adequate)
    .025,
    .030,  #heavy-current traces; be careful with these ones!
    .040,
    .050,
    .060,
    .080,
    .100,
    .120,
);
#Areas larger than the values below will be filled with parallel lines:
#This cuts down on the number of aperture sizes used.
#Set to 0 to always use an aperture or drill, regardless of size.
use constant { MAX_APERTURE => max((TOOL_SIZES)) + .004, MAX_DRILL => -min((TOOL_SIZES)) + .004 }; #max aperture and drill sizes (plus a little tolerance)
#DebugPrint(sprintf("using %d standard tool sizes: %s, max aper %.3f, max drill %.3f\n", scalar((TOOL_SIZES)), join(", ", (TOOL_SIZES)), MAX_APERTURE, MAX_DRILL), 1);

#NOTE: Compare the PDF to the original CAD file to check the accuracy of the PDF rendering and parsing!
#for example, the CAD software I used generated the following circles for holes:
#CAD hole size:   parsed PDF diameter:      error:
#  .014                .016                +.002
#  .020                .02267              +.00267
#  .025                .026                +.001
#  .029                .03167              +.00267
#  .033                .036                +.003
#  .040                .04267              +.00267
#This was usually ~ .002" - .003" too big compared to the hole as displayed in the CAD software.
#To compensate for PDF rendering errors (either during CAD Print function or PDF parsing logic), adjust the values below as needed.
#units are pixels; for example, a value of 2.4 at 600 dpi = .0004 inch, 2 at 600 dpi = .0033"
use constant
{
    HOLE_ADJUST => -0.004 * 600, #-2.6, #holes seemed to be slightly oversized (by .002" - .004"), so shrink them a little
    RNDPAD_ADJUST => -0.003 * 600, #-2, #-2.4, #round pads seemed to be slightly oversized, so shrink them a little
    SQRPAD_ADJUST => +0.001 * 600, #+.5, #square pads are sometimes too small by .00067, so bump them up a little
    RECTPAD_ADJUST => 0, #(pixels) rectangular pads seem to be okay? (not tested much)
    TRACE_ADJUST => 0, #(pixels) traces seemed to be okay?
    REDUCE_TOLERANCE => .001, #(inches) allow this much variation when reducing circles and rects
};

#Also, my CAD's Print function or the PDF print driver I used was a little off for circles, so define some additional adjustment values here:
#Values are added to X/Y coordinates; units are pixels; for example, a value of 1 at 600 dpi would be ~= .002 inch
use constant
{
    CIRCLE_ADJUST_MINX => 0,
    CIRCLE_ADJUST_MINY => -0.001 * 600, #-1, #circles were a little too high, so nudge them a little lower
    CIRCLE_ADJUST_MAXX => +0.001 * 600, #+1, #circles were a little too far to the left, so nudge them a little to the right
    CIRCLE_ADJUST_MAXY => 0,
    SUBST_CIRCLE_CLIPRECT => FALSE, #generate circle and substitute for clip rects (to compensate for the way some CAD software draws circles)
    WANT_CLIPRECT => TRUE, #FALSE, #AI doesn't need clip rect at all? should be on normally?
    RECT_COMPLETION => FALSE, #TRUE, #fill in 4th side of rect when 3 sides found
};

#allow .012 clearance around pads for solder mask:
#This value effectively adjusts pad sizes in the TOOL_SIZES list above (only for solder mask layers).
use constant SOLDER_MARGIN => +.012; #units are inches

#line join/cap styles:
use constant
{
    CAP_NONE => 0, #butt (none); line is exact length
    CAP_ROUND => 1, #round cap/join; line overhangs by a semi-circle at either end
    CAP_SQUARE => 2, #square cap/join; line overhangs by a half square on either end
    CAP_OVERRIDE => FALSE, #cap style overrides drawing logic
};
    
#number of elements in each shape type:
use constant
{
    RECT_SHAPELEN => 6, #x0, y0, x1, y1, count, "rect" (start, end corners)
    LINE_SHAPELEN => 6, #x0, y0, x1, y1, count, "line" (line seg)
    CURVE_SHAPELEN => 10, #xstart, ystart, x0, y0, x1, y1, xend, yend, count, "curve" (bezier 2 points)
    CIRCLE_SHAPELEN => 5, #x, y, 5, count, "circle" (center + radius)
};
#const my %SHAPELEN =
#Readonly my %SHAPELEN =>
our %SHAPELEN =
(
    rect => RECT_SHAPELEN,
    line => LINE_SHAPELEN,
    curve => CURVE_SHAPELEN,
    circle => CIRCLE_SHAPELEN,
);

#panelization:
#This will repeat the entire body the number of times indicated along the X or Y axes (files grow accordingly).
#Display elements that overhang PCB boundary can be squashed or left as-is (typically text or other silk screen markings).
#Set "overhangs" TRUE to allow overhangs, FALSE to truncate them.
#xpad and ypad allow margins to be added around outer edge of panelized PCB.
use constant PANELIZE => {'x' => 1, 'y' => 1, 'xpad' => 0, 'ypad' => 0, 'overhangs' => TRUE}; #number of times to repeat in X and Y directions

# Set this to 1 if you need TurboCAD support.
#$turboCAD = FALSE; #is this still needed as an option?

#CIRCAD pad generation uses an appropriate aperture, then moves it (stroke) "a little" - we use this to find pads and distinguish them from PCB holes. 
use constant PAD_STROKE => 0.3; #0.0005 * 600; #units are pixels
#convert very short traces to pads or holes:
use constant TRACE_MINLEN => .001; #units are inches
#use constant ALWAYS_XY => TRUE; #FALSE; #force XY even if X or Y doesn't change; NOTE: needs to be TRUE for all pads to show in FlatCAM and ViewPlot
use constant REMOVE_POLARITY => FALSE; #TRUE; #set to remove subtractive (negative) polarity; NOTE: must be FALSE for ground planes

#PDF uses "points", each point = 1/72 inch
#combined with a PDF scale factor of .12, this gives 600 dpi resolution (1/72 * .12 = 600 dpi)
use constant INCHES_PER_POINT => 1/72; #0.0138888889; #multiply point-size by this to get inches

# The precision used when computing a bezier curve. Higher numbers are more precise but slower (and generate larger files).
#$bezierPrecision = 100;
use constant BEZIER_PRECISION => 36; #100; #use const; reduced for faster rendering (mainly used for silk screen and thermal pads)

# Ground planes and silk screen or larger copper rectangles or circles are filled line-by-line using this resolution.
use constant FILL_WIDTH => .01; #fill at most 0.01 inch at a time

# The max number of characters to read into memory
use constant MAX_BYTES => 10 * M; #bumped up to 10 MB, use const

use constant DUP_DRILL1 => TRUE; #FALSE; #kludge: ViewPlot doesn't load drill files that are too small so duplicate first tool

my $runtime = time(); #Time::HiRes::gettimeofday(); #measure my execution time

print STDERR "Loaded config settings from '${\(__FILE__)}'.\n";
1; #last value must be truthful to indicate successful load


#############################################################################################
#junk/experiment:

#use Package::Constants;
#use Exporter qw(import); #https://perldoc.perl.org/Exporter.html

#my $caller = "pdf2gerb::";

#sub cfg
#{
#    my $proto = shift;
#    my $class = ref($proto) || $proto;
#    my $settings =
#    {
#        $WANT_DEBUG => 990, #10; #level of debug wanted; higher == more, lower == less, 0 == none
#    };
#    bless($settings, $class);
#    return $settings;
#}

#use constant HELLO => "hi there2"; #"main::HELLO" => "hi there";
#use constant GOODBYE => 14; #"main::GOODBYE" => 12;

#print STDERR "read cfg file\n";

#our @EXPORT_OK = Package::Constants->list(__PACKAGE__); #https://www.perlmonks.org/?node_id=1072691; NOTE: "_OK" skips short/common names

#print STDERR scalar(@EXPORT_OK) . " consts exported:\n";
#foreach(@EXPORT_OK) { print STDERR "$_\n"; }
#my $val = main::thing("xyz");
#print STDERR "caller gave me $val\n";
#foreach my $arg (@ARGV) { print STDERR "arg $arg\n"; }

---

Download Details:

Author: swannman
Source Code: https://github.com/swannman/pdf2gerb

License: GPL-3.0 license

#perl 

What are hooks in React JS? - INFO AT ONE

In this article, you will learn what are hooks in React JS? and when to use react hooks? React JS is developed by Facebook in the year 2013. There are many students and the new developers who have confusion between react and hooks in react. Well, it is not different, react is a programming language and hooks is a function which is used in react programming language.
Read More:- https://infoatone.com/what-are-hooks-in-react-js/

#react #hooks in react #react hooks example #react js projects for beginners #what are hooks in react js? #when to use react hooks

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

#hire-react-js-developer #hire-react-native-developer #react #react-native #react-js #hire-react-js-programmer

React Starter Kit: Build Web Apps with React, Relay and GraphQL.

React Starter Kit — "isomorphic" web app boilerplate   

React Starter Kit is an opinionated boilerplate for web development built on top of Node.js, Express, GraphQL and React, containing modern web development tools such as Webpack, Babel and Browsersync. Helping you to stay productive following the best practices. A solid starting point for both professionals and newcomers to the industry.

See getting started guide, demo, docs, roadmap  |  Join #react-starter-kit chat room on Gitter  |  Visit our sponsors:

 

Hiring

Getting Started

• Follow the getting started guide to download and run the project (Node.js >= 8.16.2)
• Check the code recipes used in this boilerplate, or share yours

Customization

The master branch of React Starter Kit doesn't include a Flux implementation or any other advanced integrations. Nevertheless, we have some integrations available to you in feature branches that you can use either as a reference or merge into your project:

• feature/redux (PR) — isomorphic Redux by Pavel Lang (see how to integrate Redux) (based on master)
• feature/apollo (PR) — isomorphic Apollo Client by Pavel Lang (see Tracking PR #1147) (based on feature/redux)
• feature/react-intl (PR) — isomorphic Redux and React Intl by Pavel Lang (see how to integrate React Intl) (based on feature/apollo)
• feature/apollo-pure (PR) — Apollo devtools and TypeScript integration by piglovesyou (based on master)

You can see status of most reasonable merge combination as PRs labeled as TRACKING

If you think that any of these features should be on master, or vice versa, some features should removed from the master branch, please let us know. We love your feedback!

Comparison

	React Starter Kit	React Static Boilerplate	ASP.NET Core Starter Kit
App type	Isomorphic (universal)	Single-page application	Single-page application
Frontend
Language	JavaScript (ES2015+, JSX)	JavaScript (ES2015+, JSX)	JavaScript (ES2015+, JSX)
Libraries	React, History, Universal Router	React, History, Redux	React, History, Redux
Routes	Imperative (functional)	Declarative	Declarative, cross-stack
Backend
Language	JavaScript (ES2015+, JSX)	n/a	C#, F#
Libraries	Node.js, Express, Sequelize, GraphQL	n/a	ASP.NET Core, EF Core, ASP.NET Identity
SSR	Yes	n/a	n/a
Data API	GraphQL	n/a	Web API

Backers

♥ React Starter Kit? Help us keep it alive by donating funds to cover project expenses via OpenCollective or Bountysource!

 

How to Contribute

Anyone and everyone is welcome to contribute to this project. The best way to start is by checking our open issues, submit a new issue or feature request, participate in discussions, upvote or downvote the issues you like or dislike, send pull requests.

Learn More

• Getting Started with React.js
• Getting Started with GraphQL and Relay
• React.js Questions on StackOverflow
• React.js Discussion Board
• Flux Architecture for Building User Interfaces
• Enzyme — JavaScript Testing utilities for React
• Flow — A static type checker for JavaScript
• The Future of React
• Learn ES6, ES6 Features

Related Projects

• GraphQL Starter Kit — Boilerplate for building data APIs with Node.js, JavaScript (via Babel) and GraphQL
• Membership Database — SQL schema boilerplate for user accounts, profiles, roles, and auth claims
• Babel Starter Kit — Boilerplate for authoring JavaScript/React.js libraries

Support

• #react-starter-kit on Stack Overflow — Questions and answers
• #react-starter-kit on Gitter — Watch announcements, share ideas and feedback
• GitHub issues, or Scrum board — File issues, send feature requests
• appear.in/react — Open hours! Exchange ideas and experiences (React, GraphQL, startups and pet projects)
• @koistya on Codementor, or Skype — Private consulting

License

Copyright © 2014-present Kriasoft, LLC. This source code is licensed under the MIT license found in the LICENSE.txt file. The documentation to the project is licensed under the CC BY-SA 4.0 license.

---

Author: kriasoft
Source Code: https://github.com/kriasoft/react-starter-kit
License: MIT License

#graphql #react