Tag: react.js

List of the array method with Javascript

.forEach()

const array = ["Alpha", "Beta", "Omega", "Neptune", "Danube", "Dniepr"];
array.forEach(el => console.log(el)) // basic
array.forEach((el, index, array) => console.log(el, index, array)) // all params
array.forEach(function(el, index, array) { // without arrow function
   return console.log(el, index, array)
})

.map()

const users = [
{name: "Alpha", level: 1}, 
{name: "Beta", level: 2}, 
{name: "Omega", level: 3}];
const names = users.map(user => user.name) // basic mapping in new array
console.log(names) // ["Alpha", "Beta", "Omega"]

.find() / .findIndex() / .indexOf()

const array = ["Alpha", "Beta", "Omega", "Neptune", "Danube", "Dniepr"];
console.log(array.find(el => el === "Alpha")) // ["Alpha"]
console.log(array.findIndex(el => el === "Alpha")) // 0
console.log(array.indexOf("Neptune")) // 3

The difference between indexOf and findIndex :
– findIndex : callback function so can do more things inside the callback function
– indexOf : using fast function with only one parameter

const users = [
{name: "Alpha", level: 1}, 
{name: "Beta", level: 2}, 
{name: "Omega", level: 3}];
console.log(users.find(el => el.name === "Alpha")) // [{name: "Alpha", level: 1}]

.some() / .every() / .includes()

const numbers = [12,14,23,27,11,9];
console.log(numbers.some(num => num === 40)) // false - do not have it
console.log(numbers.some(num => num === 12)) // true - yes have it
console.log(numbers.every(num => num < 20)) // false - not every item bellow 20
console.log(numbers.every(num => num < 40)) // true - yes every item bellow 40
console.log(numbers.includes(40)) // false - do not have it
console.log(numbers.includes(12)) // true - yes have it

.filter()

const numbers = [12,14,23,27,11,9];
const filteredNumbers = numbers.filter(num => num > 20) // [23, 27]

.sort()

Sort() works pretty good to order by ascending alphabetical order.
For numbers you will need to overload the condition in the callback function.

const numbers = [12,14,23,27,11,9];
const sortedNumbers = numbers.sort((a, b) => a - b) // [9, 11, 12, 14, 23, 27]
const array = ["Delta", "Neptune", "Alpha", "Danube", "Beta", "Dniepr"];
const sortedZone = array.sort() // ['Alpha', 'Beta', 'Danube', 'Delta', 'Dniepr', 'Neptune']

.reduce()

const numbers = [12,14,23,27,11,9];
const reducedNumbers = numbers.reduce((accumulator, currentValue) => accumulator + currentValue) // 96

AWS Amplify : Babel error building React.JS app

Is it possible you may have an error with babel on AWS Amplify, while deploying your React.JS app:

If you click on Frontend you should be able to see the logs :

2022-01-14T17:18:36.441Z [INFO]: $ react-scripts build
2022-01-14T17:18:37.352Z [INFO]: Creating an optimized production build...
2022-01-14T17:18:38.431Z [INFO]: Failed to compile.
2022-01-14T17:18:38.433Z [INFO]: ./src/index.js
                                 Error: [BABEL] /codebuild/output/src483533555/src/app/src/index.js: Cannot find module '@babel/helper-define-map'
                                 Require stack:
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/plugin-transform-classes/lib/transformClass.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/plugin-transform-classes/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/available-plugins.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/plugins-compat-data.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/normalize-options.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/node_modules/@babel/preset-env/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/create.js
                                 - /codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/config/files/plugins.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/config/files/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/@babel/core/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/node_modules/babel-loader/lib/index.js
                                 - /codebuild/output/src483533555/src/app/node_modules/loader-runner/lib/loadLoader.js
                                 - /codebuild/output/src483533555/src/app/node_modules/loader-runner/lib/LoaderRunner.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/NormalModule.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/NormalModuleFactory.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/Compiler.js
                                 - /codebuild/output/src483533555/src/app/node_modules/webpack/lib/webpack.js
                                 - /codebuild/output/src483533555/src/app/node_modules/react-scripts/scripts/build.js (While processing: "/codebuild/output/src483533555/src/app/node_modules/babel-preset-react-app/index.js")
2022-01-14T17:18:38.451Z [WARNING]: error Command failed with exit code 1.
2022-01-14T17:18:38.451Z [INFO]: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
2022-01-14T17:18:38.461Z [ERROR]: !!! Build failed
2022-01-14T17:18:38.461Z [ERROR]: !!! Non-Zero Exit Code detected
2022-01-14T17:18:38.461Z [INFO]: # Starting environment caching...
2022-01-14T17:18:38.461Z [INFO]: # Uploading environment cache artifact...
2022-01-14T17:18:38.534Z [INFO]: # Environment caching completed
Terminating logging...

In order to solve the @babel errors, you will need to install all the @babel packages:

NPM

npm install babel-core babel-loader babel-preset-env 
babel-preset-react babel-polyfill babel-runtime @babel/helpers 
@babel/helper-builder-react-jsx-experimental @babel/helper-builder-react-jsx 
@babel/helper-define-map @babel/helper-plugin-utils @babel/helper-regex

YARN

yarn add babel-core babel-loader babel-preset-env 
babel-preset-react babel-polyfill babel-runtime @babel/helpers 
@babel/helper-builder-react-jsx-experimental @babel/helper-builder-react-jsx 
@babel/helper-define-map @babel/helper-plugin-utils @babel/helper-regex

In order to run your React.JS project on Amplify, here is all the babel packages I installed to solve all problems:

  • babel-core
  • babel-loader
  • babel-preset-env
  • babel-preset-react
  • babel-polyfill
  • babel-runtime
  • @babel/helpers
  • @babel/helper-builder-react-jsx
  • @babel/helper-builder-react-jsx-experimental
  • @babel/helper-define-map
  • @babel/helper-plugin-utils
  • @babel/helper-regex

After, that, you should be able to see your React.JS app online with Amplify:

Color picker with React.JS

Example of a color picker made with React.JS

In order to have a color picker on our React.JS application, we can use the SketchPicker library

Full example

Color: <TextField variant="outlined" id="standard-basic" style={{padding: 5, width: '90%', background: color}} value={color?color:''} onChange={(e) => { setColor(e.target.value); }} />
<SketchPicker 
   color={ color?color:'#fff' }
   onChangeComplete={ (colorSelected) => {
         setColor(`${colorSelected.hex}${decimalToHex(colorSelected.rgb.a)}`);
      } 
   }
   presetColors={['#D0021B', '#F5A623', '#F8E71C', '#8B572A', '#7ED321', '#417505', '#BD10E0', '#9013FE', '#4A90E2', '#50E3C2', '#B8E986', '#000000', '#4A4A4A', '#9B9B9B', '#FFFFFF']}
/>

Alerting user with a small messaga bubble – Snackbar – React.JS

In your web app, you will have to notice the user when he is doing some actions in your user interface. We can do it with a small message bubble called Snackbar, here is what it looks like:

How we will do it

setSnackSeverity("error");
setSnackMessage("The last cell cannot be deleted.");
setOpenError(true);

In your code, we will use these 3 lines to:
– Set the severity “error”, there are 4 types of severity

– Set the error message that will be displayed “The last cell cannot be deleted.”
– Show the error message (during few seconds)

Full example

import Snackbar from '@material-ui/core/Snackbar';
import MuiAlert, { AlertProps } from '@material-ui/lab/Alert';
function Alert(props) {
  return <MuiAlert elevation={6} variant="filled" {...props} />;
}
...
const [snackSeverity, setSnackSeverity] = useState('error');
const [openError, setOpenError] = useState(false);
const [snackMessage,setSnackMessage] = useState('Error');
...
setSnackSeverity("error");
setSnackMessage("The last cell cannot be deleted.");
setOpenError(true);
...
<Snackbar
   anchorOrigin={{ vertical: 'bottom', horizontal: 'right' }}
   open={openError}
   onClose={(e)=>setOpenError(false)}
   autoHideDuration={3000} 
   >
     <Alert onClose={(e)=>setOpenError(false)} severity={snackSeverity}>
       {snackMessage}
     </Alert>
</Snackbar>

React.JS • Full list of all icons

Examples of listing the icons in React.JS / React Native

Listing all the icons

List of all the icons

Searching icons name

Searching an icon name

How to do it ?

Importing all the icons

Import the CSS your icons in /public/index.html

<link rel="stylesheet" href="http://cdn.materialdesignicons.com/5.4.55/css/materialdesignicons.min.css" />

Use it in your source code

Use your icons in the code source in /src/App.js like that:

<span> 
   <i class={`mdi mdi-${icon?icon:''}`} aria-hidden="true"></i>
</span>

Loop on all icons

If you want a list of icons then you can loop on the list of icons, let’s say you have put all your icons in a file called iconlist.js

export const icons = [
"ab-testing",
"abjad-arabic",
"abjad-hebrew",
"abugida-devanagari",
"abugida-thai",
"access-point",
"access-point-check",
"access-point-minus",
"access-point-network",
"access-point-network-off",
"access-point-off",
"access-point-plus",
"access-point-remove",
"account",
"account-alert",
"account-alert-outline",
"account-arrow-left",
"account-arrow-left-outline",
"account-arrow-right",
"account-arrow-right-outline",
"account-box",
"account-box-multiple",
"account-box-multiple-outline",
"account-box-outline",
"account-cancel",
"account-cancel-outline",
"account-cash",
"account-cash-outline",
"account-check",
...
];

Then you can import the icons in you App.js and use it:

import { icons } from './icons';
...
{ icons.map((icon, index) => (
   <div style={{fontWeight: 'bold'}}> <i class={`mdi mdi-${icon}`} aria-hidden="true"></i> {icon} </div>
))}

You can then add a filter if you want to check that the icons contain part of the string name :

const [searchIcon, setSearchIcon] = useState(null);
...
{ icons.filter(icon => icon.includes(searchIcon) ).map((icon, index) => (
    <div style={{fontWeight: 'bold'}}> <i class={`mdi mdi-${icon}`} aria-hidden="true"></i> {icon} </div>
  )
)}

ReactJS • Responsive UI interface

You are making a React application and you want to have a responsive user interface that works both on laptop and mobile phone ?

A solution can be to use Material UI with several layout components such :

  • Container
  • Grid
  • Hidden

The grid looks like this:

<Grid container spacing={3}>
        <Grid item xs={12}>
          <Paper className={classes.paper}>xs=12</Paper>
        </Grid>
        <Grid item xs={6}>
          <Paper className={classes.paper}>xs=6</Paper>
        </Grid>
        <Grid item xs={6}>
          <Paper className={classes.paper}>xs=6</Paper>
        </Grid>
        <Grid item xs={3}>
          <Paper className={classes.paper}>xs=3</Paper>
        </Grid>
        <Grid item xs={3}>
          <Paper className={classes.paper}>xs=3</Paper>
        </Grid>
        <Grid item xs={3}>
          <Paper className={classes.paper}>xs=3</Paper>
        </Grid>
        <Grid item xs={3}>
          <Paper className={classes.paper}>xs=3</Paper>
        </Grid>
      </Grid>

As you can see, the full width of the page is xs=12. It means the full width size is equal to 12.


You can see so that with 2 grid items of xs=6, it will be two components.
And so 4 will be 3 components on the line and 3 will be 4 components on the line.

You can use this grid items when you want to display block of contents on the page, if you know Bootstrap, it’s the same.

You can put any content inside your <Grid>, it can be a <div> for example.

Using XS, SM, MD, LG and XL

Grid SizeDeviceWeb browser width
XSMobile phone screens 0px ► 600x
SMMobile phone and tablets600px ► 960px
MDLaptop960px ► 1280px
LGLaptop1280px ► 1920px
XLDesktop1920px ► …

Using breakpoints

Using breakpoints allow you to have different grid size for different devices, which allows you to have a grid adapted for mobile phone for exemple:

You can se the size 6 for laptop (SM=6 and higher) and size is 12 for mobile phone (XS=12)

Using Hidden

You can use the <Hidden> element from Material UI to hide specific items for XS/SM/MD/LG/XL items.

<Hidden only="lg">
    <Paper className={classes.paper}>Hidden on lg</Paper>
</Hidden>