Suppose there are two dice and a button to roll the dices. As we click the button both dices shake and generate a new number that shows on the upper face of the dices(in doted form as a standard dice). The numbers show on the upper face generates randomly each time we roll the dice.
There are two components Die and RollDice. The Die component is responsible to show one individual Dice. It is a stateless component. It uses the font-awesome library to show the standard dots on the upper face of the dice. RollDice component contains all the logic to generates random numbers to show on the upper face of the dice, roll each dice upon click on the roll button. There are two states involve in the RollDice component named ‘die1’ and ‘die2’. Each one has initialized with the value one i.e. each die shows one(one dot) when the application first starts.
Now, we set the click event handler to the roll dice button and when anyone clicks on the button we change the state of both die1 and die2 to some random number using setState from one to six (we use a number as a word since font-awesome library deals with word number to show the exact number of dots). We also make sure when the dice is rolling user can’t click on the button again. For this purpose we use a state ‘rolling’ initially set to false and when the dice are rolling set rolling to true and start a timer of one second. After one second again set rolling state to false’. Disable the button when a rolling state is set to true.
This is a rough overview of the application. Let’s implement it to understand it better.
Example:
-
index.js:
Javascript
import React from
'react'
import ReactDOM from
'react-dom'
import App from
'./App'
ReactDOM.render(<App />, document.querySelector(
'#root'
))
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App.js: App component renders a single RollDice component only
Javascript
import React from
'react'
;
import RollDice from
'./RollDice'
function
App() {
return
(
<div>
<RollDice />
</div>
);
}
export
default
App;
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RollDice.js : It contains all the behind the logic. The setting event handler, updating all the states according to the user’s interaction render Die component. This file has to be created by you.
Javascript
import React,{ Component } from
'react'
import
'./RollDice.css'
import Die from
'./Die'
class RollDice extends Component{
// Face numbers passes as default props
static defaultProps = {
sides : [
'one'
,
'two'
,
'three'
,
'four'
,
'five'
,
'six'
]
}
constructor(props){
super
(props)
// States
this
.state = {
die1 :
'one'
,
die2 :
'one'
,
rolling:
false
}
this
.roll =
this
.roll.bind(
this
)
}
roll(){
const {sides} =
this
.props
this
.setState({
// Changing state upon click
die1 : sides[Math.floor(Math.random() * sides.length)],
die2 : sides[Math.floor(Math.random() * sides.length)],
rolling:
true
})
// Start timer of one sec when rolling start
setTimeout(() => {
// Set rolling to false again when time over
this
.setState({rolling:
false
})
},1000)
}
render(){
const handleBtn =
this
.state.rolling ?
'RollDice-rolling'
:
''
const {die1, die2, rolling} =
this
.state
return
(
<div className=
'RollDice'
>
<div className=
'RollDice-container'
>
<Die face={die1} rolling={rolling}/>
<Die face={die2} rolling={rolling}/>
</div>
<button className={handleBtn}
disabled={
this
.state.rolling}
onClick={
this
.roll}>
{
this
.state.rolling ?
'Rolling'
:
'Roll Dice!'
}
</button>
</div>
)
}
}
export
default
RollDice
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Die.js: Responsible to show single-die component only with correct doted number face as communicated by the parent RollDice component. This file has to be created by you.
Javascript
import React, {Component} from
'react'
import
'./Die.css'
class Die extends Component{
render(){
const {face, rolling} =
this
.props
// Using font awesome icon to show
// the exactnumber of dots
return
<i className={`Die fas fa-dice-${face}
${rolling &&
'Die-shaking'
}`}/>
}
}
export
default
Die
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RollDice.css : Styling RollDice component contents
CSS
.RollDice{
display
: flex;
flex-flow: column
nowrap
;
min-height
:
100
vh;
}
/* Shows each dice in one row */
.RollDice-container{
display
: flex;
justify-
content
:
center
;
align-
content
:
center
;
}
/* Stylling rolldice button */
.RollDice button{
width
:
15em
;
padding
:
1.5em
;
border
:
0px
;
border-radius:
10px
;
color
:
white
;
background-color
:
black
;
margin-top
:
3em
;
align-self:
center
;
}
/* Setting hover effect on button */
.RollDice button:hover{
cursor
:
pointer
;
}
.RollDice-rolling{
border
:
0px
;
border-radius:
10px
;
background-color
:darkslateblue
!important
;
opacity:
0.7
}
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Die.css: Styling each die component and setting animation effect to it.
CSS
/* Styling each Die */
.Die{
font-size
:
10em
;
padding
:
0.25em
;
color
:slateblue;
}
/* Applying Animation */
.Die-shaking{
animation-name:wobble;
animation-duration:
1
s;
}
/* Setting Animation effect to the
dice using css keyframe */
@keyframes wobble {
from {
transform: translate
3
d(
0
,
0
,
0
);
}
15%
{
transform: translate
3
d(
-25%
,
0
,
0
)
rotate
3
d(
0
,
0
,
1
,
-5
deg);
}
30%
{
transform: translate
3
d(
20%
,
0
,
0
)
rotate
3
d(
0
,
0
,
1
,
3
deg);
}
45%
{
transform: translate
3
d(
-15%
,
0
,
0
)
rotate
3
d(
0
,
0
,
1
,
-3
deg);
}
60%
{
transform: translate
3
d(
10%
,
0
,
0
)
rotate
3
d(
0
,
0
,
1
,
2
deg);
}
75%
{
transform: translate
3
d(
-5%
,
0
,
0
)
rotate
3
d(
0
,
0
,
1
,
-1
deg);
}
to {
transform: translate
3
d(
0
,
0
,
0
);
}
}
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Output :