Develop Reference

React suggestions Input setting state

im prety new to React and im trying to use an autocomplete input. Im having problems getting the value from it and clearing the input values after submitting. Any help would be greatly appretiated.
import React, { Component, Fragment } from "react";
import PropTypes from "prop-types";
import "../AutoComplete/styles.css"
class Autocomplete extends Component {
static propTypes = {
suggestions: PropTypes.instanceOf(Array)
};
static defaultProps = {
suggestions: [],
};
constructor(props) {
super(props);
this.state = {
// The active selection's index
activeSuggestion: 0,
// The suggestions that match the user's input
filteredSuggestions: [],
// Whether or not the suggestion list is shown
showSuggestions: false,
// What the user has entered
userInput: this.props.value ? this.props.value : "",
};
}
//Order by 'code'
generateSortFn(prop, reverse) {
return function (a, b) {
if (a[prop] < b[prop]) return reverse ? -1 : 1;
if (a[prop] > b[prop]) return reverse ? 1 : -1;
return 0;
};
}
onChange = e => {
const { suggestions } = this.props;
const userInput = e.currentTarget.value;
// Filter our suggestions that don't contain the user's input
const filteredSuggestions = suggestions.sort(this.generateSortFn('code', true)).filter(
(suggestion, i) => {
let aux = suggestion.descrp+"- "+suggestion.code
return aux.toLowerCase().indexOf(userInput.toLowerCase()) > -1
}
);
this.setState({
activeSuggestion: 0,
filteredSuggestions,
showSuggestions: true,
userInput: e.currentTarget.value
});
};
onClick = e => {
this.setState({
activeSuggestion: 0,
filteredSuggestions: [],
showSuggestions: false,
userInput: e.currentTarget.innerText
});
};
onKeyDown = e => {
const { activeSuggestion, filteredSuggestions } = this.state;
// User pressed the enter key
if (e.keyCode === 13) {
this.setState({
activeSuggestion: 0,
showSuggestions: false,
userInput: filteredSuggestions[activeSuggestion].code+" - "+filteredSuggestions[activeSuggestion].descrp
});
}
// User pressed the up arrow
else if (e.keyCode === 38) {
if (activeSuggestion === 0) {
return;
}
this.setState({ activeSuggestion: activeSuggestion - 1 });
}
// User pressed the down arrow
else if (e.keyCode === 40) {
if (activeSuggestion - 1 === filteredSuggestions.length) {
return;
}
this.setState({ activeSuggestion: activeSuggestion + 1 });
}
};
render() {
const {
onChange,
onClick,
onKeyDown,
state: {
activeSuggestion,
filteredSuggestions,
showSuggestions,
userInput
}
} = this;
let suggestionsListComponent;
if (showSuggestions && userInput) {
if (filteredSuggestions.length) {
suggestionsListComponent = (
<ul className="suggestions">
{filteredSuggestions.map((suggestion, index) => {
let className="";
// Flag the active suggestion with a class
if (index === activeSuggestion) {
className = "suggestion-active";
}
return (
<li className={className} key={suggestion.code} onClick={onClick}>
{suggestion.code+" - "+suggestion.descrp}
</li>
);
})}
</ul>
);
} else {
suggestionsListComponent = (
<div className="no-suggestions">
<p>Sin sugerencias</p>
</div>
);
}
}
and the return (this is where i think im wrong)
return (
<Fragment>
<label htmlFor="autocomplete-input" className="autocompleteLabel">{this.props.label}</label>
<div className="centerInput">
<input
className="autocomplete-input"
type="text"
onChange={onChange}
onKeyDown={onKeyDown}
defaultValue={this.props.initState}
value= {/* this.props.value ? this.props.value : */ userInput}
placeholder={this.props.placeholder}
selection={this.setState(this.props.selection)}
/>
{suggestionsListComponent}
</div>
</Fragment>
);
}
}
export default Autocomplete;
What I want is to use this component in different pages, so im passing the "selection" prop and setting the state there.
The input is working correctly (searches, gets the value and shows/hide the helper perfectly). The problem is i cant reset this inputs clearing them, and i suspect the error is in here.
I get the following warning (even with it somewhat functioning)
Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state.
This is the Component usage with useState:
<Autocomplete label='Out cost Center:' placeholder='Set the out cost center' suggestions={dataCostCenterHelper} selection={(text) => setOutCostCenter(text.userInput)} value={outCostCenter} />
and last this is how im tryin to clear the state that is set in "selection":
const clearData = async () => {
setOutCostCenter('-');
// other inputs with the same component
setOutVendor('-');
setOutRefNumber('-');
}
This gets called inside the function that handles the button submitting the form.
Thanks in advance!

Looking at the code you posted this line might be the problem:
selection={this.setState(this.props.selection)}
You are updating state directly inside the render method, this is not recommended.
Try using a selection prop or state field and update the prop inside a componenteDidMount life cycle
selection={this.state.selection}

How to check value is empty, or null in JavaScript?

I have a problem when I wanna get data from state, in console.log appears 2 values. I want remove the empty value, but I've run out of ways. How to remove an empty value?
class DetailOrderTracking extends Component {
constructor(props) {
super(props)
this.state = {
data: []
}
}
componentDidMount = async () => {
const { query } = this.props.router;
var getOrderTrackings = await OrderTrackingRepository.getOrderTracking(query.numberbill, query.courier);
if (getOrderTrackings.ordertracking.status.code == 200) {
var getManifest = getOrderTrackings.ordertracking.result.manifest;
this.setState({ data: getManifest });
}
}
render() {
const { data } = this.state;
console.log(data) // will print 2 values, first condition is empty value, and second condition has values (an example is in the image above)
return (
<div/>
)
}
}

This should do it:
render() {
const { data } = this.state;
if (data.length > 0){
console.log(data)
}
return (
<div/>
)
}

React.js : Updating State of Nested Object

Front End - Front End
Upon clicking the star, I want to update the state of nested object, with the new rating value of star.
I tried many things but it didnt work as states are immutable.
Nested State
Can some upon please suggest how can I update the value in nested object
onStarClicked = (kTypName, subItemId1, newRating) => {
//console.log(subItemId.split("_"));
let evaluation = subItemId1.split("_")[0];
let subItemId = subItemId1.split("_")[1];
console.log(subItemId);
const r = { ...this.state.ratings };
let kT = r.knowledgeTypes;
let sub = '', kTN = '', kIN = '';
kT.map(knowledgeType => {
//console.log(knowledgeType.knowledgeTypeId);
knowledgeType.knowledgeItems.map(knowledgeItem => {
//console.log(knowledgeItem.knowledgeItemId);
knowledgeItem.subItems.map(knowledgeSubItem => {
//console.log(knowledgeSubItem.subItemId);
if (subItemId === knowledgeSubItem.subItemId) {
kTN = knowledgeType.knowledgeTypeName;
kIN = knowledgeItem.knowledgeItemName;
sub = knowledgeSubItem;
if (evaluation === "self") {
sub.evaluation.self.rating = newRating;
}
else if (evaluation === "evaluator") {
sub.evaluation.evaluator.rating = newRating;
}
//alert(evaluation + subItemId + ' ' + newRating);
//return;
}
})
})
});
this.setState({
...this.state,
ratings: {
...this.state.ratings,
knowledgeTypes: [
...this.state.ratings.knowledgeTypes,
this.state.ratings.knowledgeTypes.filter(kt => kt.knowledgeTypeName !== kTN),
{
...this.state.ratings.knowledgeTypes.knowledgeItems.
filter(ki => ki.knowledgeItemName !== kIN),
knowledgeItems: {
...this.state.ratings.knowledgeTypes.knowledgeItems.subItems.
filter(si => si.subItemId !== subItemId),
sub
}
}]
}
});
}

You basically have to create a new empty array of knowledgeTypes and use the current state to find which item of the state you need to change using Object.keys/map/filter functions.
You'd use the current state in a variable and modify that variable only. You'd likely not mess with the actual state object in any way.
After you have done that, simply append it to the empty array. Then you can setState() the new array to the actual state property.
class MyComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
financialYear: "2019-20",
quarter: "Q1",
isCurrentQuarter: true,
knowledgeTypes: [
{
knowledgeTypeName: "Technology",
knowledgeItems: [
{
knowledgeItemName: "Java",
subItems: [
{
subItemId: "2",
subItemName: "Collections",
evaluation: {
self: {
ntnet: "Joe",
rating: 1,
isEditable: true
}
}
}
]
}
]
}
]
};
}
handleClick = e => {
const { knowledgeTypes } = this.state;
// transformation
const itemToChange = knowledgeTypes.map(item => {
if (item.knowledgeTypeName === "Technology") {
return item;
}
});
const currItems = itemToChange[0].knowledgeItems[0].subItems;
const subItem = currItems.map(item => {
if (item.subItemId === "2") {
return item;
}
});
const person = subItem[0].evaluation;
person.self.rating = 55; //change
const newKnowledgeTypes = [];
knowledgeTypes.map(item => {
if (item.knowledgeTypeName === "Technology") {
newKnowledgeTypes.push(itemToChange);
}
newKnowledgeTypes.push(item);
});
this.setState({
knowledgeTypes: newKnowledgeTypes
});
console.log(this.state);
};
render() {
return (
<div>
MyComponent
<button onClick={this.handleClick}>Hello</button>
</div>
);
}
}
The sandbox can be found on https://codesandbox.io/s/musing-dew-8r2vk.
Note: It is advisable you do not use nested state objects because state objects are something more lightweight so that they do not have performance considerations.

import React, { Component } from 'react';
import Auxilary from '../../../hoc/Auxilary/auxilary';
import KnowledgeItems from '../KnowledgeItems/KnowledgeItems';
import Tabs from 'react-bootstrap/Tabs';
import Tab from 'react-bootstrap/Tab';
import knowledge from '../../../assests/staticdata.json';
import './QuarterLog.css';
class QuarterLog extends Component {
constructor() {
super();
this.state = {
"financialYear": "",
"quarter": "",
"isCurrentQuarter": "",
"knowledgeTypes": []
}
}
onStarClicked = (kTypName, kItemName, subItemIdName, newRating) => {
let evaluation = subItemIdName.split("_")[0];
let subItemId = subItemIdName.split("_")[1];
const { knowledgeTypes } = this.state;
// transformation
let knowledgeTypeToChange = knowledgeTypes.map(kType => {
if (kType.knowledgeTypeName === kTypName) {
return kType;
}
});
knowledgeTypeToChange = knowledgeTypeToChange.filter(function (element) {
return element !== undefined;
});
console.log(knowledgeTypeToChange[0]);
let knowledgeItemToChange = knowledgeTypeToChange[0].knowledgeItems.map(item => {
if (item.knowledgeItemName === kItemName) {
return item;
}
});
knowledgeItemToChange = knowledgeItemToChange.filter(function (element) {
return element !== undefined;
});
let knowledgeSubItem = knowledgeItemToChange[0].subItems.map(subItem => {
if (subItem.subItemId === subItemId) {
return subItem;
}
});
knowledgeSubItem = knowledgeSubItem.filter(function (element) {
return element !== undefined;
});
console.log(knowledgeSubItem);
let personEvaluations = knowledgeSubItem[0].evaluation;
if (evaluation === "self") {
personEvaluations.self.rating = newRating.toString(); //change
}
else if (evaluation === "evaluator") {
personEvaluations.evaluator.rating = newRating.toString(); //change
}
const newKnowledgeTypes = [];
knowledgeTypes.map(item => {
if (item.knowledgeTypeName === kTypName) {
newKnowledgeTypes.push(knowledgeTypeToChange[0]);
}
else
newKnowledgeTypes.push(item);
});
this.setState({
knowledgeTypes: newKnowledgeTypes
});
console.log(this.state);
}
componentDidMount() {
// TODO: remove staticdata.js and call REST API and set the response in state
this.setState({
...this.state,
"financialYear": knowledge.financialYear,
"quarter": knowledge.quarter,
"isCurrentQuarter": knowledge.isCurrentQuarter,
"knowledgeTypes": knowledge.knowledgeTypes
})
}
onSubmitRatings = () => {
console.log(this.state);
}
render() {
let data = knowledge; //remove this code, once REST API is implemented
const posts = this.state.knowledgeTypes.map(knowledgeType => {
return (
<Tab key={knowledgeType.knowledgeTypeName} eventKey={knowledgeType.knowledgeTypeName}
title={knowledgeType.knowledgeTypeName}>
<KnowledgeItems
kTypeName={knowledgeType.knowledgeTypeName}
kItems={knowledgeType.knowledgeItems}
ratings={this.state.ratings}
onstarclicked={this.onStarClicked}
/>
</Tab>)
});
return (
<Auxilary>
<div className="d-flex justify-content-between flex-wrap flex-md-nowrap align-items-center pt-3 pb-2 mb-3 border-bottom">
<div><h1>Financial Year : {data.financialYear}</h1></div>
<div><h2>Quarter : {data.quarter}</h2></div>
</div>
<div>
<Tabs defaultActiveKey="Domain" id="uncontrolled-tab-example">
{posts}
</Tabs>
</div>
<button onClick={this.onSubmitRatings}> Submit </button>
</Auxilary>
);
}
}
export default QuarterLog;

React: how to add a spinner after click, and change screen after the animation completes

I saw there are already answered questions on how to add spinners during fetch requests.
However what I need is to stop showing the animation when the animation completes. The animation completes after the timeout is reached.
Also I have a best practice question.
It's a good practice to empty the resources on componentWillUnmount and clear there the timeout. In the code below I clear the timeout in a if condition, because it has to stop as the height of the element reaches the right level.
Is that ok as I did it? If now, how should it look like to have the same functionality in the componentWillUnmount lifecycle phase?
Here is the animation Component:
class Thermometer extends Component {
state = {
termFill : 0
};
componentDidMount() {
const interval = setInterval(() => {
this.setState({
termFill: this.state.termFill + 10
});
if (this.state.termFill === 110) {
window.clearInterval(interval);
}
}, 200)
}
render() {
const styles = {
height: `${this.state.termFill}px`
};
if (this.state.termFill < 100) {
return (
<section>
<div id="therm-fill" style={styles} />
[MORE CODE - SHORTENED FOR EASIER READING]
)
}
};
And here is the Component that has to appear after the animation disappears.
The steps are like this:
A user enter and uses this tool
The user clicks "calculate"
The animation appears instead or on top of the tool
When the animation completes, the animation Component disappears and the tool
is once again visible with its updated state (results of the
calculation).
class DiagnoseTool extends Component {
state = {
[OTHER STATES REMOVED TO KEEP THE CODE SHORTER]
wasBtnClicked: false
};
[OTHER RADIO AND CHECKBOX HANDLERS REMOVED TO KEEP THE CODE SHORTER]
onButtonClick = e => {
e.preventDefault();
this.calculate();
this.setState({
wasBtnClicked: true
})
};
addResult = () => {
const resultColor = {
backgroundColor: "orange"
};
let theResult;
if (this..... [CODE REMOVED TO HAVE THE CODE SHORTER]
return theResult;
};
calculate = () => {
let counter = 0;
let radiocounter = 0;
Object.keys(this.state).filter(el => ['cough', 'nodes', 'temperature', 'tonsillarex'].includes(el)).forEach(key => {
// console.log(this.state[key]);
if (this.state[key] === true) {
counter += 1;
}
});
if (this.state.radioAge === "age14") {
radiocounter++
} else if (this.state.radioAge === "age45") {
radiocounter--
}
if (this.state.radioAge !== "") {
this.setState({
isDisabled: false
})
}
this.setState({
points: counter + radiocounter
});
};
render() {
const {cough, nodes, temperature, tonsillarex, radioAge, wasBtnClicked} = this.state;
return (
<Container>
<BackArrow />
[JSX REMOVED TO KEEP THE CODE SHORTER]
<div className="resultbox">
{
(wasBtnClicked) && this.addResult()
}
</div>
</div>
[HERE IS THE BUTTON]
<button
style={{height: "40px", width: "150px", cursor:"pointer"}}
type="submit"
className="calculateBtn"
onClick={this.onButtonClick}
disabled={!radioAge}
>CALCULATE</button>
</Container>

Add a boolean to your state and set it to false, when the user clicks the button set it to true, after doing the calculation set it to false.
calculate = () => {
let counter = 0;
let radiocounter = 0;
this.setState({
isLoading: true // set is loading to true and show the spinner
})
Object.keys(this.state)
.filter(el =>
["cough", "nodes", "temperature", "tonsillarex"].includes(el)
)
.forEach(key => {
// console.log(this.state[key]);
if (this.state[key] === true) {
counter += 1;
}
});
if (this.state.radioAge === "age14") {
radiocounter++;
} else if (this.state.radioAge === "age45") {
radiocounter--;
}
if (this.state.radioAge !== "") {
this.setState({
isDisabled: false
});
}
this.setState({
points: counter + radiocounter,
isLoading: false // set it to false and display the results of the calculation
});
};
Example
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.0/umd/react-dom.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.21.1/babel.min.js"></script>
<div id="root"></div>
<script type="text/babel">
class App extends React.Component {
timer = null;
constructor() {
super();
this.state = {
result: '',
isLoading: false
};
}
showContent = () => { this.setState({ isLoading: false, result: `7 + 5 = ${7 + 5}` })}
calculate = () => {
this.setState({
isLoading: true,
result: ''
});
this.timer = setTimeout(this.showContent, 5000);
}
componentWillUnmount = () => {
clearTimeout(this.timer);
}
render() {
return (
<div>
<p>7 + 5</p>
<p>{this.state.result}</p>
{ this.state.isLoading
? <p>Calculating...</p>
: <button onClick={this.calculate}>Calculate</button>
}
</div>
);
}
}
ReactDOM.render(
<App />,
document.getElementById('root')
);
</script>

Prop getting lost in unusual situation

I am trying to pass props from my parent component to my child component. When I receive the props in componentWillReceiveProps(), one of the children of my coin prop gets lost. This can be seen with the console.log lines in the child component.
For some reason, coin.profit prints "undefined" while printing just the coin object shows that coin.profit indeed is in the coin object. I have looked over my code for hours now, and asked friends to look at it and to no avail. Any help would be much appreciated.
Child Component (https://github.com/kdelalic/cryptofolio/blob/master/src/js/progress.js):
class Progress extends Component {
constructor(props) {
super(props);
this.state = {
initial: 0,
profit: 0,
holdings: 0,
change: "0%"
};
}
componentWillReceiveProps(nextProps) {
if (nextProps.coins !== this.props.coins) {
Object.keys(nextProps.coins).map((key) => {
const coin = nextProps.coins[key]
console.log(coin)
console.log(coin.price)
console.log(coin.profit)
this.setState({
initial: this.state.initial + coin.price * coin.amount,
profit: this.state.profit,
holdings: this.state.profit + this.state.holdings,
change: this.state.initial / this.state.profit * 100 + "%",
})
})
}
}
Parent Component (https://github.com/kdelalic/cryptofolio/blob/master/src/js/crypto.js):
class Crypto extends Component {
constructor(props) {
super(props);
this.state = {
open: false,
};
}
getCurrentPrice = (key) => {
const { coins } = this.state;
var url = "https://min-api.cryptocompare.com/data/price?fsym=" + coins[key].value.substring(coins[key].value.indexOf("(")+1,coins[key].value.indexOf(")")).toUpperCase() + "&tsyms=" + coins[key].currency.toUpperCase();
axios.get(url)
.then(response => {
const price = response.data[coins[key].currency.toUpperCase()];
const profit = parseFloat((price - coins[key].price) * coins[key].amount).toFixed(2)
var newState = this.state;
newState.coins[key]["currentPrice"] = price;
newState.coins[key]["profit"] = profit;
this.setState(newState);
})
.catch(err => {
console.log(err)
});
};
checkPos = (num) => {
if (num > 0) {
return " positive"
} else if (num < 0) {
return " negative"
} else {
return ""
}
};
handleOpen = () => {
this.setState({ ...this.state, open: true });
};
handleClose = () => {
this.setState({ ...this.state, open: false });
};
coinData = (dataFromChild, key) => {
const newCoins = {
...this.state.coins
};
newCoins[key] = dataFromChild
this.setState({
...this.state,
coins: newCoins
}, () => {
this.getCurrentPrice(key);
this.setState({
...this.state,
})
this.handleClose();
})
};
render() {
const { coins } = this.state;
return (
<div className="crypto">
<Progress coins={this.state.coins}/>

In React, you should never mutate the existing state. In
var newState = this.state;
newState.coins[key]["currentPrice"] = price;
newState.coins[key]["profit"] = profit;
this.setState(newState);
you are never creating any new objects. You should be doing
this.setState({
...this.state,
coins: {
...this.state.coins,
[key]: {
...this.state.coins[key],
currentPrice: price,
profit,
},
},
});
to create new state objects for each item you are mutating.
Because you are modifying the existing object, means the object passed to componentWillReceiveProps will potentially be updated by your other code.