Develop Reference

React: How to display a default object and highlight li bold?

I am fairly new to React and was wondering if anybody could give me an insight on a problem I am stuck with.
Right now I have a parent(Hello.js) component and two children(Mixer.js and renderCont.js) at the same level.
I am trying to render a list in the Mixer.js and display its corresponding objects in the Hello.js through by passing the values into RenderCont.js. I've gotten to a point where nothing is displayed before I click on any of the list to pass on a object.
From here is where I am stuck: I want the first object of the list to be displayed as a default, at the same time bold the first in the list. And then execute the as I have below.
This is my first time posting a question on stackoverflow so I'm not sure if my question makes sense with the attached codes but I will greatly appreciate any kind of support.
Parent Hello.js:
import React, { Component } from 'react';
import RenderCont from './renderCont.js';
import Mixer from './Mixer';
class Hello extends Component{
constructor(props) {
super(props);
this.state = {
items: [{
id: 0,
name: "First",
background: "white"
}, {
id: 1,
name: "Second",
background: "yellow"
}, {
id: 2,
name: "Third",
background: "blue"
}],
selectedItem: 0
}
this.handle = this.handle.bind(this)
}
handle(value) {
// console.log(this.state.selectedItem);
this.setState({
selectedItem: value
})
}
render() {
const list = this.state.items.map((item) => {
return(item);
})
return (
<div>
<Mixer item={list} onClick={this.handle} selected={this.state.selectedItem}/>
<ul id = "todo" >
<RenderCont item={this.state.selectedItem}/>
</ul>
</div>
)
}
}
export default Hello;
Mixer.js Child1:
import React, { Component } from 'react';
class Mixer extends Component{
constructor(props) {
super(props);
this.state = {
}
this.handleClick = this.handleClick.bind(this);
}
handleClick(item){
this.props.onClick(item);
}
renderTodos(propItems) {
return (
<div>
{propItems.map((item) => (
<li className={this.props.selected === item ? 'media clicked' : 'media'}
key={item.id} onClick = {() => this.handleClick(item)}>
{item.name}
</li>
))}
</div>
)
}
render() {
return (
<div className="yoyoyo">
{this.renderTodos(this.props.item)}
</div>
)
}
}
export default Mixer;
Second Child Comp renderCont.js :
import React, { Component } from 'react';
class RenderCont extends Component{
constructor(props) {
super(props);
}
renderBox(item){
return(
<div style={{color:item.background}}>
{item.id}
{item.name}
</div>
)
}
render() {
return (
<div className="yoyo">
{this.renderBox(this.props.item)}
</div>
)
}
}
export default RenderCont;
and the CSS:
.yoyo{
left: 500px;
background-color:red;
width:500px;
height:500px;
}
.media{
color: black;
}
.clicked{
font-weight: 900;
}
.yoyoyo{
background-color:lightblue;
width:200px;
height:200px;
}

I think the problem is some mismatch between the initial and eventual value of this.props.selected in Mixer.js. You initially set this.state.selectedItem = 0, and this is what is initially passed as the selected prop to Mixer. But the test you apply in that component is
this.props.selected === item ?
While there is one item.id that === 0, there is never an item that === 0. So no items are highlighted at first. But then, once an item is clicked and selectedItem is actually set to an item, the entry is made bold.
So it looks like you need to either make your initial selection equal to the item.id === 0 reference, or consistently refer to items within your components by their id's.

REACT -- adding input toggle in react

I am creating a react app i have to add an input toggle inside my
header component. I tried to add but JavaScript is not working. if
this is the header component file. inside this component I have included my input toggle condition. i have placed JavaScript code right below the imports.
anyone knows please check thanks..
import React, { Component } from 'react';
import PropTypes from 'prop-types';
import {
Nav,
Navbar,
Collapse,
DropdownMenu,
DropdownItem,
NavbarToggler,
DropdownToggle,
UncontrolledDropdown,
} from 'reactstrap';
import { Link, withRouter } from 'react-router-dom';
import Config from '../../../constants/config';
import { SidebarNavItems } from '../Sidebar';
import logoImages from '../../../images/logo.png';
require('./styles.scss');
var allInputs = document.querySelectorAll('.myInput');
allInputs.forEach(function(node) {
node.addEventListener("click", function(){
var allHiddenInputs = document.querySelectorAll('.hidden');
if(allHiddenInputs.length === 0) {
allInputs.forEach(function(input) {
input.classList.add("hidden");
input.classList.add("second");
input.classList.remove("first");
});
node.classList.remove("hidden");
node.classList.remove("second");
node.classList.add("first");
} else {
allHiddenInputs.forEach(function(input) {
input.classList.remove("hidden");
});
}
});
});
class Search extends Component {
constructor(props) {
super(props);
}
render() {
return (
<div className="">
<div className="input-container">
<input type="password" placeholder="Input 1" className="myInput first" />
<input type="password" placeholder="Input 2" className="myInput second hidden" />
</div>
</div>
);
}
}
export default withRouter(Search);
this is my css file which linked to this component.
.input-container {
display: flex;
flex-direction: column;
}
.myInput {
margin: 10px;
padding: 5px
}
.first {
order: 1;
}
.second {
order: 2;
}
.hidden {
display: none;
}
enter image description here

What I would do to simulate the same thing as you are trying to do would be to use local state to update the view. You can conditionally render items as well as class names for each render cycle.
class App extends React.Component {
constructor() {
super()
this.inputNames = ['input1', 'input2']
this.state = {
hiddenInputs: {
input1: { hidden: false, first: true },
input2: { hidden: true, first: false }
},
expanded: false
}
}
handleClick(name) {
const hI = Object.assign({}, this.state.hiddenInputs)
let expanded = this.state.expanded
if (expanded && hI[name].first === true) {
// clicked on the first element, we hide the other
expanded = false
} else if (expanded) {
// clicked on non first item, change order
this.inputNames.forEach(input => {
const isSame = input === name
hI[input].first = isSame
hI[input].hidden = !isSame
})
} else {
// its not open yet, show the other
expanded = true
}
this.setState({expanded, hiddenInputs: hI})
}
render() {
const { input1, input2 } = this.state.hiddenInputs
const {expanded} = this.state
const clsName1 = `myInput${input1.hidden && !expanded ? ' hidden' : ''}${input1.first ? ' first' : ' second'}`;
const clsName2 = `myInput${input2.hidden && !expanded ? ' hidden' : ''}${input2.first ? ' first' : ' second'}`;
return (
<div className="">
<div className="input-container flex">
<input type="password" placeholder="Input 1" onClick={this.handleClick.bind(this, 'input1')} className={clsName1} />
<input type="password" placeholder="Input 2" onClick={this.handleClick.bind(this, 'input2')} className={clsName2} />
</div>
</div>
);
}
}
ReactDOM.render(
<App />,
document.getElementById('container')
);
CSS:
.flex {
display: flex;
}
.first {
order: 0;
}
.second {
order: 1;
}
.hidden {
display: none;
}
Fiddle to see it in action

Try to put your code to component lifecycle (like a componentDidMount), then it would work. But in react it is not good solution to work with DOM nodes directly.
Better way would be to make like that:
class Search extends Component {
constructor(props) {
super(props);
this.state = {allInputsHidden: true}; // You can change it later
}
render() {
return (
<div className="">
<div className="input-container">
<input type="password" placeholder="Input 1" className="myInput first" />
<input type="password" placeholder="Input 2" className={this.state.allInputsHidden ? "myInput second hidden" : "myInput second"} />
</div>
</div>
);
}
}
Also, you can use package classnames to make it look more pretty

You may use state to decide which element to be displayed ...
class Search extends Component {
constructor(props) {
super(props);
this.state = {
toggleInput1:true,
}
render() {
return (
<div className="">
<div className="input-container">
{this.state.toggleInput1?
<input type="password" placeholder="Input 1" className="myInput
first" />:
<input type="password" placeholder="Input 2" className="myInput
second hidden" />
}
</div>
</div>
);
}
}
export default withRouter(Search);
And On EventListener change the state of toogleInput
handleClick = event => {
this.setState({toggleInput1:!this.state.toggleInput1 });
};

Use conditional rendering to achieve this task. You can refer this page. Create your input group as a component and add a boolean prop to use with if condition. This is much better than adding classes.
function Inputs(props) {
const isFirst = props.isFirst;
if (isFirst) {
return <input type="password" placeholder="Input 1" className="myInput first" />;
}
return <input type="password" placeholder="Input 2" className="myInput second" />;
}
ReactDOM.render(
<Inputs isFirst={true} />,
document.getElementById('root')
);
And add a click event to toggle the value of isFirst variable.

React list choosing option

I have an location app which can save name of locations.
I am trying to get each saved location a red border by clicking on it.
What it does is changing the border color of all the categories.
How can I apply that?
class Categories extends Component {
constructor(props) {
super(props);
this.state = {
term: '',
categories: [],
selectedCategories: [],
hidden: true,
checkboxState: true
};
}
toggle(e) {
this.setState({
checkboxState: !this.state.checkboxState
})
}
onChange = (event) => {
this.setState({ term: event.target.value });
}
addCategory = (event) => {
if (this.state.term === '') {
alert('Please name your category!')
} else {
event.preventDefault();
this.setState({
term: '',
categories: [...this.state.categories, this.state.term]
});
}
}
render() {
return (
<div className="categories">
<h1>Categories</h1>
<div className='actions'>
<button className="delete" onClick={this.deleteCategory}>Delete</button>
<button className="edit" onClick={this.editCategory}>Edit</button>
</div>
<p>To add new category, please enter category name</p>
<form className="App" onSubmit={this.addCategory}>
<input value={this.state.term} onChange={this.onChange} />
<button>Add</button>
</form>
{this.state.categories.map((category, index) =>
<button
key={index}
style={this.state.checkboxState ? { borderColor: '' } : { borderColor: 'red' }}
checked={this.state.isChecked}
onClick={this.toggle.bind(this)}>
{category}</button>
)}
</div >
);
}
}
I want to be able to control each selected category seperatly, to be able to delete and edit theme as well.

You can set the state based on index and retrieve the similar way,
Code:
{this.state.categories.map((category, index) =>
<button
key={index}
id={`checkboxState${index}`}
style={!this.state[`checkboxState${index}`] ?
{ borderColor: '' } : { border: '2px solid red' }}
checked={this.state.isChecked}
onClick={this.toggle}>
{category}</button>
)}
You can see how I am checking the state dynamically this.state[`checkboxState${index}`] and also I have assigned an id to it.
In toggle method:
toggle = (e) => {
const id = e.target.id;
this.setState({
[id]: !this.state[id]
})
}
FYI, this is a working code, you can see it
https://codesandbox.io/s/vy3r73jkrl
Let me know if this helps you :)

Here's a really bad example using react. I'd more than likely use this.props.children instead of just cramming them in there. This would allow it to be more dynamic. And instead of using state names we could then just use indexes. But you'll observe, that the parent container decides which child is red by passing a method to each child. On click, the child fires the method from the parent. How you implement it can vary in a million different ways, but the overall idea should work.
class ChildContainer extends React.Component
{
constructor(props)
{
super(props);
}
render() {
let color = this.props.backgroundColor;
return(
<section
className={'child'}
style={{backgroundColor: color}}
onClick={this.props.selectMe}
>
</section>
)
}
}
class Parent extends React.Component
{
constructor(props)
{
super(props)
this.state = {
first : 'Pink',
second : 'Pink',
third : 'Pink',
previous: null
}
this.updateChild = this.updateChild.bind(this);
}
updateChild(name)
{
let {state} = this;
let previous = state.previous;
if(previous)
{
state[previous] = 'Pink';
}
state[name] = 'Red';
state.previous = name;
this.setState(state);
}
render()
{
console.log(this)
return(
<section id={'parent'}>
<ChildContainer
selectMe={() => this.updateChild('first')}
backgroundColor = {this.state.first}
/>
<ChildContainer
selectMe={() => this.updateChild('second')}
backgroundColor = {this.state.second}
/>
<ChildContainer
selectMe={() => this.updateChild('third')}
backgroundColor = {this.state.third}
/>
</section>
)
}
}
class App extends React.Component
{
constructor(props)
{
super(props)
}
render()
{
return(
<section>
<Parent/>
</section>
)
}
}
React.render(<App />, document.getElementById('root'));

You need to track the state of every checkbox, possibly have an array with all currently checked checkboxes.
Then instead of this.state.checkboxState in this.state.checkboxState ? { borderColor: '' } : { borderColor: 'red' } you need to check if current category is in the currently checked categories array.
Hope this helps

Referencing data in stateless React components

I made a stateless component with an internal variable to reference an input, as below. This is working fine.
const MyStatelessComp = ({ team, teamProgress, onSet, editing, enableEdit }) => {
let input
return (
<div>
<div className="team__goal-target_header" >Team's Savings Target</div>
<div className="team__goal-target_value" >
M$
<input
ref={ el => input = el }
style={{width: '75px', border: 'none'}}
onChange={() => onSet({teamId: team.id, goalValue: parseInt(input.value, 10) || 0}) }
/>
<div
ref={ el => input }
style={{
display: !input || (!isNaN(parseFloat(input.value)) && isFinite(input.value)) ? 'none' : 'block'
}}
>Must be numeric</div>
</div>
</div>
)
}
I want to validate input and display a notification Must be numeric is the anything that cannot be converted to a number is entered into my input field. That is not working however. How do I make input in the context of the "warning div" reference the value of the input?
Realize that this is not an unorthodox way to working with stateless components, but it would save me lots of pain.
Thank you.

Why use a stateless component when he can be a simple statefull component ?
class App extends Component {
constructor(props) {
super(props);
this.state = {
value: null
};
this.handleChange = this.handleChange.bind(this);
}
handleChange(event) {
this.setState({ value: event.target.value });
}
render() {
const isNumber = !isNaN(this.state.value);
return (
<div>
<div className="team__goal-target_header">Team's Savings Target</div>
<div className="team__goal-target_value">
M$
<input
style={{ width: "75px", border: "none" }}
onChange={this.handleChange}
value={this.state.value}
/>
{isNumber ? "" : <div>Must be numeric</div>}
</div>
</div>
);
}
}
You can also toggle the div content or create a new alert component and toggle this component.

Toggle active class on child components

I'm having a bit of a head ache trying to figure out the React way of implementing this.
I have a Searches component which houses SearchItems, when an item is clicked among other things I need to set it's state to active to that it gets the correct CSS, I managed to get this working fine but how would I go about removing the active state from the others?
I was thinking that I could pass down a function from the top level component that would take the ID of the search, when clicked it'd zip through SearchItems and change their state to either true/false depending on which ID it was?
Code below!
Top level component:
import React from "react";
import {Link} from "react-router";
import Search from "./Search";
export default class Searches extends React.Component {
constructor(){
super();
this.state = {
searches : [
{
id : "2178348216",
searchName: "searchName1",
matches: "5"
},
{
id : "10293840132",
searchName: "searchName2",
matches: "20"
}
]
};
}
render() {
const { searches } = this.state;
const SearchItems = searches.map((search) => {
return <Search key={search.id} {...search}/>
})
return (
<div> {SearchItems} </div>
);
}
}
Search items component
export default class Search extends React.Component {
constructor() {
super();
// Set the default panel style
this.state = {
panelStyle: { height: '90px', marginBottom: '6px', boxShadow: '' },
selected: false
}
}
isActive(){
return 'row panel panel-success ' + (this.state.selected ? 'active' : 'default');
}
viewNotifications(e){
this.setState({selected: true});
}
render() {
const { id, searchName, matches } = this.props;
const buttonStyle = {
height: '100%',
width: '93px',
backgroundColor: '#FFC600'
}
return (
<div style={this.state.panelStyle} className={this.isActive()}>
<div class="col-xs-10">
<div class="col-xs-7">
Search Name: {searchName}
</div>
<div class="col-xs-7">
Must Have: PHP, MySQL
</div>
<div class="col-xs-7">
Could Have: AngularJS
</div>
</div>
<button type="button" onClick={this.viewNotifications.bind(this)} style={buttonStyle} class="btn btn-default btn-lg"> {matches} </button>
</div>
);
}
}

I think you don't need the state in the child component at all. In fact is a good idea to avoid having state in most components so they are easy to reason and reuse.
I would leave all the state only on the parent component in this case.
TOP Component:
import React from "react";
import Search from "./search";
export default class Searches extends React.Component {
constructor(){
super();
this.state = {
searches : [
{
id : "2178348216",
searchName: "searchName1",
matches: "5"
},
{
id : "10293840132",
searchName: "searchName2",
matches: "20"
}
],
activeElement : null
};
}
_onSearchSelect(searchId) {
this.setState({'activeElement': searchId})
}
render() {
const { searches, activeSearchId } = this.state;
const SearchItems = searches.map((search) => {
return <Search key={search.id} {...search}
isActive={search.id === activeElement}
onSelect={this._onSearchSelect.bind(this)} />
})
return (
<div> {SearchItems} </div>
);
}
}
CHILD Component:
import React from "react";
export default class Search extends React.Component {
_getPanelClassNames() {
const { isActive } = this.props
return 'row panel panel-success ' + (isActive ? 'active' : 'default')
}
_onSelect() {
const { id, onSelect } = this.props;
onSelect(id)
}
render() {
const { searchName, matches } = this.props;
const panelStyle = { height: '90px', marginBottom: '6px', boxShadow: '' }
const buttonStyle = {
height: '100%',
width: '93px',
backgroundColor: '#FFC600'
}
return (
<div style={panelStyle} className={this._getPanelClassNames()}>
<div className="col-xs-4">
Search Name: {searchName}
</div>
<div className="col-xs-3">
Must Have: PHP, MySQL
</div>
<div className="col-xs-3">
Could Have: AngularJS
</div>
<div className="col-xs-2">
<button type="button" onClick={this._onSelect.bind(this)}
style={buttonStyle} className="btn btn-default btn-lg"
>
{matches}
</button>
</div>
</div>
);
}
}
You can also see it running in Plunker: https://plnkr.co/edit/sdWzFedsdFx4MpbOuPJD?p=preview

Ok it turns out this is simpler than I thought and is simply a case of understanding how react works(and not getting confused) .
When you have a top level component you pass it's state via props to children, when you update the state in the top level component it'll pass that down to the children and you can use componentWillReceiveProps to take action.
I added a function to my top level component called updateActiveSearch which simply sets the state of the TOP level component I then passed the activeElement state as a prop to the child Elements along with the function. When a child element calls this function to set itself as active all of them will fire componentWillReceiveProps, they simply just need to check their own ID against the one they've received, if it matches they're active, if it doesn't they're not!
So my top level component now looks like this:
export default class Searches extends React.Component {
constructor(){
super();
this.state = {
searches : [
{
id : "2178348216",
searchName: "searchName1",
matches: "5"
},
{
id : "10293840132",
searchName: "searchName2",
matches: "20"
}
],
activeElement : 0
};
}
// This function gets passed via a prop below
updateActiveSearch(id){
//console.log(id);
this.setState({activeElement : id});
}
render() {
const SearchItems = this.state.searches.map((search) => {
return <Search activeElement={this.state.activeElement} goFunction={this.updateActiveSearch.bind(this)} key={search.id} {...search}/>
})
return (
<div> {SearchItems} </div>
);
}
}
CHILD COMPONENTS
export default class Search extends React.Component {
constructor() {
super();
// Set the default panel style
this.state = {
panelStyle: { height: '90px', marginBottom: '6px', boxShadow: '' },
selected: false
}
}
// This happens right before the props get updated!
componentWillReceiveProps(incomingProps){
if(incomingProps.activeElement == this.props.id){
this.setState({selected: true});
} else {
this.setState({selected: false});
}
}
isActive(){
return 'row panel panel-success ' + (this.state.selected ? 'active' : 'default');
}
viewNotifications(e){
//this.state.panelStyle.boxShadow = '-2px 3px 20px 5px rgba(255,198,0,1)';
this.setState({selected: true});
this.props.goFunction(this.props.id);
}
render() {
const { id, searchName, matches } = this.props;
const buttonStyle = {
height: '100%',
width: '93px',
backgroundColor: '#FFC600'
}
return (
<div style={this.state.panelStyle} className={this.isActive()}>
<div class="col-xs-10">
<div class="col-xs-7">
Search Name: {searchName}
</div>
<div class="col-xs-7">
Must Have: PHP, MySQL
</div>
<div class="col-xs-7">
Could Have: AngularJS
</div>
</div>
<button type="button" onClick={this.viewNotifications.bind(this)} style={buttonStyle} class="btn btn-default btn-lg"> {matches} </button>
</div>
);
}
}