Develop Reference

How to get label values dynamically and adding the numbers together from different input with reactjs

Created a Div and inside it I have label element and input element, I want to get different label values in each div. How to re-use my div component
instead of coding the same code again.
I have tried to search in Stackoverflow plus googles, Haven't received a better answer.
Here I have created div element with just label and input element and then I have rendured this component in App.js file:
How can I reuse the same code/component to create 2 more div and having different labels values in it? Ho can I add numbers together from different input ( which I am getting from different components input)
Appreciate all your help!
import React, { Component } from 'react';
import './calculator.css';
class Boxes extends Component {
state = {
inputOne: '',
inputtwo: '',
inputthree: ''
}
getInputValue = (e) => {
const value = e.target.value;
console.log('value: ', value);
this.setState({
inputOne: Number(e.target.value)
});
}
render() {
const { value } = this.props // destructuring
const {inputOne, inputtwo, inputthree } = this.state
return (
<div className="boxes">
<label className="boxeslevel" htmlFor="text">
{value}
</label>
<input
name="text"
type="text"
onChange={this.getInputValue}
/>
</div>
);
}
}
export default Boxes;
import React, { Component } from 'react';
import './App.css';
import Boxes from './components/calculator';
class App extends Component {
render(){
return (
<div className="wrapper">
<Boxes value= {"Value 1:"} onChange={this.props.onChange}/>
<Boxes value= {"Value 2:"} onChange={this.props.onChange}/>
<Boxes value= {"Value 3:"} onChange={this.props.onChange}/>
<ShowResult />
</div>
);
}
}
export default App;

You should pass a prop to your componente to be reuse. As you notice you are using local component state in your component, like const {value} = this.state try the same approach but with props like const {value} = this.props and then passing that prop in the component usage like
<Boxes value={“label 1”}/>
<Boxes value={“label 2”}/>
That would work. Hope it help you
Remember you can use as many props you need and access them as the same way mention above

You can do something like this:
class Boxes extends Component {
render() {
const { value } = this.props // value coming from props
return (
<div className="wrapper">
<div className="firstBox">
<label htmlFor="text">
{value}
</label>
<input name="text" type="text" />
</div>
</div >
);
}
}
export default Boxes;
and in your app component something like this:
import React, { Component } from 'react';
import './App.css';
import Boxes from './components/calculator';
class App extends Component {
render(){
return (
<div className="App">
<Boxes value={1}/>
<Boxes value={2}/>
<Boxes value={3}/>
</div>
);
}
}
export default App;
Here is live demo link

You have to use props instead of state in your Boxes component. Then you can pass the required props from the App component.
App.js
import React, { Component } from 'react';
import './App.css';
import Boxes from './components/calculator';
class App extends Component {
render(){
return (
<div className="App">
<Boxes value={"Value 1"}/>
<Boxes value={"Value 2"}/>
<Boxes value={"Value 3"}/>
</div>
);
}
}
export default App;
Boxes.js
import React, { Component } from 'react';
import './calculator.css';
class Boxes extends Component {
render() {
const { value } = this.props // destructuring
return (
<div className="wrapper">
<div className="firstBox">
<label htmlFor="text">
{value}
</label>
<input name="text" type="text" />
</div>
</div >
);
}
}
export default Boxes;

React component self close on button click

I have a react component which I want to self close when I click a button that's on the component itself.
Here's the code:
import React from 'react';
import PropTypes from 'prop-types';
const MyReactComponent = (props) => <div>
<h1>TEST</h1>
<button onClick={self close here?}>Self Close</button>
</div>
export default MyReactComponent
How can I get the button click to close the component when I click it?

That's not how React works. :-) Instead, the parent of the component should pass it a property that it uses as the onClick. In response to the click, the parent component changes its state so that the child is no longer rendered:
const MyReactComponent = (props) => <div>
<h1>TEST</h1>
<button onClick={props.onClose}>Self Close</button>
</div>;
class ParentComponent extends React.Component {
// Note: This uses the class fields proposal, currently at Stage 3 and
// commonly transpiled in React projects
closeChild = () => {
this.setState({
showChild: false
});
};
constructor(...args) {
super(...args);
this.state = {
showChild: true
};
}
render() {
return (
<div>
{this.state.showChild && <MyReactComponent onClose={this.closeChild} />}
</div>
);
}
}
ReactDOM.render(
<ParentComponent />,
document.getElementById("root")
);
<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
More in the "Lifting State Up" part of the documentation.

Render a new Component without using router

I've created an application to React, and when it starts, the App component is rendered. I would like that when the user clicks on a button or link, the button or link has to be in the App component when clicking on that link, another component will be rendered but not inside the App component but only the new component will be rendered in the same URL. As for this new component, it has to have a similar button so that when the user clicks, only the App component is rendered and this component that the user has clicked on is not rendered, only the App component.
I do not know if I explained myself correctly. Ask me any question if you need some clarification.
My App component is the following:
import React, { Component } from 'react';
import Touch from './Touch';
import '../App.css';
class App extends Component{
render() {
return(
<div>
<div className="wrapper" >
<button >NewComponent</button><NewComponent />???
<h1>Google Cloud Speech with Socket.io</h1>
<p id="ResultText"><span className="greyText">No Speech to Text yet</span></p>
</div>
<div className="buttonWrapper" >
<button className="btn" id="startRecButton" type="button"> Start recording</button>
<button className="btn" id="stopRecButton" type="button"> Stop recording</button>
</div>
</div>
);
}
}
export default App
My index.js is the following:
import React from 'react';
import ReactDOM from 'react-dom';
import './App.css';
import App from './components/App.js';
import registerServiceWorker from './registerServiceWorker';
ReactDOM.render(<App />, document.getElementById('root'));
registerServiceWorker();

If you really don't want to use react-router you will need to store a value in the component's state and change the rendering method to reflect which button was pressed. If you want each of those component to include the button you need to switch, do the following :
class App extends Component {
constructor(props){
super(props);
this.state = {renderA: false,};
}
handleClick = (event) => {
this.setState((prevState) => ({renderA: !prevState.renderA}));
};
render = () => {
return(
<div>
{this.state.renderA ?
<ComponentA handleClick={this.handleCLick}/>:
<ComponentB handleClick={this.handleCLick}/>
}
</div>
);
};
} export default App;
// ComponentA
class ComponentA extends Component {
render = () => {
return(
<div>
// what you want inside your first page here
<button onClick={this.props.handleClick}
</div>
);
}
} export default ComponentA;
// ComponentB
class ComponentB extends Component {
render = () => {
return(
<div>
// what you want inside your second page here
<button onClick={this.props.handleClick}
</div>
);
}
} export default ComponentB;
But using react-router might also suits your case, and if you are going to write a large app, you should use it instead of rendering differents children components within the same one, based on users inputs.

If the URL stay the same, I don't think React-Router might help you.
If you want that App Component is not loaded, I think you should create two more Component, a Wrapper one, and the new component you want to display (from now on newComponent). What I suggest is:
Creating a property isButtonClicked inside the state of the Wrapper Component;
Creating a function handleButtonClick() inside the Wrapper Component:
handleButtonClick() => {
let isButtonClicked = !this.state.isButtonClicked;
this.setState({ isButtonClicked });
}
In the render() method of the Wrapper component, you write something like this:
render() {
if (this.state.isButtonClicked)
return <App />
else
return <NewComponent />
}
Then, in both App and NewComponent, if you click on the button, you call the this.props.handleButtonClick(), which will lead to a change of the state of Wrapper Component, therefore to a change of what is shown on the screen.

How to make/access state using props in react?

I made an app with multiple components and want their state to be accessed using parent/main app, I'm not sure how to get it. what i'm trying to do is when i change state in main "App" the component state should change. One of the component is 'checkbox' and now i want to access its state using parent app, I made multiple attempts but not getting it done. my code goes like this..
This is Main 'App' code:
import React, { Component } from 'react';
import Checkbox from './checkbox';
import Radio from './Radio';
import ToggleSwitch from './ToggleSwitch';
import PrimaryButton from './PrimaryButton';
class App extends Component {
onClick(isClicked){
isChecked:true
};
render() {
return (
<div id="form">
<Checkbox
onClick={this.onClick}
/>
<RadioButton
onClick={this.onClick}
/>
</div>
);
}
}
export default App;
The component i want to access goes like this:
import React, { Component } from 'react';
class Checkbox extends Component {
constructor(props){
super(props);
this.state={
isChecked:true
};
};
onCheck(){
this.setState({
isChecked: !this.state.isChecked
});
this.props.isClicked()
};
render() {
return (
<div>
<div
className={this.state.isChecked ? 'checked': 'unchecked'}
onClick={this.onCheck.bind(this)}
>
</div>
</div>
);
}
}
export default Checkbox;

You forgot to bind the onClick event in the app component, try this it will work :
class App extends Component {
onClick(isClicked){
console.log('isClicked', isClicked);
};
render() {
return (
<div id="form">
<Checkbox onClick={this.onClick.bind(this)}/>
</div>
);
}
}

If you already have onClick handler for the Checkbox I don't see why you couldn't just move the state up to the App component and just pass down a callback from there to the Checkbox that will update the parent state. That seems like a more React way to do it, to me.
class App extends Component {
constructor(props){
super(props);
this.state={
isChecked:true
}
}
onClick = (isClicked) => {
this.setState({isChecked: !this.state.isChecked})
}
render() {
return (
<div id="form">
<Checkbox
onClick={this.onClick}
ischecked={this.state.isChecked}
/>
</div>
);
}
}
Component
class Checkbox extends Component {
onCheck(){
this.props.onClick()
}
render() {
return (
<div>
<div
className={this.props.isChecked ? 'checked': 'unchecked'}
onClick={this.onCheck.bind(this)}
>
</div>
</div>
)
}
}

How to render component again at the top level with the new props in React 0.14

In the new React.js 0.14 setProps method was deprecated form React.Component. According to documentation, now we should render component again with new props(using ReactDOM.render())
The question is how can I do this? Let's look at an example.
AddTaskForm.js
import React from 'react';
class AddTaskForm extends React.Component
{
onClick() {
this.setProps({
isVisible: false
});
}
render() {
return (
<form role="form">
<div className="row" className={ this.props.isVisible ? 'show' : 'hidden' }>
<input className="form-control" type="text" />
</div>
<button type="button" className="btn" onClick={this.onClick.bind(this)}>Add task</button>
</form>
);
}
}
export default AddTaskForm;
Todo.js
var React = require('react');
var ReactDOM = require('react-dom');
var AddTaskForm = require('./AddTaskForm');
class Todo extends React.Component
{
render() {
return (
<div>
<AddTaskForm isVisible="false"></AddTaskForm>
</div>
);
}
}
ReactDOM.render(<Todo />, document.getElementById('app'));
Btw. I am using ES6 stage 0, if you find yourself confused with syntax
Ok, I can't call setProps, i had to rerender AddTaskForm component in Todo.js. How can I do this in this case? I've read this article form react's blog but wrapper don't really help me.

You should not use setProps at all. Properties in React must be immutable data, so you can't change them. Looks like isVisible prop is really part of component state, because depends on it component decides to show or not to show itself. The best choice for such situations when after some change of data you need to update component is state. I would recommend to read this doc about state and what should and should not go to state
From your example:
<div>
<AddTaskForm isVisible="false"></AddTaskForm>
</div>
.. how do you know should AddTaskForm be visible? For now it's hardcoded. I suggest doing something like that:
render () {
let shouldFormBeVisible = ...// somehow get to know should it be visible or not
return (
<div>
shouldFormBeVisible ? <AddTaskForm /> : null
</div>
)
}
Here is a big advantage: you even don't need to render AddTaskForm and if isVisible is false then hide it. You don't render component if it isn't needed.

isVisible is a piece of mutable state, so it needs to be stored in state somewhere.
One way is to put it on the AddTaskForm:
import React from 'react';
class AddTaskForm extends React.Component
{
constructor(props, context) {
super(props, context);
this.state = { isVisible: true};
}
onClick() {
this.setState({
isVisible: false
});
}
render() {
return (
<form role="form">
<div className="row" className={ this.state.isVisible ? 'show' : 'hidden' }>
<input className="form-control" type="text" />
</div>
<button type="button" className="btn" onClick={this.onClick.bind(this)}>Add task</button>
</form>
);
}
}
export default AddTaskForm;
Todo.js
var React = require('react');
var ReactDOM = require('react-dom');
var AddTaskForm = require('./AddTaskForm');
class Todo extends React.Component
{
render() {
return (
<div>
<AddTaskForm />
</div>
);
}
}
ReactDOM.render(<Todo />, document.getElementById('app'));
Another way is to store it on the Todo component, but I think you have enough to get started.