ReactJS - How to get focus on component after make visible - javascript

I had a <div> with a <p> child component I name SocialPostwithCSS, and onClick would cause it to hide, change the state to editing: true and a <textarea> would show up and I would use this.textarea.focus with the textarea having ref={(input)=>{this.textarea=input}} and had no problem.
I needed to autosize the area, so I downloaded the NPM package TextareaAutosize, now I'm having issues focusing on this text area. I check, the npm TextareAutosize file has class and is not stateless. Currently this.textarea is returning undefined
Summary: How can I focus on <TextareaAutosize /> after <div> onClick
which causes the state change to show <TextareaAutosize>?
File Below:
import React, { Component } from 'react'
import SocialPostWithCSS from './SocialPostWithCSS'
import TextareaAutosize from 'react-autosize-textarea'
class SocialPost extends Component {
constructor(props) {
super(props)
this.state = {
message: this.props.socialPost.message,
editing: false
}
}
_clickToEdit() {
this.textarea.focus()
}
render() {
return (
<div>
{(!this.state.editing) ?
<div onClick={async ()=>{await this.setState({editing: true});this._clickToEdit}}>
<SocialPostWithCSS >{this.state.message}</SocialPostWithCSS>
</div>
:<div>
<TextareaAutosize
onBlur={() => {this.setState({ editing: false})}}
type='text'
ref={(input)=>{this.textarea=input}}
value={this.state.message}
/>
</div>
}
</div>
)
}
}
export default SocialPost

From looking at the code, it appears that TextareaAutosize exposes the inner ref through a prop named innerRef. So change your code like this:
<TextareaAutosize
onBlur={() => {this.setState({ editing: false})}}
type='text'
innerRef={(input)=>{this.textarea=input}}
value={this.state.message}
/>

this.textarea is returning undefined onclick to the div because initially when this.state.editing is false TextareaAutosize component was not rendered and hence this.textarea was not initialized by the mounted instance of the component.

Related

Modal Not Appearing onClick

I am creating a modal in React that will allow users to add an item to a table. I create a RecipeModal component with a form inside, and I receive no errors when compiling, yet nothing happens when I click the button. I followed a tutorial very closely and have run out of ideas. I've seen people have issues with 'fade' in React that turns the modal completely clear and therefor invisible, but I tried checking in "Inspect" (DevTools? I'm am not sure what it is called) for 'modal' and didn't see it there. I am very new to web developing, so let me know if I should attach something else. I had more input field, but removed them while trying to fix this.
import React, { Component } from 'react';
import { Button, Modal, ModalHeader, ModalBody, Form, FormGroup, Label, Input } from 'reactstrap';
import { connect } from 'react-redux';
import { addRecipe } from '../action/recipeActions';
class RecipeModal extends Component {
state = {
modal: false,
recipe_name: '',
recipe_description: '',
recipe_ingredients: '',
recipe_steps: ''
}
toggle = (e) => {
this.setState({
modal: !this.state.modal
});
}
onChange = (e) => {
this.setState(
{ [e.target.recipe_name]: e.target.value }
);
}
render() {
return (
<div>
<Button
color="dark"
style={{ marginBotton: '2rem' }}
onClick={this.toggle}
>Add Recipe</Button>
<Modal
isOpen={this.state.Modal}
toggle={this.toggle} >
<ModalHeader toggle={this.toggle}>Add a New Recipe</ModalHeader>
<ModalBody>
<Form onSubmit={this.onSubmit}>
<FormGroup>
<Label for="recipe">Recipe</Label>
<Input
type="text"
recipe_name="recipe_name"
id="recipe"
placeholder="Add recipe name"
OnChange={this.onChange} />
</FormGroup>
</Form>
</ModalBody>
</Modal>
</div>
);
}
}
export default connect()(RecipeModal);
State is case-sensitive. So it's either you rename your modal state to Modal
state = {
Modal: false,
...
};
or refactor the isOpen prop to <Modal isOpen={this.state.modal} toggle={this.toggle}>
I suggest the latter.

How to focus a specific component on page load in React using hooks? [duplicate]

What's the react way of setting focus on a particular text field after the component is rendered?
Documentation seems to suggest using refs, e.g:
Set ref="nameInput" on my input field in the render function, and then call:
this.refs.nameInput.getInputDOMNode().focus();
But where should I call this? I've tried a few places but I cannot get it to work.
#Dhiraj's answer is correct, and for convenience you can use the autoFocus prop to have an input automatically focus when mounted:
<input autoFocus name=...
Note that in jsx it's autoFocus (capital F) unlike plain old html which is case-insensitive.
You should do it in componentDidMount and refs callback instead. Something like this
componentDidMount(){
this.nameInput.focus();
}
class App extends React.Component{
componentDidMount(){
this.nameInput.focus();
}
render() {
return(
<div>
<input
defaultValue="Won't focus"
/>
<input
ref={(input) => { this.nameInput = input; }}
defaultValue="will focus"
/>
</div>
);
}
}
ReactDOM.render(<App />, document.getElementById('app'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.1/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.1/react-dom.js"></script>
<div id="app"></div>
Focus on mount
If you just want to focus an element when it mounts (initially renders) a simple use of the autoFocus attribute will do.
<input type="text" autoFocus />
Dynamic focus
to control focus dynamically use a general function to hide implementation details from your components.
React 16.8 + Functional component - useFocus hook
const FocusDemo = () => {
const [inputRef, setInputFocus] = useFocus()
return (
<>
<button onClick={setInputFocus} >
Focus
</button>
<input ref={inputRef} />
</>
)
}
const useFocus = () => {
const htmlElRef = useRef(null)
const setFocus = () => {htmlElRef.current && htmlElRef.current.focus()}
return [ htmlElRef, setFocus ]
}
Full Demo
React 16.3 + Class Components - utilizeFocus
class App extends Component {
constructor(props){
super(props)
this.inputFocus = utilizeFocus()
}
render(){
return (
<>
<button onClick={this.inputFocus.setFocus}>
Focus
</button>
<input ref={this.inputFocus.ref}/>
</>
)
}
}
const utilizeFocus = () => {
const ref = React.createRef()
const setFocus = () => {ref.current && ref.current.focus()}
return {setFocus, ref}
}
Full Demo
As of React 0.15, the most concise method is:
<input ref={input => input && input.focus()}/>
If you just want to make autofocus in React, it's simple.
<input autoFocus type="text" />
While if you just want to know where to put that code, answer is in componentDidMount().
v014.3
componentDidMount() {
this.refs.linkInput.focus()
}
In most cases, you can attach a ref to the DOM node and avoid using findDOMNode at all.
Read the API documents here: https://facebook.github.io/react/docs/top-level-api.html#reactdom.finddomnode
React 16.3 added a new convenient way to handle this by creating a ref in component's constructor and use it like below:
class MyForm extends Component {
constructor(props) {
super(props);
this.textInput = React.createRef();
}
componentDidMount() {
this.textInput.current.focus();
}
render() {
return(
<div>
<input ref={this.textInput} />
</div>
);
}
}
For more details about React.createRef, you can check this article in React blog.
Update:
Starting from React 16.8, useRef hook can be used in function components to achieve the same result:
import React, { useEffect, useRef } from 'react';
const MyForm = () => {
const textInput = useRef(null);
useEffect(() => {
textInput.current.focus();
}, []);
return (
<div>
<input ref={textInput} />
</div>
);
};
The React docs now have a section for this. https://facebook.github.io/react/docs/more-about-refs.html#the-ref-callback-attribute
render: function() {
return (
<TextInput
ref={function(input) {
if (input != null) {
input.focus();
}
}} />
);
},
I just ran into this issue and I'm using react 15.0.1 15.0.2 and I'm using ES6 syntax and didn't quite get what I needed from the other answers since v.15 dropped weeks ago and some of the this.refs properties were deprecated and removed.
In general, what I needed was:
Focus the first input (field) element when the component mounts
Focus the first input (field) element with an error (after submit)
I'm using:
React Container/Presentation Component
Redux
React-Router
Focus the First Input Element
I used autoFocus={true} on the first <input /> on the page so that when the component mounts, it will get focus.
Focus the First Input Element with an Error
This took longer and was more convoluted. I'm keeping out code that isn't relevant to the solution for brevity.
Redux Store / State
I need a global state to know if I should set the focus and to disable it when it was set, so I don't keep re-setting focus when the components re-render (I'll be using componentDidUpdate() to check for setting focus.)
This could be designed as you see fit for you application.
{
form: {
resetFocus: false,
}
}
Container Component
The component will need to have the resetfocus property set and a callBack to clear the property if it ends up setting focus on itself.
Also note, I organized my Action Creators into separate files mostly due to my project is fairly large and I wanted to break them up into more manageable chunks.
import { connect } from 'react-redux';
import MyField from '../presentation/MyField';
import ActionCreator from '../actions/action-creators';
function mapStateToProps(state) {
return {
resetFocus: state.form.resetFocus
}
}
function mapDispatchToProps(dispatch) {
return {
clearResetFocus() {
dispatch(ActionCreator.clearResetFocus());
}
}
}
export default connect(mapStateToProps, mapDispatchToProps)(MyField);
Presentation Component
import React, { PropTypes } form 'react';
export default class MyField extends React.Component {
// don't forget to .bind(this)
constructor(props) {
super(props);
this._handleRef = this._handleRef.bind(this);
}
// This is not called on the initial render so
// this._input will be set before this get called
componentDidUpdate() {
if(!this.props.resetFocus) {
return false;
}
if(this.shouldfocus()) {
this._input.focus();
this.props.clearResetFocus();
}
}
// When the component mounts, it will save a
// reference to itself as _input, which we'll
// be able to call in subsequent componentDidUpdate()
// calls if we need to set focus.
_handleRef(c) {
this._input = c;
}
// Whatever logic you need to determine if this
// component should get focus
shouldFocus() {
// ...
}
// pass the _handleRef callback so we can access
// a reference of this element in other component methods
render() {
return (
<input ref={this._handleRef} type="text" />
);
}
}
Myfield.propTypes = {
clearResetFocus: PropTypes.func,
resetFocus: PropTypes.bool
}
Overview
The general idea is that each form field that could have an error and be focused needs to check itself and if it needs to set focus on itself.
There's business logic that needs to happen to determine if the given field is the right field to set focus to. This isn't shown because it will depend on the individual application.
When a form is submitted, that event needs to set the global focus flag resetFocus to true. Then as each component updates itself, it will see that it should check to see if it gets the focus and if it does, dispatch the event to reset focus so other elements don't have to keep checking.
edit
As a side note, I had my business logic in a "utilities" file and I just exported the method and called it within each shouldfocus() method.
Cheers!
This is not longer the best answer. As of v0.13, this.refs may not available until AFTER componentDidMount() runs, in some odd cases.
Just add the autoFocus tag to your input field, as FakeRainBrigand showed above.
Ref. #Dave's comment on #Dhiraj's answer; an alternative is to use the callback functionality of the ref attribute on the element being rendered (after a component first renders):
<input ref={ function(component){ React.findDOMNode(component).focus();} } />
More info
Using React Hooks / Functional components with Typescript, you can use the useRef hook with HTMLInputElement as the generic parameter of useRef:
import React, { useEffect, useRef } from 'react';
export default function MyComponent(): JSX.Element {
const inputReference = useRef<HTMLInputElement>(null);
useEffect(() => {
inputReference.current?.focus();
}, []);
return (
<div>
<input ref={inputReference} />
</div>
);
}
Or if using reactstrap, supply inputReference to innerRef instead of ref:
import React, { useEffect, useRef } from 'react';
import { Input } from 'reactstrap';
export default function MyComponent(): JSX.Element {
const inputReference = useRef<HTMLInputElement>(null);
useEffect(() => {
inputReference.current?.focus();
}, []);
return (
<div>
<Input innerRef={inputReference} />
</div>
);
}
Note that none of these answers worked for me with a material-ui TextField component. Per How to set focus to a materialUI TextField? I had to jump through some hoops to get this to work:
const focusUsernameInputField = input => {
if (input) {
setTimeout(() => {input.focus()}, 100);
}
};
return (
<TextField
hintText="Username"
floatingLabelText="Username"
ref={focusUsernameInputField}
/>
);
This is the proper way, how to autofocus. When you use callback instead of string as ref value, it is automatically called. You got your ref available than without the need of touching the DOM using getDOMNode
render: function() {
return <TextInput ref={(c) => this._input = c} />;
},
componentDidMount: function() {
this._input.focus();
},
You don't need getInputDOMNode?? in this case...
Just simply get the ref and focus() it when component gets mounted -- componentDidMount...
import React from 'react';
import { render } from 'react-dom';
class myApp extends React.Component {
componentDidMount() {
this.nameInput.focus();
}
render() {
return(
<div>
<input ref={input => { this.nameInput = input; }} />
</div>
);
}
}
ReactDOM.render(<myApp />, document.getElementById('root'));
You can put that method call inside the render function. Or inside the life cycle method, componentDidUpdate
I have same problem but I have some animation too, so my colleague suggest to use window.requestAnimationFrame
this is ref attribute of my element:
ref={(input) => {input && window.requestAnimationFrame(()=>{input.focus()})}}
AutoFocus worked best for me. I needed to change some text to an input with that text on double click so this is what I ended up with:
<input autoFocus onFocus={this.setCaretToEnd} value={this.state.editTodo.value} onDoubleClick={this.updateTodoItem} />
NOTE: To fix the issue where React places the caret at the beginning of the text use this method:
setCaretToEnd(event) {
var originalText = event.target.value;
event.target.value = '';
event.target.value = originalText;
}
Found here:
https://coderwall.com/p/0iz_zq/how-to-put-focus-at-the-end-of-an-input-with-react-js
<input type="text" autoFocus />
always try the simple and basic solution first, works for me.
To move focus to a newly created element, you can store the element's ID in the state and use it to set autoFocus. e.g.
export default class DefaultRolesPage extends React.Component {
addRole = ev => {
ev.preventDefault();
const roleKey = this.roleKey++;
this::updateState({
focus: {$set: roleKey},
formData: {
roles: {
$push: [{
id: null,
name: '',
permissions: new Set(),
key: roleKey,
}]
}
}
})
}
render() {
const {formData} = this.state;
return (
<GridForm onSubmit={this.submit}>
{formData.roles.map((role, idx) => (
<GridSection key={role.key}>
<GridRow>
<GridCol>
<label>Role</label>
<TextBox value={role.name} onChange={this.roleName(idx)} autoFocus={role.key === this.state.focus}/>
</GridCol>
</GridRow>
</GridSection>
))}
</GridForm>
)
}
}
This way none of the textboxes get focus on page load (like I want), but when you press the "Add" button to create a new record, then that new record gets focus.
Since autoFocus doesn't "run" again unless the component gets remounted, I don't have to bother unsetting this.state.focus (i.e. it won't keep stealing focus back as I update other states).
Simple solution without autofocus:
<input ref={ref => ref && ref.focus()}
onFocus={(e)=>e.currentTarget.setSelectionRange(e.currentTarget.value.length, e.currentTarget.value.length)}
/>
ref triggers focus, and that triggers onFocus to calculate the end and set the cursor accordingly.
Ben Carp solution in typescript
React 16.8 + Functional component - useFocus hook
export const useFocus = (): [React.MutableRefObject<HTMLInputElement>, VoidFunction] => {
const htmlElRef = React.useRef<HTMLInputElement>(null);
const setFocus = React.useCallback(() => {
if (htmlElRef.current) htmlElRef.current.focus();
}, [htmlElRef]);
return React.useMemo(() => [htmlElRef, setFocus], [htmlElRef, setFocus]);
};
Warning: ReactDOMComponent: Do not access .getDOMNode() of a DOM node; instead, use the node directly. This DOM node was rendered by App.
Should be
componentDidMount: function () {
this.refs.nameInput.focus();
}
The simplest answer is add the ref="some name" in the input text element and call the below function.
componentDidMount(){
this.refs.field_name.focus();
}
// here field_name is ref name.
<input type="text" ref="field_name" />
After trying a lot of options above with no success I've found that It was as I was disabling and then enabling the input which caused the focus to be lost.
I had a prop sendingAnswer which would disable the Input while I was polling the backend.
<Input
autoFocus={question}
placeholder={
gettingQuestion ? 'Loading...' : 'Type your answer here...'
}
value={answer}
onChange={event => dispatch(updateAnswer(event.target.value))}
type="text"
autocomplete="off"
name="answer"
// disabled={sendingAnswer} <-- Causing focus to be lost.
/>
Once I removed the disabled prop everything started working again.
Read almost all the answer but didnt see a getRenderedComponent().props.input
Set your text input refs
this.refs.username.getRenderedComponent().props.input.onChange('');
According to the updated syntax, you can use this.myRref.current.focus()
Focus using createRef for functional components
To developers using Functional Components. This seems to suit. Focus happens on inputfield after clicking on the button. I've attached CodeSandbox link too.
import React from 'react';
export default function App() {
const inputRef = React.createRef();
return <>
<input ref={inputRef} type={'text'} />
<button onClick={() => {if (inputRef.current) { inputRef.current.focus() }}} >
Click Here
</button>
</>
}
https://codesandbox.io/s/blazing-http-hfwp9t
That one worked for me:
<input autoFocus={true} />
Updated version you can check here
componentDidMount() {
// Focus to the input as html5 autofocus
this.inputRef.focus();
}
render() {
return <input type="text" ref={(input) => { this.inputRef = input }} />
})
Since there is a lot of reasons for this error I thought that I would also post the problem I was facing. For me, problem was that I rendered my inputs as content of another component.
export default ({ Content }) => {
return (
<div className="container-fluid main_container">
<div className="row">
<div className="col-sm-12 h-100">
<Content /> // I rendered my inputs here
</div>
</div>
</div>
);
}
This is the way I called the above component:
<Component Content={() => {
return (
<input type="text"/>
);
}} />

How to get value from element in react js?

This is my very first app in React. I have created the component and when a user adds text to textArea and clicks on the button, "Download Pdf", I want to pass defaultValue to convertToPdf function.
How do i do that? Basically, I am trying to create a PDF downloader. Any help will be appreciated.
pdfComponent.js
import React, { Component } from "react";
import autosize from "autosize";
import Button from '#material-ui/core/Button';
export class PDFEditorComponent extends Component {
componentDidMount() {
this.textarea.focus();
autosize(this.textarea);
}
convertToPdf() {
this.setState(this.textarea);
console.log("TEXT", this.textarea);
}
render() {
const style = {
maxHeight: "175px",
minHeight: "450px",
minWidth: "800px",
resize: "none",
padding: "9px",
boxSizing: "border-box",
fontSize: "15px"
};
return (
<div>
PDF Downloader
<br />
<br />
<textarea
style={style}
ref={c => (this.textarea = c)}
placeholder="Paste pdf data"
rows={1}
defaultValue=""
/>
<br />
<Button
variant="contained"
color="primary"
onClick={() => this.convertToPdf(this.textarea)}
>
Download Pdf
</Button>
</div>
);
}
}
Bulletpoints:
Actually create a ref for your textarea (in constructor)
constructor(props) {
super(props);
this.textareaRef = React.createRef();
}
then pass it to your textarea element like this
ref={this.textareaRef}
In your convertToPdf() use it like so
this.setState({value: this.textareaRef.current.value})
React state consists of key-value pairs, so you should initialize it in constructor like so
this.state = {
value: null;
}
and then whenever you want to change it (only from within this component), you call setState(), like I did in p. 2
You are mixing html elements with JS variables: you can't call this.textarea, because it's not a variable (nor constant), so remove all such references to it. In React the only way to access DOM elements is by refs (which you already kind of tried, I corrected you in p. 1).
Enjoy React, it's great :)

Pass Argument to Function Reactjs

I am building a tab bar using react-mdl library. I have an activeTab property in my state object to determine which tab was clicked and render the right information.
I have used an onChange method on the tabs holder to fetch the tab id from user click events and passed the id to my function where the activeTab property will be set from events.
This is what I have done so far:
import React, { Component } from 'react';
import { Tabs, Tab } from 'react-mdl';
import './index.css';
class Projects extends Component {
constructor(props){
super(props);
this.state = {
activeTab: 0
}
}
handleTabChange(tabId){
this.setState({
activeTab: tabId
});
console.log(this.state);
}
render() {
return (
<div className="">
<Tabs
activeTab={this.state.activeTab}
onChange={ () => this.handleTabChange(tabId)}>
<Tab>Android</Tab>
<Tab>Web</Tab>
<Tab>Full Stack</Tab>
</Tabs>
</div>
);
}
}
export default Projects;
but when I build the project it crashes in browser with this error:
./src/components/Projects/Projects.js
Line 28: 'tabId' is not defined no-undef
Search for the keywords to learn more about each error.
How can I fix this? Thank you.
You are almost there. From the react-mdl examples:
You need to pass the tabId as a parameter to the onChange binding.
onChange={ (tabId) => this.handleTabChange(tabId)}
Full example:
<div className="demo-tabs">
<Tabs activeTab={this.state.activeTab}
onChange={(tabId) => this.setState({ activeTab: tabId })} ripple>
<Tab>Starks</Tab>
<Tab>Lannisters</Tab>
<Tab>Targaryens</Tab>
</Tabs>
<section>
<div className="content">Content for the tab: {this.state.activeTab}</div>
</section>
</div>

Passing props/state to/from parent component

So I have a parent component and a log in component.
I want the user to enter their details and then hit submit and then store/pass those details around so they can be used by other components.
how is this best done in React?
for example I have this input field inside my log in component
<p>
<input type="text" id="playerName" value={this.props.nameValue} onChange={this.props.handleNameChange}/>
</p>
Then I want to pass the value that is entered to the parent component
I have this function in my parent component:
handleNameChange(event){
this.setState({nameValue: event.target.value})
};
and in my return I have:
return (
<div>
<LoginPage handleClick={this.handleClick.bind(this)} handleNameChange={this.handleNameChange.bind(this)}/>
</div>
)
However, when I console.log(nameValue) I get undefined. any ideas? can add more code if necessary/relevant
From your example you never pass nameValue to the child component.
Updated your example of rendering the LoginPage, passing this.state.nameValue into the child component via props:
return (
<div>
<LoginPage
handleClick={this.handleClick.bind(this)}
handleNameChange={this.handleNameChange.bind(this)}
nameValue={this.state.nameValue}
/>
</div>
)
Your approach using state and props is fine. Are you sure that you shouldn't just be using...
console.log(this.state.nameValue);
This is a working example
class Parent extends React.Component {
constructor() {
super();
this.state = {
nameValue:''
};
}
render() {
return (
<Child handleClick={this.handleClick.bind(this)} handleNameChange={this.handleNameChange.bind(this)} nameValue={this.state.nameValue} />
);
}
handleNameChange(e) {
this.setState({
nameValue: e.target.value
});
}
handleClick() {
alert(this.state.nameValue);
}
}
class Child extends React.Component {
render() {
return (
<div>
<input type="text" value={this.props.nameValue} onChange={this.props.handleNameChange} />
<button onClick={this.props.handleClick}>Click Me!</button>
</div>
);
}
}
JSFiddle here.

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