I am trying to pass a custom component to a MUI Dialog in such way that it should open the Dialog itself and render its children.
const CustomDialog = ({children, someCustomComponent}) => {
const handleClickOpen = () => {
setOpen(true);
};
const handleClose = () => {
setOpen(false);
};
return(
<>
{someCustomComponent} // use this component to call handleOpen/handleClose
<Dialog>
<DialogTitle>
<DialogTItle>
<DialogContent>{children}</DialogContent>
<DialogActions>...</DialogActions>
</Dialog>
</>
);
}
CustomDialog.propTypes = {
someCustomComponent: PropTypes.node.isRequired,
}
And then call it like this
<CustomDialog someCustomComponent={<h1>open</h1>}>
{myDialogContent}
</CustomDialog>
Is this possible? So, essentially, I don't always want a button to open my Dialog. I want to have any component I pass to it to be able to open it.
This is kind of how this is done by using Button
return(
<>
<Button onClick={handleClickOpen} />
<Dialog>
...
but I want to pass any element to it.
Thanks!
A simple way to do it is with React.cloneElement
const CustomDialog = ({ children, someCustomComponent }) => {
const handleClickOpen = () => {
setOpen(true);
};
const handleClose = () => {
setOpen(false);
};
// clone the component and add the onClick handler
const customComponentClone = React.cloneElement(someCustomComponent, {
onClick: handleClickOpen
});
return (
<>
{customComponentClone}
<Dialog>
<DialogTitle>
<DialogTItle>
<DialogContent>{children}</DialogContent>
<DialogActions>...</DialogActions>
</Dialog>
</>
);
}
This way you can use it like you mentioned
<CustomDialog someCustomComponent={<h1>open</h1>}>
{myDialogContent}
</CustomDialog>
Check here a live version
I'm new to React, and I'm trying to render html with a function in React.
This is my code:
import React, { Component, useRef, useState, useEffect } from 'react';
import { render } from 'react-dom';
import Searc from './search'
const HandleSearch = () => {
const [name, searchName] = useState("")
const [comments, getComments] = useState([])
const nameForm = useRef(null)
const onSubmitSearch = async(e) => {
e.preventDefault();
try {
// do something
} catch (error) {
console.log(error.message);
}
}
const displayComment = async() => {
try {
const form = nameForm.current
console.log(form['name'].value)
const name = form['name'].value
const response = await fetch(`http://localhost:5000/folder/${name.toLowerCase()}`)
const jsonData = await response.json()
getComments(jsonData)
} catch (error) {
console.log(error.message)
}
}
useEffect(() => {
displayComment()
}, [])
return(
<div className="container">
<div className="form-group">
<h1 className="text-center mt-5">SEARCH MY LANDLORD</h1>
<form ref={nameForm} className="mt-5" onSubmit={onSubmitSearch}>
<Search name={'name'}/>
<div className="d-flex justify-content-center">
<button type="submit" className="d-flex btn btn-primary" onClick={displayComment}>Search</button>
</div>
</form>
<div>
<div>
{/*<tr>
<td>Mary</td>
</tr>*/}
{comments.map(comment => (
<tr>
<td>{comment.problem}</td>
</tr>
))}
</div>
</div>
</div>
</div>
)
}
export default HandleSearch;
The issue I have is that the full list of comments appears before I trigger the displayComments function (once it's trigger it works).
<div>
{/*<tr>
<td>Mary</td>
</tr>*/}
{comments.map(comment => (
<tr>
<td>{comment.problem}</td>
</tr>
))}
</div>
Is it possible to render the above html in the displayComments function so nothing appears before I actually specified which data to display?
You need to remove the useEffect if you want the state to only be set on the button click, because as of right now the state is being set with the useEffect() which is loading when your component is first rendered.
I am trying to build a calculator and want to print digits on the screen. I have not yet put the calculator algorithm, just only to print the digits on the screen.
const Keys = ({calcKeys})=>(<div className="display-keys">
<div className="screen"><handleClick></div>
{calcKeys.map((item)=>{
return <button className="display-keys">{item.key}</button>
})
}
class App extends React.Component { constructor(props) { super(props);
this.state={calcKeys:[{"key": "AC"},{"key": "CE"},{"key": "±"},{"key": "/"},{"key": "7"},{"key": "8"},{"key": "9"},{"key": "x"},{"key": "4"},{"key": "5"},{"key": "6"},{"key": "-"},{"key": "1"},{"key": "2"},{"key": "3"},{"key": "+"},{"key": "."},{"key": "0"}]};}
this.displayKeys = this.displayKeys.bind(this)];
const keyButton = document.querySelector('.display-keys');
handleClick() {
keyButton.addEventListener('click', (e) => {
return const keyPad = e.key;
});
}
render(){
return(
<div className="display-container">
<Keys calcKeys={this.state.calcKeys}/>
</div>
);
}
}
ReactDOM.render( <App />, document.getElementById("root"));
For this case, if you want to click on the button you don't need to add an addEventListener.
As you are using React, you can create a function to handle click.
If you want to handle a keypress on the keyboard, that's the case to use addEventListener.
I changed your code a bit in order to make it work as expected. I didn't add any logic to make the calculator work but clicking on any button will add it to state and display on "screen".
This is what I did:
// "Keys" Component receives the calcKeys and the handleClick function.
// It uses the handleClick function on the button onClick passing the current item key
const Keys = ({ calcKeys, handleClick }) => (
<div className="display-keys">
{calcKeys.map(item => (
<button onClick={() => handleClick(item.key)}>{item.key}</button>
))}
</div>
)
class App extends React.Component {
constructor(props) {
super(props);
this.state = {
calcKeys: [{"key": "AC"},{"key": "CE"},{"key": "±"},{"key": "/"},{"key": "7"},{"key": "8"},{"key": "9"},{"key": "x"},{"key": "4"},{"key": "5"},{"key": "6"},{"key": "-"},{"key": "1"},{"key": "2"},{"key": "3"},{"key": "+"},{"key": "."},{"key": "0"}],
value: '',
};
this.handleClick = this.handleClick.bind(this)
}
// Here I just receive the key and add it to state.
// This is the place to add logic, check if the key is "AC" for example and clean the state, etc.
handleClick(key) {
const { value } = this.state
this.setState({ value: `${value}${key}` })
}
render() {
const { value } = this.state
return (
<div className="display-container">
<div className="screen">{value}</div>
<Keys calcKeys={this.state.calcKeys} handleClick={this.handleClick} />
</div>
);
}
}
You can test it in a working JSFiddle here
I need to pass a html value as a parameter for my function like so:
<input type ="text" placeholder="Smart Contract Bytecode" name="name" id ="scbytecode"className="nice-textbox"/>
<button id="button" onClick={parseAddress("document.getElementById('smartcontract').value)"}>Submit!</button>
but Im getting an error:
TypeError: Cannot read property 'value' of null
here is the Full code.
Added this to give a better impression of whats going on cause the fixes below don't seem to fix it all. Any help is welcomed.
class App extends Component {
parseAddress(_smartcontract){
var contractObj = new ethweb3.eth.Contract(ERC20ABI, document.getElementById('smartcontract').value);
contractObj.getPastEvents(
'Transfer' || 'allEvents',
{
fromBlock: 0,
toBlock: 'latest'
},
function(err,res){
console.log(err,res);
//examples to access the data returned
console.log(res.length);
document.getElementById("totalAddresses").innerHTML = res.length;
document.getElementById("sampleAddress").innerHTML = res[0].returnValues.from;
document.getElementById("sampleAmount").innerHTML = res[0].returnValues.value;
}
);
}
deploSC = async () => {
const accounts = await goweb3.eth.getAccounts();
//const code = ethweb3.eth.getCode(document.getElementById('smartcontract').value); Not working
console.log(code);
goweb3.eth.sendTransaction({
from: accounts[0],
data: document.getElementById('scbytecode').value
}, function(error, hash){
console.log(error,hash);
});
}
render() {
return (
<div className="App">
<header className="App-header">
<p>
Enter the smart contract address:
<input type="text" name="name" id="smartcontract" className="nice-textbox"/>
<input type ="text" placeholder="Sc bytecode" name="name" id ="scbytecode"className="nice-textbox"/>
<button id="button" onClick={this.parseAddress}>Submit!</button>
<button onClick={this.deploSC}> Deploy Sc</button>
</p>
<p id="totalAddresses">0</p>
<p id="sampleAddress">0</p>
<p id="sampleAmount">0</p>
</header>
</div>
);
}
}
export default App;
There is a better way to do this in React using state and not directly accessing the DOM which should be avoided.
Store the value of an input in the component's state, then give it to the button's onClick event handler via this.state.inputVal.
class App extends React.Component {
constructor(props) {
super(props);
this.state = {
inputVal: ''
};
}
inputChanged = (e) => {
this.setState({ inputVal: e.target.value });
}
render() {
return (
<div>
<input type ="text" placeholder="Smart Contract Bytecode" name="name" id ="scbytecode" className="nice-textbox" onChange={this.inputChanged}/>
<button id="button" onClick={() => { console.log(this.state.inputVal); }}>Submit!</button>
</div>
);
}
}
// Render it
ReactDOM.render(
<App/>,
document.getElementById("react")
);
<div id="react"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
I think there is mismatch in id.
line 1 you gave "scbytecode"
line 2 you are trying access by id "smartcontract" which is not present, so you are seeing null
I have file upload input:
<input onChange={this.getFile} id="fileUpload" type="file" className="upload"/>
And I handle upload this way:
getFile(e) {
e.preventDefault();
let reader = new FileReader();
let file = e.target.files[0];
reader.onloadend = (theFile) => {
var data = {
blob: theFile.target.result, name: file.name,
visitorId: this.props.socketio.visitorId
};
console.log(this.props.socketio);
this.props.socketio.emit('file-upload', data);
};
reader.readAsDataURL(file);
}
If I upload same file twice, then upload event is not fired. How can I fix that? For simple js code it was enough to do the following: this.value = null; in change handler. How can I do it with ReactJS?
I think you can just clear the input value like this :
e.target.value = null;
File input cannot be controlled, there is no React specific way to do that.
Edit For old browsers (<IE11), you can use one of the following techniques.
See http://jsbin.com/zurudemuma/1/edit?js,output (tested on IE10 & 9)
What worked for me was setting a key attribute to the file input, then when I needed to reset it I update the key attribute value:
functionThatResetsTheFileInput() {
let randomString = Math.random().toString(36);
this.setState({
theInputKey: randomString
});
}
render() {
return(
<div>
<input type="file"
key={this.state.theInputKey || '' } />
<button onClick={this.functionThatResetsTheFileInput()} />
</div>
)
}
That forces React to render the input again from scratch.
This work for me - ref={ref => this.fileInput = ref}
<input id="file_input_file" type="file" onChange={(e) => this._handleFileChange(e)} ref={ref=> this.fileInput = ref} />
then in my case once the file was uploaded to the server , I clear it by using the statement below
this.fileInput.value = "";
I do it by updating key inside my file input.
This will force a re-render and previously selected file will go away.
<input type="file" key={this.state.inputKey} />
Changing the state inputKey will re-render the component.
One way to change the inputKey will be to always set it to Date.now() on click of a button which is supposed to clear the field.
With every click onClick you can reset the input, so that even with the same file onChange will be triggered.
<input onChange={this.onChange} onClick={e => (e.target.value = null)} type="file" />
import React, { useRef } from "react";
export default function App() {
const ref = useRef();
const reset = () => {
ref.current.value = "";
};
return (
<>
<input type="file" ref={ref} />
<button onClick={reset}>reset</button>
</>
);
}
The following worked for me using React Hooks. This is done using what is known as a "controlled input". That means, the inputs are controlled by state, or their source of truth is state.
TL;DR Resetting the file input was a two-step process using both the useState() and useRef() hooks.
NOTE: I also included how I reset a text input in case anyone else was curious.
function CreatePost({ user }) {
const [content, setContent] = React.useState("");
const [image, setImage] = React.useState(null); //See Supporting Documentation #1
const imageInputRef = React.useRef(); //See Supporting Documentation #2
function handleSubmit(event) {
event.preventDefault(); //Stop the pesky default reload function
setContent(""); //Resets the value of the first input - See #1
//////START of File Input Reset
imageInputRef.current.value = "";//Resets the file name of the file input - See #2
setImage(null); //Resets the value of the file input - See #1
//////END of File Input Reset
}
return (
<div>
<form onSubmit={handleSubmit}>
<input
type="text"
placeholder="Add Post Content"
onChange={event => setContent(event.target.value)}
value={content} //Make this input's value, controlled by state
/>
<input
type="file"
onChange={event => setImage(event.target.files[0])} //See Supporting Doc #3
ref={imageInputRef} //Apply the ref to the input, now it's controlled - See #2
/>
<button type="submit">Submit Form</button>
</form>
</div>
)
};
Supporting Documentation:
useState Hook
Returns a stateful value, and a function to update it.
useRef Hook
If you pass a ref object to React, React will set its current property to the corresponding DOM node whenever that node changes.
Using files from web apps
If the user selects just one file, it is then only necessary to consider the first file of the list.
You can also include this in your input element if you know you are not going to be using the built-in file input value at all.
<input value={""} ... />
This way the value is always reset to the empty string on render and you don't have to include it awkwardly in an onChange function.
I know file input is always uncontrolled however the following code still works in my own porject, I can reset the input with no problems at all.
constructor(props) {
super(props);
this.state = {
selectedFile: undefined,
selectedFileName: undefined,
imageSrc: undefined,
value: ''
};
this.handleChange = this.handleChange.bind(this);
this.removeImage = this.removeImage.bind(this);
}
handleChange(event) {
if (event.target.files[0]) {
this.setState({
selectedFile: event.target.files[0],
selectedFileName: event.target.files[0].name,
imageSrc: window.URL.createObjectURL(event.target.files[0]),
value: event.target.value,
});
}
}
// Call this function to reset input
removeImage() {
this.setState({
selectedFile: undefined,
selectedFileName: undefined,
imageSrc: undefined,
value: ''
})
}
render() {
return (
<input type="file" value={this.state.value} onChange={this.handleChange} />
);
}
We can reset file input by using key = {this.state.fileInputKey} and initialsing fileInputKey to Date.now() in constructor state.
On file upload success , we need to again assign fileInputKey: Date.now(), so it will have different value than previous and it create new file input component on next render()
We can also do this manually by clicking button to clear/reset file Input
Below is the working code :
import React from "react";
import { Button } from "reactstrap";
class FileUpload extends React.Component {
constructor(props) {
super(props);
this.state = {
selectedFile: null,
fileInputKey: Date.now(),
message: ""
};
this.handleClear = this.handleClear.bind(this);
this.onClickHandler = this.onClickHandler.bind(this);
this.onChangeHandler = this.onChangeHandler.bind(this);
}
onChangeHandler = event => {
this.setState({
selectedFile: event.target.files
});
};
onClickHandler = () => {
if (this.state.selectedFile === null) {
this.setState({
message: "Please select File"
});
return;
}
//axios POST req code to send file to server
{
/**
const data = new FormData()
data = this.state.selectedFile[0]
axios.post("http://localhost:8080/api/uploadFile/", data)
.then(res => {
if (res.status == 200) {
// upload success
}
})
.catch(err => {
//message upload failed
})
*/
}
//after upload to server processed
this.setState({
selectedFile: null,
fileInputKey: Date.now(),
message: "File Uploaded"
});
};
handleClear() {
this.setState({
selectedFile: null,
fileInputKey: Date.now(),
message: ""
});
}
render() {
return (
<div>
<input
type="file"
key={this.state.fileInputKey}
class="form-control"
onChange={this.onChangeHandler}
/>
<button
type="button"
class="btn btn-success btn-block"
onClick={this.onClickHandler}
>
Upload
</button>
<Button
type="button"
value="Clear"
data-test="clear"
onClick={this.handleClear}
>
{" "}
Clear{" "}
</Button>
<br />
<label>{this.state.message}</label>
</div>
);
}
}
export default FileUpload;
Here is my solution using redux form
class FileInput extends React.Component {
constructor() {
super();
this.deleteImage = this.deleteImage.bind(this);
}
deleteImage() {
// Just setting input ref value to null did not work well with redux form
// At the same time just calling on change with nothing didn't do the trick
// just using onChange does the change in redux form but if you try selecting
// the same image again it doesn't show in the preview cause the onChange of the
// input is not called since for the input the value is not changing
// but for redux form would be.
this.fileInput.value = null;
this.props.input.onChange();
}
render() {
const { input: { onChange, value }, accept, disabled, error } = this.props;
const { edited } = this.state;
return (
<div className="file-input-expanded">
{/* ref and on change are key properties here */}
<input
className="hidden"
type="file"
onChange={e => onChange(e.target.files[0])}
multiple={false}
accept={accept}
capture
ref={(input) => { this.fileInput = input; }}
disabled={disabled}
/>
{!value ?
{/* Add button */}
<Button
className="btn-link action"
type="button"
text="Add Image"
onPress={() => this.fileInput.click()}
disabled={disabled}
/>
:
<div className="file-input-container">
<div className="flex-row">
{/* Image preview */}
<img src={window.URL.createObjectURL(value)} alt="outbound MMS" />
<div className="flex-col mg-l-20">
{/* This button does de replacing */}
<Button
type="button"
className="btn-link mg-b-10"
text="Change Image"
onPress={() => this.fileInput.click()}
disabled={disabled}
/>
{/* This button is the one that does de deleting */}
<Button
type="button"
className="btn-link delete"
text="Delete Image"
onPress={this.deleteImage}
disabled={disabled}
/>
</div>
</div>
{error &&
<div className="error-message"> {error}</div>
}
</div>
}
</div>
);
}
}
FileInput.propTypes = {
input: object.isRequired,
accept: string,
disabled: bool,
error: string
};
FileInput.defaultProps = {
accept: '*',
};
export default FileInput;
In my case I had a functional component and after selecting a file it suppose to set the file name in the state so using any solution above was failing except the ref one which i fixed like this.
const fileUpload = props => {
const inputEl = useRef(null)
const onUpload = useCallback(e => {
uploadFile(fileDetails)
.then(res => {
inputEl.current.value = ''
})
.catch(err => {
inputEl.current.value = ''
})
})
return (
<input type='file' ref={inputEl} onChange={handleChange} />
<Button onClick={onUpload}>Upload</Button>
)
}
I recently got stumbled into this issue to reset the File type input field. I think it is still a milestone for most developers. So I thought I should share my solution.
Since we are listening to the onChange event to update the image file into some of our states, we will have our component rerendered once we set the state. In such case, we can specify the value of the input file as empty like value='' which will cause the input field to reset its value after each change of its value.
<input
type="file"
value=''
onChange={onChangeFnc}
/>