I have some code which dynamically adjusts a text field.
This version of the code works ok:
if (props.responsetxt === null) {
txtField = (
<TextField
autoFocus
margin="dense"
id="name"
label={emailField}
type="email"
fullWidth
onChange={e => emailFieldUpdate(e)}
/>
);
However I am using material-ui and I want to make use of their error option (https://material-ui.com/demos/text-fields/)
But if I modify my code as follows :
let errorFlag = null; // add this
txtField = (
<TextField
{errorFlag} // add this
autoFocus
margin="dense"
id="name"
label={emailField}
type="email"
fullWidth
onChange={e => emailFieldUpdate(e)}
/>
);
I get an error:
Parsing error: Unexpected token, expected "..."
Line 45: Parsing error: Unexpected token, expected "..."
43 | txtField = (
44 | <TextField
> 45 | {errorFlag}
| ^
46 | autoFocus
47 | margin="dense"
48 | id="name"
I do not understand why label and onChange dynamic parameters can work OK but the {errorFlag} substitution cannot ?
UPDATE
function DownloadForm(props) {
const intl = props.intl;
const boxTitle = intl.formatMessage({ id: 'downloadRequest.title' });
const cancelButton = intl.formatMessage({ id: 'button.cancel' });
const closeButton = intl.formatMessage({ id: 'button.close' });
const downloadButton = intl.formatMessage({ id: 'button.download' });
const emailField = intl.formatMessage({ id: 'downloadRequest.emailField' });
let boxText = null;
let waitingAnimation = null;
let returnArr = {};
let errorFlag = null;
const emailFieldUpdate = e => {
returnArr['email'] = e.target.value;
if (!EmailValidator(e.target.value)) {
console.log('setting true !');
errorFlag=true;
}
};
returnArr['subset'] = props.selectedSubset;
if (props.showWaitingAnimation) {
waitingAnimation = <CircularProgress />;
}
if (props.responsetxt === null) {
returnArr['correlID'] = UUIDGenerator();
returnArr['boxOpened'] = TAI64.now().toHexString();
boxText = intl.formatMessage({ id: 'downloadRequest.prompt' });
} else {
boxText = props.responsetxt;
}
let txtField, submitButton, closeText;
if (props.responsetxt === null) {
txtField = (
<TextField
error={errorFlag}
autoFocus
margin="dense"
id="name"
label={emailField}
type="email"
fullWidth
onChange={e => emailFieldUpdate(e)}
/>
);
submitButton = (
<Button
color="primary"
onClick={() =>
props.submit(returnArr, process.env.REACT_APP_ITS_AWS_SQS_DOWNLOAD)
}
>
{downloadButton}
</Button>
);
closeText = cancelButton;
} else {
closeText = closeButton;
}
return (
<div>
<Dialog open={props.open} aria-labelledby="form-dialog-title">
<DialogTitle id="form-dialog-title">{boxTitle}</DialogTitle>
<DialogContent>
<DialogContentText>{boxText}</DialogContentText>
{waitingAnimation}
{txtField}
</DialogContent>
<DialogActions>
<Button color="primary" onClick={props.close}>
{closeText}
</Button>
{submitButton}
</DialogActions>
</Dialog>
</div>
);
}
export default injectIntl(DownloadForm);
From the doc :
<TextField
error
id="standard-error"
label="Error"
defaultValue="Hello World"
className={classes.textField}
margin="normal"
/>
The error here is the short syntax of error={true} which is not possible to reproduce dynamically.
However, you can do the following :
<TextField
error={errorFlag}
autoFocus
margin="dense"
id="name"
label={emailField}
type="email"
fullWidth
onChange={e => emailFieldUpdate(e)}
/>
And as your error message is telling you, deconstructing a single attribute JSON may also work :
<TextField
...{error : errorFlag}
Renaming it to error will reduce the syntax even further :
<TextField
...{error}
EDIT :
You are using a stateless React component, which means that it is never going to re-render by itself, and calling emailFieldUpdate won't either. I refactored your component into a stateful one, where errorFlag is now in your state.
Calling this.setState({ errorFlag: true }) will update your flag and rerender your component, showing you the error. I also made few code readability changes :
import React, { Component } from 'react'
export default class DownloadForm extends Component {
constructor(props) {
super(props)
this.state = {
errorFlag: null,
returnArr: {}
}
}
emailFieldUpdate = e => {
this.setState({ returnArr:{ email: e.target.value }})
if (!EmailValidator(e.target.value)) {
console.log('setting true !');
this.setState({ errorFlag: true })
}
};
render() {
const { selectedSubset, responsetxt, showWaitingAnimation, intl, submit, open, close } = this.props //Decontructs your props
const { errorFlag, returnArr } = this.state //Deconstructs your state
const [boxTitle, cancelButton, closeButton, downloadButton, emailField] =
['downloadRequest.title', 'button.cancel', 'button.close', 'button.download', 'downloadRequest.emailField'].map(id =>
intl.formatMessage({ id })
);
let boxText = null;
let waitingAnimation = null;
returnArr['subset'] = selectedSubset;
if (showWaitingAnimation) {
waitingAnimation = <CircularProgress />;
}
if (!responsetxt) {
returnArr['correlID'] = UUIDGenerator();
returnArr['boxOpened'] = TAI64.now().toHexString();
boxText = intl.formatMessage({ id: 'downloadRequest.prompt' });
} else {
boxText = responsetxt;
}
return (
<div>
<Dialog open={open} aria-labelledby="form-dialog-title">
<DialogTitle id="form-dialog-title">{boxTitle}</DialogTitle>
<DialogContent>
<DialogContentText>{boxText}</DialogContentText>
{waitingAnimation}
{!responsetxt &&
<TextField
error={errorFlag}
autoFocus
margin="dense"
id="name"
label={emailField}
type="email"
fullWidth
onChange={this.emailFieldUpdate}
/>
}
</DialogContent>
<DialogActions>
<Button color="primary" onClick={close}>
{responsetxt ? closeButton : cancelButton}
</Button>
{!responsetxt &&
<Button
color="primary"
onClick={() => {submit(returnArr, process.env.REACT_APP_ITS_AWS_SQS_DOWNLOAD)}}>
{downloadButton}
</Button>
}
</DialogActions>
</Dialog>
</div>
);
}
}
You seem to be using React-intl, look at this documentation to make your messages directly into your JSX : https://github.com/yahoo/react-intl/wiki/Components#formattedmessage
Also I suggest reading conditional rendering in React and deconstruction in JS