Getting the name property of the TextField (as a Select Box) Material-UI via the event object from t-CodePudding

I've been using the "@material-ui/core": "4.11.2" package with "react": "16.8.6". In the TextField component when the select prop is true, I can't get the name property of the TextField from the event object in handleFocus function.

<TextField
        id="standard-select-currency"
        name="mySelectBox"
        select
        label="Select"
        value={currency}
        onChange={handleChange}
        onFocus={handleFocus}
        helperText="Please select your currency"
      >
        {currencies.map((option) => (
          <MenuItem key={option.value} value={option.value}>
            {option.label}
          </MenuItem>
        ))}
</TextField>

Here is handleFocus and handleChange functions.

  const handleChange = (event) => {
    console.log(
      "event.target ==>",
      event.target,
      "event.target.name ==>", // mySelectBox
      event.target.name
    );
  };

  const handleFocus = (event) => {
    console.log(
      "event.target ==>",
      event.target,
      "event.target.name ==>", // undefined
      event.target.name
    );
  };

I create a complete example in this sandbox.

CodePudding user response：

I checked with some console logging and noticed that the name property is not an attribute of the event.target. The event.target you have logged displays

<div  tabindex="0" role="button" aria-haspopup="listbox" aria-labelledby="standard-select-currency-label standard-select-currency" id="standard-select-currency">$</div>

which has attributes class, tabindex, role, aria-haspopup, aria-labelledby, and id

but the sibling of your target which is accessed by event.target.nextSibling is

<input name="mySelectBox" aria-hidden="true" tabindex="-1"  aria-describedby="standard-select-currency-helper-text" value="USD"></input>

<input name="mySelectBox" aria-hidden="true" tabindex="-1"  aria-describedby="standard-select-currency-helper-text" value="EUR"></input>

depending on which currency you select has attributes name,aria-hidden,tabindex,class,aria-describedby and value

then you can access the name attribute inside the handleFocus as event.target.nextSibling.getAttribute('name') or event.target.nextSibling.name

codesandbox demo

CodePudding user response：

This is because the Texfield does not directly pass the onFocus to the input. From MUI,

The ref is forwarded to the root element.

Any other props supplied will be provided to the root element (FormControl).

the onFocus is passed to the FormControl element, which is a div, not an input as a result, doesn't have a name. You can use the NativeSelect or pass the onFocus property to the input props, which didnt play out very well when i tried in the Sandbox you provided.

The quickest solution for this is to pass a ref to the input, and on focus, get the name from the reference. This is how your code will look like then

export default function MultilineTextFields() {
  const [currency, setCurrency] = React.useState("EUR");
  const inputRef = React.useRef()

  const handleChange = (event) => {
    setCurrency(event.target.value);
    console.log(
      "event.target ==>",
      event.target,
      "event.target.name ==>",
      event.target.name
    );
  };

  const handleFocus = (event) => {
    console.log(
      "event.target ==>",
      inputRef,
      "event.target.name ==>",
      inputRef.current.node.name
    );
  };

  return (
    <form noValidate autoComplete="off">
      <TextField
      inputRef= {inputRef}
        id="standard-select-currency"
        name="mySelectBox"
        select
        label="Select"
        value={currency}
        onChange={handleChange}
        onFocus={handleFocus}
        helperText="Please select your currency"
      >
        {currencies.map((option) => (
          <MenuItem key={option.value} value={option.value}>
            {option.label}
          </MenuItem>
        ))}
      </TextField>
    </form>
  );
}

Here is the sandbox i used https://codesandbox.io/s/material-demo-forked-zjlz3?file=/demo.js