How to set default value in material-UI select box in react? - reactjs

Question

I am using Select box from material-ui
I want to show "select the value" option by default selected but after that user is not able to select this option.
<FormControl required className={classes.formControl}>
<InputLabel htmlFor="circle">Circle</InputLabel>
<Select
value={circle}
onChange={event => handleInput(event, "circle")}
input={<Input name="circle" id="circle" />}
>
<MenuItem value="" disabled>
<em>select the value</em>
</MenuItem>
<MenuItem value={10}>Ten</MenuItem>
<MenuItem value={20}>Twenty</MenuItem>
<MenuItem value={30}>Thirty</MenuItem>
</Select>
<FormHelperText>Some important helper text</FormHelperText>
</FormControl>
Current code on sandbox: https://codesandbox.io/s/xoylmlj1qp
I want to make like this: https://jsfiddle.net/wc1mxdto/
Update
I changed the state 20 to blank string in circle
form: {
searchValue: "",
circle: '',
searchCriteria: ""
}
now expected output should be dropdown should show "please select value" but currently it showing this

Answer 1

You need to provide correct MenuItem value in state to be matched on render.
Here is the working codesandbox: Default Select Value Material-UI

Answer 2

You can just pass the displayEmpty into select
<Select
id="demo-simple-select-outlined"
displayEmpty
value={select}
onChange={handleChange}
>
and define the menuItem like
<MenuItem value=""><Put any default Value which you want to show></MenuItem>

Answer 3

As React introduced React-Hooks, you just need to pass your default value in React.useState() as React.useState(10).
export default function CustomizedSelects() {
const classes = useStyles();
const [age, setAge] = React.useState(10);// <--------------(Like this).
const handleChange = event => {
setAge(event.target.value);
};
return (
<form className={classes.root} autoComplete="off">
<FormControl className={classes.margin}>
<Select
value={age}
className={classes.inner}
onChange={handleChange}
input={<BootstrapInput name="currency" id="currency-customized-select" />}
>
<MenuItem value={10}>Ten</MenuItem>
<MenuItem value={20}>Twenty</MenuItem>
<MenuItem value={30}>Thirty</MenuItem>
</Select>
</FormControl>
</form>
);
}

Answer 4

<FormControl variant="outlined" className={classes.formControl}>
<InputLabel id="uni">UNI</InputLabel>
<Select
key={value}
defaultValue={value}
labelId="uni"
id="uni"
name="uni"
onBlur={onChange}
label="uni"
>
{unis.map((u, i) => (
<MenuItem value={u.value} key={i}>
{u.label}
</MenuItem>
))}
</Select>
</FormControl>;

Answer 5

Just use the defaultValue attribute of select.
You can refer to the Material UI Select API Docs to know more.
import React from 'react';
import {useState} from 'react';
import FormControl from '#material-ui/core/FormControl';
import InputLabel from '#material-ui/core/InputLabel';
import Select from '#material-ui/core/Select';
import MenuItem from '#material-ui/core/MenuItem';
const Selector = () => {
const [Value, setValue] = useState("1"); // "1" is the default value in this scenario. Replace it with the default value that suits your needs.
const handleValueChange = event => {
setValue(event.target.value);
}
return(
<FormControl>
<InputLabel id="Input label">Select</InputLabel>
<Select
labelId= "Input label"
id= "Select"
value= {Value}
defaultValue= {Value}
onChange= {handleValueChange}
>
<MenuItem value="1">Item1</MenuItem>
<MenuItem value="2">Item2</MenuItem>
<MenuItem value="3">Item3</MenuItem>
</Select>
</FormControl>
)
};
export default Selector;

Answer 6

If you take a look at the Select Api of Material UI here, you could do it easily.
As explained above, you need to pass the default value in your state variable:
const [age, setAge] = React.useState(10);// <--------------(Like this).
Set displayEmpty to true:
If true, a value is displayed even if no items are selected.
In order to display a meaningful value, a function should be passed to the renderValue prop which returns the value to be displayed when no items are selected. You can only use it when the native prop is false (default).
<Select
displayEmpty
/>

Answer 7

I had a similar issue. In my case, I applied a function directly to onChange so I had something like this:
export default function CustomizedSelects() {
const classes = useStyles();
const [age, setAge] = React.useState(10);
return (
<form className={classes.root} autoComplete="off">
<FormControl className={classes.margin}>
<Select
value={age}
className={classes.inner}
onChange={(event) => setAge(event.target.value)}
input={<BootstrapInput name="currency" id="currency-customized-select" />}
>
<MenuItem value={10}>Ten</MenuItem>
<MenuItem value={20}>Twenty</MenuItem>
<MenuItem value={30}>Thirty</MenuItem>
</Select>
</FormControl>
</form>
);
}
I also had a separate button to clear select value (or select the default empty value). All was working, the select value was set correctly, except the Select component did not animate to its default form - when no value is selected. I fixed the problem by moving onChange to a handleChange separate function as it is in the code example #B4BIPIN is presenting.
I am not an expert in React and still learning and this was a good lesson. I hope this helps ;-)

Answer 8

Take a list of objects you want to display in the Select dropdown and initialise it using useState. Use the state now to show the value and update the state on the change of the dropdown.
const ackList = [
{
key: 0,
value: "Not acknowledged",
},
{
key: 1,
value: "Acknowledged",
},
];
function AcknowledgementList() {
//state to initialise the first from the list
const [acknowledge, setAcknowledge] = useState(ackList[1]);
//update the state's value on change
const handleChange2 = (event) => {
setAcknowledge(ackList[event.target.value]);
};
return (
<TextField
select
fullWidth
value={acknowledge.key}
onChange={handleChange2}
variant="outlined"
>
{ackList.map((ack) => (
<MenuItem key={ack.key} value={ack.key}>
{ack.value}
</MenuItem>
))}
</TextField>
);
}

Answer 9

The problem here is all to do with some pretty poor coding on the part of the MUI folks, where on several components, they have magic strings and really are doing silly things.
Let's take a look at the state here:
const [age, setAge] = React.useState('3');
You can see that we are having to specify the VALUE as a string. Indeed the data type that the Select control takes is a string | undefined. So the fact we are having to use a number value as a string is the source of confusion.
So how does that work?
It is all to do with the MenuItem component. Let's take a look:
<MenuItem value={1}>First Choice</MenuItem>
<MenuItem value={2}>Second Choice</MenuItem>
<MenuItem value={3}>Third Choice</MenuItem>
You can see that we are indeed having to specify the VALUE of the MenuItem as a number.
So in this case, specifying '3' as the State value, as a string, will select the Third Choice on load.
You can set the VALUE in the Select control as the state value.
Don't forget, when handling the onChange event, that you will need to convert the event.target.value to string.