Develop Reference

Typescript with React Hook Form and React-select Multiple selected value not submitted by the form

I am using react hook form and react select with typescript . Its works fine for single selected value. But when I choose isMulti for multiple selected value , I am unable to get the value from the submitted form .
Here is the code
interface ITopic {
value: string;
label: string;
}
...........
const topicOptions : ITopic[] = [
{ value: 'javascript', label: 'JAVASCRIPT' },
{ value: 'php', label: 'PHP' },
{ value: 'python', label: 'PYTHON' },
{ value: 'java', label:'JAVA' },
{ value: 'C#', label: 'C#' }
]
type TopicType = { label: string, value: string }
const [selectedTopic, setSelectedTopic] = useState<readonly ITopic[]>([]);
..........
<Controller
control={control}
render={({ field: { onChange, value, name, ref } }) =>{
const handleSelectionChange = (topicOptions: readonly SelectOptionType[]) => {
setSelectedTopic(topicOptions)
console.log(selectedTopic)
}
return (
<Select
isMulti
name={name}
value={selectedTopic}
options={topicOptions}
onChange={handleSelectionChange}
/>
)}}
name="topics"
/>
I am getting empty topics value. Need Help. Thank you.

First, if you are using react-hook-form to manage your form, you shouldn't in addition have useState for your variable.
What you want to do instead is to use onChange from the Controller's render method.
For instance, my multi select code is (assuming topicOptions is an array of TopicType: { label:string; value:string })
<Controller
control={control}
name="topics"
render={({ field: { onChange, value } }) => (
<Select
isMulti
name="topics"
options={topicOptions}
value={topicOptions.filter((el) => value?.includes(el.value))}
onChange={(option: TopicType[] | null) => {
if (option === null) {
onChange(null);
return;
}
onChange(option.map((el) => el.value));
}}
/>
)}
/>

React-Select if value exists show value if not show placeholder text

I'm using this component here: https://react-select.com/home
What I'm trying to accomplish is on page load if my array contains a value in my Assigned element then I want to display that by default in my react-select box if not then I want my placeholder Assign to to show.
Here is how my select looks:
<Select
value={this.state.Product[0].Assigned ? this.state.Product[0].Assigned : selectedAssigned}
onChange={this.handleChangeAssigned}
options={this.state.AssignedList}
placeholder={<div>Assign to:</div>}
/>
In my Product[0].Assigned there is currently a value, however the dropdown still has the placeholder Assign To. I tried changing value to value={this.state.Product[0].Assigned} but still no luck.
Here is my change handle:
handleChangeAssigned = selectedAssigned => {
this.setState(
{ selectedAssigned },
() => console.log(`Option selected:`, this.state.selectedAssigned)
);
};

It seems like you are storing the same data in multiple places. You are checking if you have an assignment by looking at this.state.Product[0].Assigned. But when you select an assignment you are not updating that property. Instead you are updating a completely separate property this.state.selectedAssigned. this.state.Product[0].Assigned never changes so if you see a placeholder at first then you will always see a placeholder.
The value that you set on the Select needs to be the same as the value that you update.
import React from "react";
import Select from "react-select";
interface Option {
label: string;
value: string;
}
interface State {
Product: any[];
AssignedList: Option[];
selectedAssigned: Option | null;
}
export default class MyComponent extends React.Component<{}, State> {
state: State = {
Product: [],
AssignedList: [
{ label: "a", value: "a" },
{ label: "b", value: "b" },
{ label: "c", value: "c" }
],
selectedAssigned: null
};
handleChangeAssigned = (selectedAssigned: Option | null) => {
this.setState({ selectedAssigned }, () =>
console.log(`Option selected:`, this.state.selectedAssigned)
);
};
render() {
return (
<Select
value={this.state.selectedAssigned}
onChange={this.handleChangeAssigned}
options={this.state.AssignedList}
placeholder={<div>Assign to:</div>}
/>
);
}
}
Code Sandbox Link

How to sync two dropdown lists with different display in React?

I have a list of countries, with key, value, text.
I would like to have two Dropdown (https://react.semantic-ui.com/modules/dropdown/) list, one shows the key, the other the text.
The goal is to allow to choose by key of by text (we can type in the dropdown); if I update one, the other is synchronized immediately.
How can I achieve this ?
<Dropdown
id='form-input-country'
label='Country'
placeholder='Select Country'
fluid
search
selection
options={countryISOOptions} // will show text
/>
<Dropdown
id='form-input-country'
label='Country'
placeholder='Select Country'
fluid
search
selection
options={countryISOOptions} // want to show key + want to sync in both direction
/>
I import countryISOOptions which looks like:
export const countryISOOptions = [
{key: 'AF', value: '4', text: 'Afghanistan'},
{key: 'AL', value: '8', text: 'Albania'},
{key: 'DZ', value: '12', text: 'Algeria'},
...

Maintain 2 option arrays. One for text and other for keys(derived from the first options array). Then maintain just one state and an onChange for both dropdowns and you will be fine.
See working copy of your code.
See code snippet:
import React, { useState } from "react";
import { Dropdown } from "semantic-ui-react";
import "./styles.css";
const countryISOOptions = [
{ key: "AF", value: "4", text: "Afghanistan" },
{ key: "AL", value: "8", text: "Albania" },
{ key: "DZ", value: "12", text: "Algeria" }
];
const countryKeys = countryISOOptions.map(({ key, value }) => ({
value,
text: key
}));
export default function App() {
const [text, setText] = useState("");
const onChangeTextDropdown = (e, d) => {
console.log("onChangeTextDropdown", e.target.value);
console.log("d", d);
setText(d.value);
};
return (
<div className="App">
<h1>Hello CodeSandbox</h1>
<Dropdown
id="form-input-countryz"
label="Country"
placeholder="Select Country - text"
value={text}
onChange={onChangeTextDropdown}
fluid
search
selection
options={countryISOOptions} // will show text
/>
<Dropdown
id="form-input-country"
label="Country"
placeholder="Select Country - key"
value={text}
onChange={onChangeTextDropdown}
fluid
search
selection
options={countryKeys} // want to show key + want to sync in both direction
/>
</div>
);
}

If you are using controlled version, then each Dropdown is a typical Inputthat supports two props called value and onChange. I'll use hook in the following example,
const [value1, setValue1] = setState('')
const [value2, setValue2] = setState('')
const onValue1Change = e => {
const value = e.target.value
setValue1(value)
if (value === 'key') setValue2('country')
}
return (
<div>
<Dropdown
value={value1}
onChange={onValue1Change}
...
/>
<Dropdown
value={value2}
...
/>
</div>
)

reset value when using react-select

I am using react-select for my select dropdown. The issue I am having is that there is no empty option to reset the dropdown value if the user changes their mind.
Currently I am taking the options and manually adding an empty string, but I feel there must be something already in the library to handle this? I cannot find anything in the docs.
My code looks like the below, and there is a code sandbox here.
import React from "react";
import Select from "react-select";
const App = () => {
const options = [
{ value: "chocolate", label: "Chocolate" },
{ value: "strawberry", label: "Strawberry" },
{ value: "vanilla", label: "Vanilla" }
];
return <Dropdown options={options} />;
}
const Dropdown = ({ options }) => {
const optionsWithEmptyOption = [{ value: "", label: "" }, ...options];
return <Select options={optionsWithEmptyOption} />;
};

Plase check this out
https://codesandbox.io/s/zow1c?module=/example.js
import React, { Component } from 'react';
import CreatableSelect from 'react-select/creatable';
import { colourOptions } from './docs/data';
export default class CreatableSingle extends Component<*, State> {
handleChange = (newValue: any, actionMeta: any) => {
console.group('Value Changed');
console.log(newValue);
console.log(`action: ${actionMeta.action}`);
console.groupEnd();
};
handleInputChange = (inputValue: any, actionMeta: any) => {
console.group('Input Changed');
console.log(inputValue);
console.log(`action: ${actionMeta.action}`);
console.groupEnd();
};
render() {
return (
<CreatableSelect
isClearable
onChange={this.handleChange}
onInputChange={this.handleInputChange}
options={colourOptions}
/>
);
}
}

Empty Unicode
I add line to options, and write between the apostrophes empty unicode like this: ⠀⠀⠀⠀⠀⠀⠀⠀ .. you can mark it but dont see it.
const options = [
{ value: "", label: "⠀" },
{ value: "chocolate", label: "Chocolate" },
{ value: "strawberry", label: "Strawberry" },
{ value: "vanilla", label: "Vanilla" }
];
And I change this:
return <Select options={options} />;

what about const optionsWithEmptyOption = [{ value: null, label: "Select..." }, ...options];
I'm not really good with explanations, but #NicoHaase is right, so here it goes...
as far as I know, you must give a value to value null (if nothing) or string ... same for the label, #1 because of the user UX and second so react-select knows what to display. But if you really need to leave it in black, and you can try to modify in the styles, in order to have the same height as the other options.

React - how to pass multiple input values to child in on change event when values have different types (is not always e.target.value)?

I have multiple input fields and 1 react-select dropdown field. I created a method in my parent component that sets the state with the values from the input, passes it down to the child which should call the method. My problem is that react-select doesn't take the value but an object like this:
{value: 'xy', name:'x', label: 'y'}
so normally my function in my onChange event handler would look like this (when passing multiple values):
in parent:
testing(e) {
this.setState({
[e.target.name]: e.target.value
})
}
in child:
<input type="text" name="maxfare" onChange={this.onChange}/>
...
onChange(e){
var value = [e.target.name] = e.target.value;
this.props.onChange(value);
}
...
However, while my input fields take:
e.target.value
my select dropdown takes entire 'e' - not e.target.value. I tried to pass my onChange function in child component 2 arguments, calling my method in parent with 2, but that doesn't to work. Any help would be great! My code is below (the relevant parts- if I forgot something that you think is important, please let me know). Ps. I thought about having 2 onChange functions, passing once my value for select dropdown and a second one doing the rest, but then I would need to pass 2 onChange methods to the child and I believe thats not possible in react?! Thanks!!:
Parent:
...
onChangeT(selectValue, value) {
this.setState({
origin: selectValue,
maxfare: value
...
})
}
render(){
....
<Parent cities={this.state.citiesToSelect} origin={this.state.origin} maxfare={this.state.maxfare} onChange={this.onChangeT}/>
...
}
Child:
....
onChangeC(e){
var value = [e.target.name] = e.target.value;
this.props.onChange(e, value);
console.log("name", name)
}
....
<Select
onChange={this.onChangeC}
labelKey='name'
value={this.props.origin}
options={this.props.cities}
/>
<input type="text" name="maxfare" onChange={this.onChangeC}/>

We want to be able to do this in the parent
onChange = (name, value) => {
this.setState({[name]: value});
}
We fix the "wiring" of the children onChange to do exactly that, raise an onChange with a name and a value. Wrap react-select and provide a consistent interface to the parent.
Form example
import * as React from 'react';
import Input from './Input';
import Select from './Select';
export default class Form extends React.Component {
state = {
input: '',
select: '',
options: ['A', 'B', 'C']
};
onChange = (name: string, value: string) => {
this.setState({[name]: value});
}
render() {
return (
<form>
<Input
label="Surname"
name={'input'}
value={this.state.input}
onChange={this.onChange}
/>
<Select
label="Grade"
name={'select'}
value={this.state.select}
options={this.state.options}
onChange={this.onChange}
/>
</form>
);
}
}
Input example
import * as React from 'react';
export default class Input extends React.Component {
onChange = (e) => {
const {onChange, name} = this.props;
if (onChange) {
onChange(name, e.currentTarget.value);
}
}
render() {
return (
<div>
<label>{this.props.label}</label>
<input
type="text"
name={this.props.name}
value={this.props.value}
onChange={this.onChange}
/>
</div>
);
}
}
And a DOM native <Select /> example
import * as React from 'react';
export default class Select extends React.Component {
onChange = (e) => {
const {onChange, name} = this.props;
if (onChange) {
onChange(name, e.currentTarget.value);
}
}
render() {
return (
<div>
<label>{this.props.label}</label>
<select
name={this.props.name}
value={this.props.value}
onChange={this.onChange}
>
{this.props.options.map(o => <option key={o}>{o}</option>)}
</select>
</div>
);
}
}

The fact that react-select doesn't return a native event nor a similar object shape of a native event, is forcing you to normalize the shape of the object that returned from it. You can do that by wrapping the Select component of react-select with your own component and returning a custom object for your use-case.
In this example we are trying to normalize the behavior of our onChange event both for inputs and Select. We will first check if the object that returned is having a target key, if it does we know that this is a native event that we are handling and we will set the state according to the name of the input and its value (exactly how you did it in your example).
If we don't have a target key, then we may handle a different kind of event.
We will check if we get a selectedValue key (just a convention between yourself, you can change the key as you like), then we will set the state by its name and selectedValue that we received.
This will only work if you will pass the name upwards of course.
So the object that you need to return from the custom Select component should look something like this:
{name: this.props.name, selectedValue }
// where selectedValue is the object received from the real Select component
Here is a running example:
const options = [
{ value: 'one', label: 'One' },
{ value: 'two', label: 'Two' },
]
const moreOptions = [
{ value: 'mike', label: 'johnson' },
{ value: 'lynda', label: 'bog' },
]
class MySelect extends React.Component {
handleChange = selectedValue => {
const { name, onChange } = this.props;
onChange({ name, selectedValue });
}
render() {
const { options, value, ...rest } = this.props;
return (
<Select
{...rest}
value={value}
onChange={this.handleChange}
options={options}
/>
);
}
}
class App extends React.Component {
constructor(props) {
super(props);
this.state = {
option1: '',
option2: '',
value1: 1,
value2: '',
value3: 3,
}
}
handleChange = e => {
let nextState;
if (e.target) {
const { name, value } = e.target;
nextState = { [name]: value };
} else if (e.selectedValue) {
const { name, selectedValue } = e;
nextState = { [name]: selectedValue };
}
this.setState(nextState);
}
render() {
const { value1, value2, value3, option1, option2 } = this.state;
return (
<div>
<MySelect
value={option1.value}
onChange={this.handleChange}
options={options}
name="option1"
/>
<div>
<span>input1 </span>
<input value={value1} name="value1" onChange={this.handleChange} />
</div>
<div>
<span>input2 </span>
<input value={value2} name="value2" onChange={this.handleChange} />
</div>
<div>
<span>input3 </span>
<input value={value3} name="value3" onChange={this.handleChange} />
</div>
<MySelect
value={option2.value}
onChange={this.handleChange}
options={moreOptions}
name="option2"
/>
</div>
);
}
}
ReactDOM.render(<App />, document.getElementById('root'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<script src="https://unpkg.com/prop-types#15.5.10/prop-types.js"></script>
<script src="https://unpkg.com/classnames#2.2.5/index.js"></script>
<script src="https://unpkg.com/react-input-autosize#2.0.0/dist/react-input-autosize.js"></script>
<script src="https://unpkg.com/react-select/dist/react-select.js"></script>
<link rel="stylesheet" href="https://unpkg.com/react-select/dist/react-select.css">
<div id="root"></div>