Develop Reference

Save Form values in ReactJS using checkboxes

I created a form component using react hook forms. The component is composed from a group of checkboxes and a text input. The text input appears when user click on the last checkbox custom. The idea of this one is: when the user will click on it appears a text input and the user can add a custom answer/option. Ex: if user type test within the input then when the user will save the form, there should appear in an array test value, but custom text should't be in the array. In my application i don't have access to const onSubmit = (data) => console.log(data, "submit");, so i need to change the values within Component component. Now when i click on submit i get in the final array the custom value. Question: how to fix the issue described above?
const ITEMS = [
{ id: "one", value: 1 },
{ id: "two", value: 2 },
{ id: "Custom Value", value: "custom" }
];
export default function App() {
const name = "group";
const methods = useForm();
const onSubmit = (data) => console.log(data, "submit");
return (
<div className="App">
<FormProvider {...methods}>
<form onSubmit={methods.handleSubmit(onSubmit)}>
<Component ITEMS={ITEMS} name={name} />
<input type="submit" />
</form>
</FormProvider>
</div>
);
}
export const Component = ({ name, ITEMS }) => {
const { control, getValues } = useFormContext();
const [state, setState] = useState(false);
const handleCheck = (val) => {
const { [name]: ids } = getValues();
const response = ids?.includes(val)
? ids?.filter((id) => id !== val)
: [...(ids ?? []), val];
return response;
};
return (
<Controller
name={name}
control={control}
render={({ field, formState }) => {
return (
<>
{ITEMS.map((item, index) => {
return (
<>
<label>
{item.id}
<input
type="checkbox"
name={`${name}[${index}]`}
onChange={(e) => {
field.onChange(handleCheck(e.target.value));
if (index === ITEMS.length - 1) {
setState(e.target.checked);
}
}}
value={item.value}
/>
</label>
{state && index === ITEMS.length - 1 && (
<input
{...control.register(`${name}[${index}]`)}
type="text"
/>
)}
</>
);
})}
</>
);
}}
/>
);
};
demo: https://codesandbox.io/s/winter-brook-sml0ww?file=/src/Component.js:151-1600

Assuming that the goal is to keep all the selections in the same group field, which must be an array that logs the selected values in provided order, with the custom input value as the last item if specified, perhaps ideally it would be easier to calculate the values in onSubmit before submitting.
But since the preference is not to add logic in onSubmit, maybe an alternative option could be hosting a local state, run the needed calculations when it changes, and call setValue manually to sync the calculated value to the group field.
Forked demo with modification: codesandbox
import "./styles.css";
import { Controller, useFormContext } from "react-hook-form";
import React, { useState, useEffect } from "react";
export const Component = ({ name, ITEMS }) => {
const { control, setValue } = useFormContext();
const [state, setState] = useState({});
useEffect(() => {
const { custom, ...items } = state;
const newItems = Object.entries(items).filter((item) => !!item[1]);
newItems.sort((a, b) => a[0] - b[0]);
const newValues = newItems.map((item) => item[1]);
if (custom) {
setValue(name, [...newValues, custom]);
return;
}
setValue(name, [...newValues]);
}, [name, state, setValue]);
const handleCheck = (val, idx) => {
setState((prev) =>
prev[idx] ? { ...prev, [idx]: null } : { ...prev, [idx]: val }
);
};
const handleCheckCustom = (checked) =>
setState((prev) =>
checked ? { ...prev, custom: "" } : { ...prev, custom: null }
);
const handleInputChange = (e) => {
setState((prev) => ({ ...prev, custom: e.target.value }));
};
return (
<Controller
name={name}
control={control}
render={({ field, formState }) => {
return (
<>
{ITEMS.map((item, index) => {
const isCustomField = index === ITEMS.length - 1;
return (
<React.Fragment key={index}>
<label>
{item.id}
<input
type="checkbox"
name={name}
onChange={(e) =>
isCustomField
? handleCheckCustom(e.target.checked)
: handleCheck(e.target.value, index)
}
value={item.value}
/>
</label>
{typeof state["custom"] === "string" && isCustomField && (
<input onChange={handleInputChange} type="text" />
)}
</React.Fragment>
);
})}
</>
);
}}
/>
);
};

Ok, so after a while I got the solution. I forked your sandbox and did little changes, check it out here: Save Form values in ReactJS using checkboxes
Basically, you should have an internal checkbox state and also don't register the input in the form, because this would add the input value to the end of the array no matter if that value is "".
Here is the code:
import "./styles.css";
import { Controller, useFormContext } from "react-hook-form";
import { useEffect, useState } from "react";
export const Component = ({ name, ITEMS }) => {
const { control, setValue } = useFormContext();
const [state, setState] = useState(false);
const [checkboxes, setCheckboxes] = useState(
ITEMS.filter(
(item, index) => index !== ITEMS.length - 1
).map(({ value }, index) => ({ value, checked: false }))
);
useEffect(() => {
setValue(name, []); //To initialize the array as empty
}, []);
const [inputValue, setInputValue] = useState("");
const handleChangeField = (val) => {
const newCheckboxes = checkboxes.map(({ value, checked }) =>
value == val ? { value, checked: !checked } : { value, checked }
);
setCheckboxes(newCheckboxes);
const response = newCheckboxes
.filter(({ checked }) => checked)
.map(({ value }) => value);
return state && !!inputValue ? [...response, inputValue] : response;
};
const handleChangeInput = (newInputValue) => {
const response = checkboxes
.filter(({ checked }) => checked)
.map(({ value }) => value);
if (state) if (!!newInputValue) return [...response, newInputValue];
return response;
};
return (
<Controller
name={name}
control={control}
render={({ field, formState }) => {
return (
<>
{ITEMS.map((item, index) => {
return (
<>
<label>
{item.id}
<input
type="checkbox"
name={`${name}[${index}]`}
onChange={(e) => {
if (index === ITEMS.length - 1) {
setState(e.target.checked);
return;
}
field.onChange(handleChangeField(e.target.value));
}}
value={item.value}
/>
</label>
{state && index === ITEMS.length - 1 && (
<input
value={inputValue}
onChange={(e) => {
setInputValue(e.target.value);
field.onChange(handleChangeInput(e.target.value));
}}
type="text"
/>
)}
</>
);
})}
</>
);
}}
/>
);
};

Incorrect validation when trying to send data from additional inputs

Hello everyone and thank you for reading this! Here is my problem that i can't solve:
My application has the following functionality:
There are 2 inputs, then a button, when clicked, 2 more inputs appear and a button to send data from all inputs to the console, however, in the additional field, one input is required. This is where my problem arises: now, if I called additional inputs and filled in all the data, they are transferred to the console, if I didn’t fill in the required field, an error message goes to the console, BUT. I also need, in the event that I did NOT call additional inputs, the data of 2 basic inputs was transferred to the console. At the moment I can't figure it out.
import React, { useState } from "react";
import ReactDOM from "react-dom/client";
import produce from "immer";
const FunctionalBlock = ({
id,
idx,
isDeleted,
toggleBlockState,
additionalValue,
additionalTitle,
setNewBlock,
index,
}) => {
return (
<div
style={{
display: "flex",
maxWidth: "300px",
justifyContent: "space-between",
}}
>
{!isDeleted ? (
<React.Fragment>
<strong>{idx}</strong>
<input
type="text"
value={additionalTitle}
onChange={(e) => {
const additionalTitle = e.target.value;
setNewBlock((currentForm) =>
produce(currentForm, (v) => {
v[index].additionalTitle = additionalTitle;
})
);
}}
/>
<input
type="text"
value={additionalValue}
onChange={(e) => {
const additionalValue = e.target.value;
setNewBlock((currentForm) =>
produce(currentForm, (v) => {
v[index].additionalValue = additionalValue;
})
);
}}
/>
<button onClick={toggleBlockState}>now delete me</button>
</React.Fragment>
) : (
<button onClick={toggleBlockState}>REVIVE BLOCK</button>
)}
</div>
);
};
const Application = () => {
const [newBlock, setNewBlock] = useState([]);
const [firstInput, setFirstInput] = useState("");
const [secondInput, setSecondInput] = useState("");
const getNewBlock = (idx) => ({
id: Date.now(),
idx,
isDeleted: false,
additionalValue: "",
additionalTitle: "",
});
const toggleIsDeletedById = (id, block) => {
if (id !== block.id) return block;
return {
...block,
isDeleted: !block.isDeleted,
};
};
const createOnClick = () => {
const block = getNewBlock(newBlock.length + 1);
setNewBlock([...newBlock, block]);
};
const toggleBlockStateById = (id) => {
setNewBlock(newBlock.map((block) => toggleIsDeletedById(id, block)));
};
const showInputData = () => {
newBlock.map((item) => {
if (item.additionalTitle.length < 3) {
console.log("it is less than 3");
} else if (!item.additionalTitle && !item.additionalValue) {
console.log(firstInput, secondInput);
} else {
console.log(
firstInput,
secondInput,
item.additionalTitle,
item.additionalValue
);
}
});
};
return (
<div>
<div>
<input
type="text"
value={firstInput}
onChange={(e) => {
setFirstInput(e.target.value);
}}
/>
<input
type="text"
value={secondInput}
onChange={(e) => {
setSecondInput(e.target.value);
}}
/>
</div>
<div>
<button onClick={createOnClick}>ADD NEW INPUTS</button>
</div>
<div>
{newBlock.map((block, index) => (
<FunctionalBlock
key={index}
{...block}
toggleBlockState={() => toggleBlockStateById(block.id)}
setNewBlock={setNewBlock}
index={index}
/>
))}
</div>
<button onClick={showInputData}>send data</button>
</div>
);
};
const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Application />);
Here is this code on sandbox for those who decided to help me. Thank you!
https://codesandbox.io/s/vigilant-booth-xnef6t

How to add input validation in react?

I am having a simple form that has firstName and lastName.
<label htmlFor="firstName">First Name: </label>
<input
type="text"
className="form-control"
id="firstName"
name="firstName"
value={basicDetails.firstName}
onChange={(event) => handleInputChange(event)}
/>
<label htmlFor="lastName">Last Name: </label>
<input
type="text"
className="form-control"
id="lastName"
name="lastName"
value={basicDetails.lastName}
onChange={(event) => handleInputChange(event)}
/>
For this I am trying to add validation.
The validation rules are,
Both fields should accept only text
First name is required and should have at least 4 characters.
If Last name field has value, then it needs to be at least 3 characters.
Things I have tried to achieve this,
components/utils.js
export function isLettersOnly(string) {
return /^[a-zA-Z]+$/.test(string);
}
components/basic_details.js
const handleInputChange = (event) => {
const { name, value } = event.target;
if (!isLettersOnly(value)) {
return;
}
setValue((prev) => {
const basicDetails = { ...prev.basicDetails, [name]: value };
return { ...prev, basicDetails };
});
};
On handle input field, I am making the validation to check whether the input has value but I am unable to get the point how to catch the actual validation error and display below respective input box.
Kindly please help me to display the validation message on the respective fields.
Working example:

I suggest adding an errors property to the form data in form_context:
const [formValue, setFormValue] = useState({
basicDetails: {
firstName: '',
lastName: '',
profileSummary: '',
errors: {},
},
...
});
Add the validation to basic_details subform:
const ErrorText = ({ children }) => (
<div style={{ color: 'red' }}>{children}</div>
);
const BasicDetails = () => {
const [value, setValue] = React.useContext(FormContext);
const { basicDetails } = value;
const handleInputChange = (event) => {
const { name, value } = event.target;
if (!isLettersOnly(value)) {
setValue((value) => ({
...value,
basicDetails: {
...value.basicDetails,
errors: {
...value.basicDetails.errors,
[name]: 'Can have only letters.',
},
},
}));
return;
}
switch (name) {
case 'firstName': {
const error = value.length < 4 ? 'Length must be at least 4.' : null;
setValue((value) => ({
...value,
basicDetails: {
...value.basicDetails,
errors: {
...value.basicDetails.errors,
[name]: error,
},
},
}));
break;
}
case 'lastName': {
const error = value.length < 3 ? 'Length must be at least 3.' : null;
setValue((value) => ({
...value,
basicDetails: {
...value.basicDetails,
errors: {
...value.basicDetails.errors,
[name]: error,
},
},
}));
break;
}
default:
// ignore
}
setValue((prev) => {
const basicDetails = { ...prev.basicDetails, [name]: value };
return { ...prev, basicDetails };
});
};
return (
<>
<br />
<br />
<div className="form-group col-sm-6">
<label htmlFor="firstName">First Name: </label>
<input
type="text"
className="form-control"
id="firstName"
name="firstName"
value={basicDetails.firstName}
onChange={(event) => handleInputChange(event)}
/>
</div>
<br />
{basicDetails.errors.firstName && (
<ErrorText>{basicDetails.errors.firstName}</ErrorText>
)}
<br />
<br />
<div className="form-group col-sm-4">
<label htmlFor="lastName">Last Name: </label>
<input
type="text"
className="form-control"
id="lastName"
name="lastName"
value={basicDetails.lastName}
onChange={(event) => handleInputChange(event)}
/>
</div>
<br />
{basicDetails.errors.lastName && (
<ErrorText>{basicDetails.errors.lastName}</ErrorText>
)}
<br />
</>
);
};
Lastly, check the field values and errors to set the disabled attribute on the next button in index.js. The first !(value.basicDetails.firstName && value.basicDetails.lastName) condition handles the initial/empty values state while the second condition handles the error values.
{currentPage === 1 && (
<>
<BasicDetails />
<button
disabled={
!(
value.basicDetails.firstName && value.basicDetails.lastName
) ||
Object.values(value.basicDetails.errors).filter(Boolean).length
}
onClick={next}
>
Next
</button>
</>
)}
This pattern can be repeated for the following steps.

First you must be getting converting controlled component to uncontrolled component error in your console. For controlled component it is always preferred to use state to set value for the input. And with onChange handler you set the state. I will try to put into a single component so you would get the idea and apply your case
import React, {useState} from 'react';
import {isLettersOnly} from './components/utils'; // not sure where it is in your folder structure
const MyInputComponent = ({value, ...props}) => {
const [inputValue, setInputValue] = useState(value || ''); // input value should be empty string or undefined. null will not be accepted.
const [error, setError] = useState(null);
const handleChange = event => {
const { name, value } = event.target;
if (!isLettersOnly(value)) {
setError('Invalid Input');
}
setInputValue(value);
}
return (
<>
<input
value={inputValue}
onChange={handleChange}
{...props}
/>
{error && (
<span className={"error"}>{error}</span>
)}
</>
)
}
export default MyInputComponent;
This is a very rudimentary component. just to show the concept. You can then import this component as your input field and pass necessary props like name, className etc from parent.
import React from 'react';
import MyInputComponent from 'components/MyInputComponent';
const MyForm = (props) => {
return props.data && props.data.map(data=> (
<MyInputComponent
name="lastName"
className="form-control"
value={data.lastName}
));
}

React : Cannot set property 'animation' of undefined

I have a list in React where I'm using .map to render a loop from an array of elements.
The radio inputs are working perfectly, everyone is independent of the others, but I can't do the same for Select.
The Select area is changing in every field, I want it to change to it specified field like I did for the options.
I tried to re-use the same handleChange that I used in the radios for it and instead I had this error.
Cannot set property 'animation' of undefined
In this line
newAnimations[indexurl].animation = name;
How do I manage to separate the selects ?
Note: This code is working fine, but it's updating the value on every field.
const onChange = (animations) => {
setAnimations(animations);
console.log(`Animation selected:`, animations);
};
Code :
https://codesandbox.io/s/dank-violet-jibzh?file=/src/App.js:1065-1194
import React, { useState } from "react";
import Select from "react-select";
export default () => {
const animationsList = [
{ value: "animation0", label: "Dance" },
{ value: "animation1", label: "Flip" },
{ value: "animation2", label: "Salsa" }
];
const reactList = [
{
id: "14444",
selected: "layout3",
animation: "animation1"
},
{
id: "24444",
selected: "layout3",
animation: "animation2"
},
{
id: "34444",
selected: "layout3",
animation: "animation1"
}
];
const [links, setLinks] = useState(reactList);
const [animations, setAnimations] = useState(animationsList[0]);
const handleChangeSelectedReact = (indexurl, layout) => {
const cloneLinks = [...links];
cloneLinks[indexurl].selected = layout;
setLinks(cloneLinks);
console.log(cloneLinks);
};
/* const onChange = (animations) => {
setAnimations(animations);
console.log(`Animation selected:`, animations);
};*/
const onChange = (indexurl, name) => {
const newAnimations = [...links];
newAnimations[indexurl].animation = name;
setAnimations(newAnimations);
console.log(newAnimations);
};
return (
<div>
<ul>
<div>
{links.map((url, indexurl) => (
<li key={url.id}>
<div>
<Select
options={animationsList}
onChange={onChange}
value={animations}
/>
<p />{" "}
<input
type="radio"
id={url.id}
name={url.id}
value="layout1"
checked={url.selected === "layout1"}
onChange={() =>
handleChangeSelectedReact(indexurl, "layout1")
}
/>
<label for="huey">Option 1</label>
</div>
<div>
<input
type="radio"
id={url.id}
name={url.id}
value="layout2"
checked={url.selected === "layout2"}
onChange={() =>
handleChangeSelectedReact(indexurl, "layout2")
}
/>
<label for="dewey">Option 2</label>
</div>
<div>
<input
type="radio"
id={url.id}
name={url.id}
value="layout3"
checked={url.selected === "layout3"}
onChange={() =>
handleChangeSelectedReact(indexurl, "layout3")
}
/>
<label for="louie">Option 3</label>
</div>
<br />
</li>
))}
</div>
</ul>
</div>
);
};

Multiple Selects share the same state, resulting in updates the value on every field. So we need to wrap Select into components and maintain their own state independently：
function SelectItem({ list }) {
const [value, setValue] = React.useState(list[0]);
const onChange = (newValue) => {
setValue(newValue);
};
return <Select options={list} onChange={onChange} value={value} />;
}
...
...
return (
<div>
{links.map((url, indexurl) => (
<SelectItem list={animationsList} />
))}
</div>
);
...
...
Update
Modify the links when select is selected:
function SelectItem(props) {
const [value, setValue] = React.useState(props.list[0]);
return (
<Select
options={props.list}
onChange={(newValue) => {
setValue(newValue);
props.onChange(newValue.value);
}}
value={value}
/>
);
}
...
...
const onChange = (index, animation) => {
const cloneLinks = [...links];
cloneLinks[index].animation = animation;
setLinks(cloneLinks);
console.log(cloneLinks);
};
return (
<div>
{links.map((url, indexurl) => (
<SelectItem
onChange={(animation) => onChange(indexurl, animation)}
list={animationsList}
/>
))}
</div>
);
...
...
Full code: https://codesandbox.io/s/happy-cloud-m6z99?file=/src/App.js:77-298

AutoComplete ReactJS / Redux NOT changing the search value

im trying to make the title of the movie clicked to be the in search input value.
exapmle: searched for "batman", clicked on result "batman ninja", search input becomes "batman ninja"
Search Component:
handleSelect is the function im passing to each search result
class MoviesSearch extends Component {
state = {
display: false,
title: ''
};
handleChange = e => {
this.props.movieSearch(e.target.value);
this.setState({
display: false
});
};
handleSubmit = e => {
e.preventDefault();
const { searchInput } = this.props;
this.props.fetchMovie(searchInput);
this.setState({
display: true
});
};
handleSelect = e => {
// this.setState({title: e.target.value})
// this.setState({title: e.target.value})
// this.setState({display: false, title: this.props.movies.Title})
// this.props.movieSearch(this.state.title)
}
render() {
//////////////////////////////////////////
////STATE:
const { movies } = this.props;
//////////////////////////////////////////
//// BUTTONS:
const btnDisabled = (
<button type="submit" disabled>
Search
</button>
);
const btnEnabled = <button type="submit">Search</button>;
///////////////////////////////////////////
//// DISPLAY CONTENT:
const display = (
<div className="dropdown-content">
<MovieList select={this.handleSelect}/>
</div>
);
///////////////////////////////////////////
console.log(this.state.title)
return (
<div className="movieSearch">
<form className="searchForm" onSubmit={this.handleSubmit}>
<div
className={movies.length === 0 ? "dropdown" : "dropdown is-active"}
>
<input
type="text"
placeholder="Enter Movie Name"
onChange={this.handleChange}
value={this.props.movies.Title}
/>
<div className="dropdown-menu">
{this.state.display ? display : null}
</div>
{this.props.searchInput.length <= 0 ? btnDisabled : btnEnabled}
</div>
</form>
</div>
);
}
}
const mapStateToProps = state => ({
searchInput: state.movies.searchInput,
movies: state.movies.movies
});
export default connect(mapStateToProps, { movieSearch, fetchMovie })(
MoviesSearch
);
MovieItem Component:
selectedItem is the function that was passed (handleSelect)
const MovieItem = ({ movie, selectedItem }) => {
return (
<NavLink className="dropdown-item" to="#" onClick={(e)=>selectedItem(e.movie.Title)}>
<img
className="poster"
src={movie.Poster === "N/A" ? "" : movie.Poster}
alt=""
/>
<span className="title">{movie.Title}</span>
</NavLink>
);
};
export default MovieItem;

In MovieItem component, use onClick={(e)=>selectedItem(movie.Title)}
In your parent component, use
handleSelect = value => {
this.setState({title: value})
}