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

Add to favourites and view from favourites with React Hooks?

I have a state
const [ideas, setIdeas] = useState([{title:"test", favourite:false]);
Component Idea.jsx returns props.title and a button "fav".
App.jsx maps through the idea[] and renders each idea.title in
<Item title = {idea.title}/>
on the page.
Problem:
Every time when "fav" is clicked I want to toggle ideas[index].favourite.
How to change a value of favourite only for an idea that was clicked?
How to add this exact idea to the array favourites[]?
App.jsx
function App() {
const [ideas, setIdeas] = useState([{title:"test",
favourite:false}]);
const [isClicked, setIsClicked] = useState(false)
function showAllIdeas () {
setIsClicked(prevValue => {
return !prevValue
}
)
}
function mapIdeas(){return ideas.map((ideaItem, index) => {
return (<Idea
key = {index}
id = {index}
title = {ideaItem.title}
/>
);
})}
return ( <div>
<Fab color="primary" onClick={showAllIdeas}>{expandText()}</Fab>
{isClicked && mapIdeas()}
</div>)
}
Item.jsx
function Idea(props) {
const [isClicked, setIsClicked] = useState(false)
function handleClick(){
setIsClicked(prevValue => {
return !prevValue
})
}
console.log(isClicked)
return(
<div className={"idea-list" } ><p>{props.title} {isClicked ?
<StarIcon onClick={handleClick}/> :<StarBorderIcon onClick=.
{handleClick}/>}</p>
</div>
)
}

const handleFavToggle = (index) => {
setItems(items=> {
const data = [...items]
data[index] = {...data[index],favourite: !data[index].favourite }
return data
})
}
<Item key={index} title={item.title} index={index} handleFavToggle={handleFavToggle}/>
In item component you have to handle click with handleFavToggle and pass all params

Loop in React JSX

Instead of using fileList.map(), I want to put it in for loop and setTimeout(500) for every single loop. How can I do it ?
const SortableList = SortableContainer(({ fileList }) => (
<div>
{
fileList.map((file, index) => (
<SortableItem key={`item-${index}`} index={index} value={file} />
))
}
</div>
))

A very simple way is to create a new array which should contain the items which are currently visible.
Then do a simple setTimeout which will call a recursive function every 500ms that will add one element to the visible array.
const SortableList = SortableContainer(({ fileList }) => {
const [visibleItems, setVisibleItems] = useState([]);
useEffect(() => {
function displayNext(next) {
setVisibleItems(prevItems => [...prevItems, fileList[next]]);
if (++next < fileList.length) {
setTimeout(() => {
displayNext(next);
}, 500);
}
}
displayNext(0);
}, []);
return (
<div>
{
visibleItems.map((file, index) => (
<SortableItem key={`item-${index}`} index={index} value={file} />
))
}
</div>
)});
Let me know if works!

You can do something like this:
import React, {useState, useEffect} from 'react';
const ITEMS_TO_ADD_IN_EACH_TIMEOUT = 50
const SortableList = SortableContainer(({ fileList }) => {
const [visibleItems, setVisibleItems] = useState([])
useEffect(() => {
const timer = setTimeout(() => {
setVisibleItems([fileList.slice(0, visibleItems.length + ITEMS_TO_ADD_IN_EACH_TIMEOUT)])
}, 500);
return () => clearTimeout(timer);
})
return (
<div>
{
visibleItems.map((file, index) => (
<SortableItem key={`item-${index}`} index={index} value={file} />
))
}
</div>
))
}

update is not capturing and unable to update the input field

please find below code which contains name id and am rendering initially using map
am replacing id value to input type in UI
with the updated input type am trying to update the value onchange
update is not capturing and unable to update the input field
any suggestion?
please refer below snippet
import React, { useState } from "react";
const CstmInput = (props) => {
return (
<input
name={props.name}
type="text"
value={props.value}
onChange={(event) => props.onInputChange(event)}
/>
);
};
export default CstmInput;
import React, { useState } from "react";
import CstmInput from "./CstmInput";
const HierarcyTest = () => {
let rowData = [
{ name: "first", id: 10 },
{ name: "second", id: 20 },
];
const [data, setData] = useState(rowData);
const [name, setName] = useState({ fn: "test" });
const onInputChange = (e) => {
console.log("---event---", e.target.value);
setName({ ...name, fn: e.target.value });
};
let updateValue = () => {
let newData = data.map(
(item, index) =>
(item.id = (
<CstmInput name={item.name} value={item.id} onInputChange={(e) => onInputChange(e)} />
))
);
setData([...data, newData]);
};
return (
<div>
<div>Testing</div>
{data.map((val) => (
<h6>
{" "}
{val.name} {val.id}
</h6>
))}
<button onClick={updateValue}> Click </button>
</div>
);
};
export default HierarcyTest;

A few things why your code isn't working as intended:
1.
let updateValue = () => {
let newData = data.map((item, index) => {
if (item.id === 10) {
return [
(item.id = (
<CstmInput
value={item.id}
onInputChange={(e) => onInputChange(e)}
/>
)),
];
}
});
setData([...data, newData]);
};
In the above function inside the callback of map, you're only returning when a condition satisfies. Are you trying to filter the array instead? If not then return something when the if condition fails.
And why are you returning an array?
return [
(item.id = (
<CstmInput
value={item.id}
onInputChange={(e) => onInputChange(e)}
/>
)),
];
the above code seems logically wrong.
2.
const onInputChange = (e) => {
console.log("---event---", e.target.value);
setName({ ...name, fn: e.target.value });
};
If you want to update state which depends on the previous state then this is how you do it:
setName((prevState) => ({ ...prevState, fn: e.target.value }));
but since you're not actually relying on the properties of the previous state you can just use:
setName({fn: e.target.value });
Note that since your state only has one property and you want to update that single property you can completely overwrite the state, you don't need to spread the previous state.
update
change the updateValue function as the following:
let updateValue = () => {
setData(prevData => {
return prevData.map(el => {
return { ...el, id: <CstmInput value={el.id} onInputChange={(e) => onInputChange(e)} /> };
})
});
};
A stackblitz example I've created that implements what you're trying to do.