How to pass state props to another component - reactjs

I want to pass a state variable to another component but i don't get it what i'm doing wrong.
I have a component for radio inputs and I need to pass that taskLabel to Form component.
path is components/inputs/index.js
const TaskLabel = (props) => {
const [taskLabel, setTaskLabel] = useState('');
return (
<div label={props.taskLabel} >
<input
type='radio'
name='label'
value='urgent'
onChange={(e) => setTaskLabel(e.target.value)}
/>
<input
type='radio'
name='label'
value='not-urgent'
onChange={(e) => setTaskLabel(e.target.value)}
/>
</div>
);
};
i want to receive the taskLabel value, to use it in submitHandler function.
components/form/index.js
const Form = ({taskLabel}) => {
return (
<form onSubmit={submitHandler}>
<input
type='text'
placeholder='Text here'
className='form-input'
value={task}
onChange={(e) => {
setTask(e.target.value);
}}
/>
<TaskLabel taskLabel={taskLabel} />
</form>
)
}
This is what i tried, to pass taskLabel props from label={taskLabel}.

You need to move your state, to Form component, like this:
const [labelProp, setLabelProp] = useState("");
Your TaskLabel component should be
<TaskLabel label={{ labelProp, setLabelProp }} />
That means, you send label, as a prop to TaskLabel component.
In TaskLabel component you need to recive the prosp, by passing to component {label}.
Next, for every input use onChange={(e) => label.setLabelProp(e.target.value)}.
Edited sandbox => https://codesandbox.io/s/laughing-proskuriakova-dhi568?file=/src/components/task-label/index.js

Generally speaking, the concept is "data-down, actions-up". So if you want to pass data down to a lower-level component, you just pass a prop. If you want to update a value from a lower-level component to a higher-level component, you could pass a setter function down as a prop and call that.
Note I just call it taskLevelProp for a little more clarity. You should probably use a better name.
TaskLabel (lower level component)
/* It looks like TaskLabelProp gets passed in from something else.
Otherwise, you would use useState to get your setter function */
const TaskLabel = ({taskLabelProp, setTaskLabelProp}) => {
return (
<div label={props.taskLabel} >
<input
type='radio'
name='label'
value='urgent'
onChange={(e) => setTaskLabelProp(e.target.value)}
/>
<input
type='radio'
name='label'
value='not-urgent'
onChange={(e) => setTaskLabelProp(e.target.value)}
/>
</div>
);
};
Form (higher level component)
const Form = () => {
const [taskLabelProp, setTaskLabelProp] = useState('');
return (
<form onSubmit={submitHandler}>
<input
type='text'
placeholder='Text here'
className='form-input'
value={task}
onChange={(e) => {
setTask(e.target.value);
}}
/>
<TaskLabel taskLabel={taskLabelProp, setTaskLabelProp} />
</form>
)
}
Let me know if this answers your question.
EDIT: Made Form use useState. Based off your code, I was assuming you were using useState at the app level.

function App() {
const [task, setTask] = useState("");
const [taskLabelProp, setTaskLabelProp] = useState("");
const handleChange = (e) => {
setTaskLabelProp(e.target.value);
};
const submitHandler = (e) => {
e.preventDefault();
};
return (
<div className="App">
<form onSubmit={submitHandler}>
<input
type="text"
placeholder="Text here"
className="form-input"
value={task}
onChange={(e) => {
setTask(e.target.value);
}}
/>
<TaskLabel
onChange={handleChange}
taskLabelProp={taskLabelProp}
taskLabel="select"
/>
<button type="submit">fs</button>
</form>
</div>
);
}
export default App;
const TaskLabel = ({ taskLabel, onChange, taskLabelProp }) => {
return (
<div label={taskLabel}>
<input
type="radio"
name="label"
value="urgent"
onChange={(e) => onChange(e)}
checked={taskLabelProp === "urgent"}
/>
urgent
<input
type="radio"
name="label"
value="not-urgent"
onChange={(e) => onChange(e)}
checked={taskLabelProp === "not-urgent"}
/>
not-urgent
</div>
);
};
export default TaskLabel;

Related

Data is delayed by one while passing from child component to parent

i have two component App and Child .And whenever there's a change in the input field of the Child component it should update the change in the App component instantly.
But rather than updating the App instantly it is one step behind.
here is the code :-
App component
function App() {
const [ChildData, setChildData] = useState("");
return (
<div>
<div>
<Child passdata={setChldData}/>
</div>
<div>
{ChildData.name}
</div>
</div>
)
}
Child component
function Child(props) {
const [Data, setData] = useState({ name:'' ,title:'' ,phone:'' });
const handleChange = (e)=>{
setData({...Data, [e.target.name] : e.target.value})
props.passdata(Data)
}
return (
<div>
<h2>Child Data</h2>
<input type="text" name='name' onChange={handleChange} placeholder={"Name"}/>
<input type="text" name='title' onChange={handleChange} placeholder={"Title"}/>
<input type="number" name='phone' onChange={handleChange} placeholder={"Phone number"}/>
</div>
)
}
Whenever there;s a change in the input field it is one step behind.
i want the App component change simultaneously with the input from Child
function Child(props) {
const [Data, setData] = useState({ name:'' ,title:'' ,phone:'' });
const handleChange = (e)=>{
setData((prevData) => {
const newData = {...prevData, [e.target.name] : e.target.value}
props.passData(newData)
return newData
})
}
return (
<div>
<h2>Child Data</h2>
<input type="text" name='name' value={data.name} onChange={handleChange} placeholder={"Name"}/>
<input type="text" name='title' value={data.title} onChange={handleChange} placeholder={"Title"}/>
<input type="number" name='phone' value={data.phone} onChange={handleChange} placeholder={"Phone number"}/>
</div>
)
}
By the way you also forgot to bind value on the fields so changes in the state from somewhere other than typing in the box wouldn't have been reflected. I've fixed that too.
Additionally what you are doing looks like a code smell. You generally don't want to duplicate state in two places. Instead, you should have one canonical truth. What is the point in the copy that exists in child if you can just pass it back down from the parent?

React - pass props into input component

What I need is to be able to customize textAreaCount and other props in each separate instance of <Texarea/>. The textAreaCount is different for each <Texarea/> so how do I modify the component to be able to pass in custom textAreaCount for each <Texarea/>?
https://codesandbox.io/s/rkv88-forked-vjo0rn?file=/src/App.js:0-948
import React, { useState } from "react";
const Textarea = (value, id, maxLength, textAreaLimit) => {
const [textAreaCount, ChangeTextAreaCount] = React.useState(0);
const [state, setstate] = useState({
headline: "",
title: ""
});
const { headline, title } = state;
const changevalue = (e) => {
setstate({
...state,
[e.target.name]: value
});
ChangeTextAreaCount(e.target.value.length);
};
return (
<>
<p>{textAreaCount}/{textAreaLimit}</p>
<textarea
type="text"
rows={5}
id={id}
value={value}
maxLength={maxLength}
onChange={(e) => {
changevalue(e);
}}
/>
</>
);
};
export default function FullWidthTabs() {
return (
<div>
<Textarea value={headline} id="test" maxLength={5} textAreaLimit={5}/>
<Textarea value={title} id="test2" maxLength={10} textAreaLimit={10}/>
</div>
);
}
Forward the props you need.
const Textarea = (props) => {
const [textAreaCount, setTextAreaCount] = React.useState(0);
const recalculate = (e) => {
setTextAreaCount(e.target.value.length);
};
return (
<>
<p>{textAreaCount}/5</p>
<textarea type="text" rows={5} maxLength={5} onChange={recalculate} {...props} />
</>
);
};
Now it will forward any props into the textarea element. This will set the id and will overwrite the rows prop.
<Textarea id="textarea-1" rows={4} />
<Textarea id="textarea-2" rows={5} maxLength={10} />
As we can see you try to pass props as below:
<Textarea value={title} id="test2" maxLength={10} textAreaLimit={10}/>
But In Your Textarea Component you received props argument as multiple args as below:
const Textarea = (value, id, maxLength, textAreaLimit) => {
return (
<>
</>
);
};
Instead that you need to destruct your props argument or you can set whole passed value props as single object props as below:
Method 1:
const Textarea = ({value, id, maxLength, textAreaLimit}) => {
return (
<>
<textarea type="text" id={id} value={value} rows={5} maxLength={maxLength} onChange={recalculate} textAreaLimit={textAreaLimit} />
</>
);
};
Method 2:
const Textarea = ({...props}) => {
return (
<>
<textarea type="text" id={id} value={value} rows={5} maxLength={maxLength} onChange={recalculate} textAreaLimit={textAreaLimit} />
</>
);
};
Method 3:
const Textarea = (props) => {
return (
<>
<textarea type="text" id={props.id} value={props.value} rows={5} maxLength={props.maxLength} onChange={recalculate} textAreaLimit={props.textAreaLimit} />
// Or Instead you can do as below
// <textarea type="text" rows={5} maxLength={5} onChange={recalculate} {...props} />
</>
);
};

How to validate a child's component data from the parent without useEffect on each input

I have a reactjs component called payment that has and addressForm child componenet.
Now in my payment I have a next button that user needs to press to move to the next step but before moving the parent needs to validate the addressFrom's data.
Payment (PARENT)
<div ref={sliderRef} className='slider'>
<AddressForm
callback={(data) => registerAddress(data)}
setCanGoNext={val => setCanGoNext(val)}/>
<Paymentform/>
<InformationalForm/>
</div>
AddressForm (CHILD)
<div className="input-container-parent">
<div className="input-container-left">
<Input label="Country" value={country} setValue={e => setCountry(e)}/>
<Input label="County" value={county} setValue={e => setCounty(e)}/>
<Input label="City" value={city} setValue={e => setCity(e)}/>
<Input label="Street name and number" value={streetAndNumber} setValue={e => setStreetAndNumber(e)}/>
<Input label="Zipcode" value={zipcode} setValue={e => setZipcode(e)}/>
</div>
<div className="input-container-right">
<Input label="Person of contact" value={person} setValue={e => setPerson(e)}/>
<Input label="Phone number with contry prefix" value={phone} setValue={e => setPhone(e)}/>
<Input label="Email address" value={email} setValue={e => setEmail(e)}/>
<Input label="Adittional info" value={additionalInfo} setValue={e => setAdditionalInfo(e)}/>
<Input label="Note" value={note} setValue={e => setNote(e)}/>
</div>
<div>
Now my question is: can I validate somehow this data from the parent ONLY on click of the button 'next'. So I don't have to useEffect in child with all the child's properties to check if the form is valid or not
I have created sample email validation below. We will call child's method(which will be validating the email) from the parent upon clicking the next button. I am using react hooks in the below example.
Parent Component
import { Child } from "./Child";
import { useRef } from "react";
export default function Parent() {
const childRef = useRef();
const validateChildProperties = () => {
console.log(childRef.current.validateEmail()); // consoles whether the email is valid or not
};
return (
<>
<Child ref={childRef} />
<button onClick={() => validateChildProperties()}>Next</button>
</>
);
}
Child Component
import React, { useState, forwardRef, useImperativeHandle } from "react";
export const Child = forwardRef((props, ref) => {
const [email, setEmail] = useState("");
useImperativeHandle(ref, () => ({
validateEmail() {
return isValidData();
}
}));
const isValidData = () => {
const regex = /^((?!\.)[\w\-_.]*[^.])(#\w+)(\.\w+(\.\w+)?[^.\W])$/;
return regex.test(email);
};
return (
<>
<input
type="text"
onChange={(e) => setEmail(e.target.value)}
placeholder="enter your email"
/>
<span>Email is {email}</span>
</>
);
});
Please find the below link which is having examples of both functional component and class component.
https://codesandbox.io/s/stackoverflow-6u05e7?file=/src/Validation/Parent.js

how to get the data from a component within a form in react

I have a with the following structure in react...
<form>
<div>
<label>Name</label>
<input />
</div>
<div>
<label>Age</label>
<input />
</div>
<div>
<label>Gender</label>
<input />
</div>
<AddressComponent />
<button type='submit'>
Submit
</button>
</form>
Does anyone know if there is a way for me to pass the AddressComponent data up to the parent form component onSubmit? The AddressComponent has a lot of state to manage and a load of functions and it appears a few more times across my website and so I don't want to keep repeating the same code over and over again.
Anyone know if there's a way for me to pass the AddressComponent state up to the parent form component onSubmit?
you can use ref to get access to the child functions so:
const AddressComponent = ({}, ref) => {
const [data, setData] = useState();
useImperativeHandle(ref, () => ({
getData: getData,
}));
const getData = () => {
return data;
}
return <div></div>;
};
export default React.forwardRef(AddressComponent);
and you can get data in your parent and in submit like this:
const ParentComponent = () => {
const AddressRef = useRef(null);
const handleSubmit = (event) => {
event.preventDefault();
const data = AddressRef.current.getData();
}
return (
<form onSubmit={handleSubmit}>
<div>
<label>Name</label>
<input />
</div>
<div>
<label>Age</label>
<input />
</div>
<div>
<label>Gender</label>
<input />
</div>
<AddressComponent ref={AddressRef} />
<button type='submit'>
Submit
</button>
</form>
)
}

Clear value into input using useState or useRef (React)

I got hook:
const [myName, setMyName] = useState("");
const myNameRef = useRef();
Then I have form:
<form onSubmit={(e) => addVist(e, user.id)}>
<input type="text" name="myName" ref={myNameRef} onChange={e => setMyName(e.target.value)} />
<input type="submit" value="Run" />
</form>
And method:
const addVist = (e, userId) => {
e.preventDefault();
console.log(myName)
//some code....
//clear value form
setMyName("");
//setMyName('');
//setMyName(e.target.value = "");
//myNameRef.current.value("");
}
But the setMyName("") is not working - still I see value inside input.
You missed binding myName as value attribute of the input tag.
<input type="text" name="myName" value={myName} ref={myNameRef} onChange={e => setMyName(e.target.value)} />
Here is a complete example of clearing input using state OR a reference:
export default function App() {
const [value, setValue] = useState("");
const inputRef = useRef();
return (
<>
<input value={value} onChange={(e) => setValue(e.target.value)} />
<input ref={inputRef} />
<button
onClick={() => {
setValue("");
inputRef.current.value = "";
}}
>
Clear
</button>
</>
);
}
Refer to Controlled VS Uncontrolled components.
On your text input you should pass myName into the value attribute like so
<input type="text" name="myName" value={myName} ref={myNameRef} onChange={e => setMyName(e.target.value)} />
You forgot to add myName as value.
<input type="text" name="myName" value={myName} ref={myNameRef} onChange={e => setMyName(e.target.value)} />

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