Ooker
Ooker•12mo ago

How to send data from a child component to its sibling?

I want create an app with two forms, each form in its own component. Users type in form 1, then the data will be passed to component 2. In there it will join the data of what they type in form 2. How can I do this? Below is the code on my machine, taken from the answer from the same question in Stack Overflow. It works when using React on Stackblitz but I don't get why it's not in my machine: index.jsx 
import Form1 from "../islands/Form1.tsx";
import Form2 from "../islands/Form2.tsx";
import { Form1Provider } from "../islands/Context.tsx";

function App() {
  return (
    <Form1Provider>
      <Form1 />
      <Form2 />
    </Form1Provider>
  );
}
import Form1 from "../islands/Form1.tsx";
import Form2 from "../islands/Form2.tsx";
import { Form1Provider } from "../islands/Context.tsx";

function App() {
  return (
    <Form1Provider>
      <Form1 />
      <Form2 />
    </Form1Provider>
  );
}
Context.js 
import { createContext } from 'preact'
import { useContext, useState } from "preact/hooks";

export const Form1Context = createContext(null);

export function Form1Provider({ children }) {
  const form1State = useState('Form 1 placeholder');
  return (
    <Form1Context.Provider value={form1State}>{children}</Form1Context.Provider>
  );
}
import { createContext } from 'preact'
import { useContext, useState } from "preact/hooks";

export const Form1Context = createContext(null);

export function Form1Provider({ children }) {
  const form1State = useState('Form 1 placeholder');
  return (
    <Form1Context.Provider value={form1State}>{children}</Form1Context.Provider>
  );
}
Form1.jsx 
import { useContext, useState } from "preact/hooks";
import { Form1Context } from './Context.tsx';

export default function Form1() {
  const [form1Data, setForm1Data] = useContext(Form1Context)
    
  return (
    <textarea 
    value = {form1Data} 
    onInput={(event) => setForm1Data(event.target.value)}
    />
  );
}
import { useContext, useState } from "preact/hooks";
import { Form1Context } from './Context.tsx';

export default function Form1() {
  const [form1Data, setForm1Data] = useContext(Form1Context)
    
  return (
    <textarea 
    value = {form1Data} 
    onInput={(event) => setForm1Data(event.target.value)}
    />
  );
}
Form2.jsx 
import { useContext, useState } from "preact/hooks";
import { Form1Context } from './Context.tsx';

export default function Form2() {
  const [form1Data, setForm1Data] = useContext(Form1Context)
  const [form2Data, setForm2Data] = useState('Form 2 placeholder')
    
  return (
    <>
        <textarea 
            value = {form2Data} 
            onInput={(event) => setForm2Data(event.target.value)}
        />
        <p>The value is {form1Data} + {form2Data}</p>
    </>
  );
}
import { useContext, useState } from "preact/hooks";
import { Form1Context } from './Context.tsx';

export default function Form2() {
  const [form1Data, setForm1Data] = useContext(Form1Context)
  const [form2Data, setForm2Data] = useState('Form 2 placeholder')
    
  return (
    <>
        <textarea 
            value = {form2Data} 
            onInput={(event) => setForm2Data(event.target.value)}
        />
        <p>The value is {form1Data} + {form2Data}</p>
    </>
  );
}
The app compiles fine, but the actual result is empty.
Stack Overflow
How to send data from a child component to its sibling?
I want create an app with two forms, each form in its own component. Users type in form 1, then the data will be passed to component 2. In there it will join the data of what they type in form 2. H...
5 Replies
MaDsEn
MaDsEn•12mo ago
In your Form2 component, the line <p>The value is {form1Data} + {form2Data}</p> is not joining the two values properly. Try using curly braces and the + sign outside the string to link the values. See if this works <p>The value is {form1Data + ' ' + form2Data}</p>
Ooker
OokerOP•12mo ago
still not working besides that, do you think the code should work?
MaDsEn
MaDsEn•12mo ago
The concept is valid, but Fresh might need another data structure to make it work. I might take a look at it later on.
Ooker
OokerOP•12mo ago
https://github.com/denoland/fresh/issues/983
GitHub
unable to use preact context in fresh · Issue #983 · denoland/fresh
I managed to use preactcreateContext hook as the following: hooks/ShoppingCartProvider.tsx export const ShoppingCartContext = createContext({} as ShoppingCart); [...] return ( <ShoppingCartConte...
Ooker
OokerOP•12mo ago
I think this is relevant

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