Reactjs - Minimum boilerplate confirm modal with React context

DomingoSL
October 15, 2023
201 views
1 vote
2 Answers

I’m trying to wrap my head around the Context concept in React, I want to use it to create a reusable confirm modal with the minimum possible boilerplate (for the modal consumer), in my mind, and due to my misunderstanding of how context works (like a useState), this is what I imagine:

From the main App, you import the component and the launcher function:

import {ConfirmDialog, ShowConfirmModal} from './components/ConfirmDialog';

And inside components/ConfirmDialog.js you have:

import React, {createContext, useContext} from "react";
import {ModalDialog, Text} from "@forge/react";

const context = createContext({ isOpen: false })

export const ConfirmDialog = () => {

    const _context = useContext(context)

    return _context.isOpen && <ModalDialog header={_context.title} onClose={_context.onClose} closeButtonText='Confirm'>

        <Text>{_context.message}</Text>

    </ModalDialog>

}

export const ShowConfirmModal = (title, message, onClose) => {

    const [_context, _setContext] = useContext(context)

    _setContext({
        message, title, onClose, isOpen: true
    })

}

This will allow the consumer to add the component in the root of the document and to show it simply by calling the ShowConfirmModal function. BUT, this does not work, since I cannot use: const [_context, _setContext] = useContext(context) And now I don’t understand what will be the best approach to solve this or even if mine is correct (with some modifications).

I’m new to React and I what I want more than a solution to the issue, is an orientation, is my reasoning correct? Or am I not "thinking in React"? (I’m a MVC dev)

Tags: reactjs

Answers

First of all you need a provider component:

const DialogContext= createContext(undefined);

export const ConfirmDialogProvider = ({ children }) => {
  // declare your state here
  const [isOpen, setIsOpen] = useState(false);
  const [message, setMessage] = useState(undefined);

  return (
    <DialogContext.Provider value={{ isOpen, setIsOpen, message, setMessage }}>
      <>
        {children}
        <ModalDialog header={title} onClose={onClose} closeButtonText="Confirm">
          <Text>{message}</Text>
        </ModalDialog>
      </>
    </DialogContext.Provider>
  );
};

You then have to use your provider in an ancestor of all components that want to open a modal
e.g.

function App() {
  return (
    <ConfirmDialogProvider>
      <Other>
        <Components />
        <Here />
      </Other>
    </ConfirmDialogProvider>
  )
}

Now you can use your context:

const SomeComponent = () => {
  const { setIsOpen, setMessage } = useContext(DialogContext);
  return (
    <button
      onClick={() => {
        setIsOpen(true);
        setMessage("Title");
      }}
    >
      Open modal
    </button>
  );
};

Notes:

You can declare your modal in a separate component and use useContext(DialogContext) there, but it must be added to the tree anyway
You can group your state, so you don’t have to use multiple functions to change it
You can create a helper hook like const useDialogContext = useContext(DialogContext) so you don’t have to write that much

Your approach is correct, but there are few suggestions about how React context works
you can follow these steps to make some corrections

Create a context hook like this:
the default value should include the properties that you are accessing in your components.

const ConfirmDialogContext = createContext({
      isOpen: false,
      title: "",
      message: "",
      onClose: () => {},
    });`

Provide Component

The provider sets the values for the context

export const ConfirmDialogProvider = ({ children }) => {
  const [context, setContext] = useState({
    isOpen: false,
    title: "",
    message: "",
    onClose: () => {},
  });

  return (
    <ConfirmDialogContext.Provider value={{ ...context, setContext }}>
      {children}
    </ConfirmDialogContext.Provider>
  );
};

3.Use the context hook

ConfirmDialog component should use the useContext hook to get the context.

export const ConfirmDialog = () => {
  const { isOpen, title, message, onClose } = useContext(ConfirmDialogContext);

  return isOpen && (
    <ModalDialog header={title} onClose={onClose} closeButtonText='Confirm'>
      <Text>{message}</Text>
    </ModalDialog>
  );
};

Show Confirmation Modal

export const ShowConfirmModal = (title, message, onClose) => {
  const { setContext } = useContext(ConfirmDialogContext);

  setContext({
    isOpen: true,
    title,
    message,
    onClose,
  });
};

Finally use that ConfrimDialogProvider in APP funtion

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Reactjs – Minimum boilerplate confirm modal with React context

Answers