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Utilizing Promises, Context and Hooks for a Modern Alternative to window.confirm

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Peter White@petewht
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Let's upgrade our clunky window.confirm to our own custom modal, whilst keeping the same confirm functionality. We'll use hooks, context and promises to do it.

Context allows your app to receive information from distant parents without passing it as props. With useContext, your app's top-level component can pass props to all components below, no matter how deep they are in the hierarchy, without endless prop drilling.

This will allow us to access our modal from anywhere in our app.

import { createContext, useContext, useRef, useState } from 'react';
 
interface ConfirmDialogProps {
  title: string;
  description: string;
  confirmText?: string;
}
 
// This is a context that is used to hold the data for the confirmation dialog
const ConfirmDialog = createContext<
  (data: ConfirmDialogProps) => Promise<boolean>
>(() => {
  throw new Error('ConfirmDialogProvider not found');
});
 
// This is a component that will wrap your app and provide the context
export function ConfirmDialogProvider({
  children,
}: {
  children: React.ReactNode;
}) {
 
  // This is the state that will hold the data of the confirmation dialog, such as the title
  const [state, setState] = useState({ visible: false });
 
  // This is a reference to the fn that will be called when the user confirms or cancels
  const fn = useRef<(choice: boolean) => void>(() => false);
 
  // This opens the modal, and returns the confirm or cancel promise
  const confirm = (data: ConfirmDialogProps): Promise<boolean> => {
    return new Promise((resolve, reject) => {
      if (state.visible) {
        reject(new Error('Confirm already called'));
      }
      setState({ ...data, visible: true });
      fn.current = (choice: boolean) => {
        resolve(choice);
        setState({ visible: false });
      };
    });
  };
 
  return (
    <ConfirmDialog.Provider value={confirm}>
      {children}
      {/* Replace me with your Modal component */}
      <Modal
        {...state}
        onCancel={() => fn.current(false)}
        onConfirm={() => fn.current(true)}
      />
    </ConfirmDialog.Provider>
  );
}
 
// We use this hook to consume the context
export default function useConfirm() {
  return useContext(ConfirmDialog);
}

Using the confirm dialog

  1. Wrap where you want to use confirm with the ConfirmDialogProvider provider
  2. Invoke as in the example code below
const confirm = useConfirm();
 
const handleDeleteAll = async () => {
  const choice = await confirm({
    title: 'Delete all',
    description: 'Are you sure you want to delete everything?',
    confirmBtnLabel: 'Yes',
  });
 
  if (choice) {
    // If true, something happens. You can optionally handle a false status
  }
};

Thanks for Reading!

I always appreciate feedback or suggestions for future blog posts. You can find me on Twitter or if you want to improve the article to help future readers, please feel free to submit a PR.

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