Uselazyquery refetch from child - JavaScript

In React applications, when using uselazyquery to fetch data from a GraphQL endpoint, the refetch method can be used to fetch new data whenever it is needed. However, if you want to refetch data from a child component, you need to pass the refetch method down as a prop.

This can become cumbersome if the component tree is deep, and it can be hard to manage the passing of the refetch method through multiple layers of components.

Fortunately, useLazyQuery provides us with an easy way to solve this problem. Instead of passing the refetch method down through the component tree, we can simply pass the refetch function to the child component as a prop. This way, the child component can call the refetch function whenever it needs to fetch fresh data.

Here's an example of how to do this:

import { useLazyQuery } from '@apollo/client';
import { gql } from 'graphql-tag';

function ParentComponent() {
  const [getUsers, { loading, error, data }] = useLazyQuery(gql`
    query getUsers($limit: Int) {
      users(limit: $limit) {
        id
        name
        email
      }
    }
  `);

  if (loading) return <p>Loading...</p>;
  if (error) return <p>Error :(</p>;

  return (
    <div>
      <ChildComponent refetch={getUsers} />
      <ul>
        {data.users.map((user) => (
          <li key={user.id}>
            {user.name} - {user.email}
          </li>
        ))}
      </ul>
    </div>
  );
}

function ChildComponent({ refetch }) {
  function handleClick() {
    refetch({ variables: { limit: 10 } });
  }

  return <button onClick={handleClick}>Refetch Users</button>;
}

In the example above, the getUsers function returned by useLazyQuery is passed down to the ChildComponent as a prop called refetch. In the ChildComponent, refetch is used as the callback function for a button's onClick event handler. When the button is clicked, the refetch function is called with updated variables to fetch fresh data, which is then updated in the ParentComponent's render method.

By doing this, we avoid the need to pass the refetch method multiple levels deep through the component tree, making our code cleaner and more manageable.