React Query is a powerful state management library for React that makes it easy to fetch, cache, and update data from a variety of sources. GraphQL is a modern API specification that allows you to query data from a server in a flexible and efficient way.
When used together, React Query and GraphQL can make it easy to build fast, reliable, and maintainable React applications. In this blog post, we will discuss some best practices and tips for using React Query with GraphQL.
Practices
Here are some best practices for using React Query with GraphQL:
Use the useQuery hook to fetch data from your GraphQL API.
The useQuery hook is the most basic way to fetch data from your GraphQL API. It takes two arguments: the query string and the options object. The query string is a GraphQL query that will be sent to your API. The options object allows you to configure the behavior of the useQuery hook, such as the cache duration and the error handling.
For example, the following code fetches the todos query from the GraphQL API and stores the results in the todos variable:
JavaScript
const todos = useQuery(“todos”);
The todos variable will be an array of objects representing the todos. If the data is not already in the cache, it will be fetched from the API. If the data is already in the cache, it will be returned from the cache.
Use the useMutation hook to mutate data on your GraphQL API.
The useMutation hook is the most basic way to mutate data on your GraphQL API. It takes two arguments: the mutation string and the options object. The mutation string is a GraphQL mutation that will be sent to your API. The options object allows you to configure the behavior of the useMutation hook, such as the cache duration and the error handling.
For example, the following code creates a new todo with the title My new todo and the description This is my new todo:
JavaScript
const [createTodo, { data, error }] = useMutation(“createTodo”);
const handleSubmit = () => {
  createTodo({
    title: “My new todo”,
    description: “This is my new todo”,
  });
};
The createTodo function will be called when the user clicks the Submit button. The data variable will contain the data returned from the API, if any. The error variable will contain an error object, if any.
Use the useQueryCache hook to access the cache directly.
The useQueryCache hook allows you to access the cache directly. This can be useful for more advanced use cases, such as caching data from multiple sources or implementing custom caching strategies.
For example, the following code fetches the todos query from the GraphQL API and stores the results in the todos variable:
JavaScript
const todos = useQuery(“todos”);
const todosCache = useQueryCache();
todosCache.set(“todos”, todos);
The todosCache variable will be an instance of the QueryCache class. The set method allows you to set a value in the cache.
Use the useQueryOptions object to configure the behavior of the useQuery hook.
The useQueryOptions object allows you to configure the behavior of the useQuery hook. The following are some of the options that you can configure:
- cacheTime: The amount of time to keep the data in the cache before refreshing it.
- errorHandler: A function that will be called when an error occurs while fetching the data.
- refetchInterval: The interval at which to refetch the data from the API.
For example, the following code configures the useQuery hook to refetch the data from the API every 10 seconds:
JavaScript
const todos = useQuery(“todos”, {
  refetchInterval: 10000,
});
Tips
Here are some tips for using React Query with GraphQL:
- Use a normalized cache. A normalized cache is a cache that stores data in a format that is easy to query. This can improve performance by reducing the number of times you need to fetch data from your GraphQL API. For example, if you have a list of users, you could store the users in a normalized cache as an array of objects. This would allow you to quickly query for a specific user by their ID or name.
- Use optimistic updates. Optimistic updates are a technique that allows you to update the UI with the latest data even before the data has been confirmed by the server. This can improve the user experience by making the UI feel more responsive. For example, if you are loading a list of users, you could optimistically update the UI with the list of users even before the list has been loaded from the server. If the list of users cannot be loaded from the server, the UI will automatically revert to the previous state.
- Use stale-while-refetching. Stale-while-refetching is a technique that allows you to keep the UI up-to-date while data is being fetched from the server. This can improve the user experience by preventing the UI from becoming unresponsive while data is being fetched. For example, if you are loading a list of users, you could use stale-while-refetching to keep the UI up-to-date with the latest data from the server. Even if the server is slow to respond, the UI will still be able to display the latest data that has been fetched from the cache.
- Use a consistent naming convention for your queries and mutations. This will make it easier to understand your code and debug any problems that may occur. For example, you could use the following naming convention for your queries: getUsers and getSingleUser. You could use the following naming convention for your mutations: createUser and updateUser.
- Use comments to document your code. This will make it easier for other developers to understand your code and maintain your application. For example, you could add a comment to the getUsers query that explains what the query does and what data it returns. You could add a comment to the createUser mutation that explains what the mutation does and what data it updates.
- Use unit tests to test your code. This will help you to ensure that your code is working correctly and that it is not introducing any new bugs. For example, you could write a unit test for the getUsers query that checks to see if the query returns the expected data. You could write a unit test for the createUser mutation that checks to see if the mutation updates the data correctly.
- Keep your code up-to-date. React Query and GraphQL are constantly being improved, so it is important to keep your code up-to-date with the latest versions of these libraries. You can do this by using a package manager like npm or yarn to install the latest versions of the libraries.
Conclusion
React Query and GraphQL are powerful tools that can be used together to build fast, reliable, and maintainable React applications. By following the best practices and tips outlined in this blog post, you can get the most out of these libraries.
