#react query

An increasing amount of data in our React applications is coming from remote and asynchronous sources and, even worse, continues to masquerade as "global state". In this talk, you'll get the lowdown on why most of your "global state" isn't really state at all and how React Query can help you fetch, cache and manage your asynchronous data with a fraction of the effort and code that you're used to.

In this talk, I'll explain React Query from a different perspective. After having maintained React Query for over two years and having answered many questions (often the same ones multiple times), I feel like there might be a fundamental understanding missing about the lib. I'll start with a quick introduction about my journey into open source and how I got to know React Query, followed by showing which mindset change is beneficial when working with React Query - how to "think in React Query". 
I'll have 3 major takeaways: 
1) React Query is not a data fetching library It's an async state manager, we'll quickly talk about what makes a state manager, why React Query is one and what "async state" means. 
2) staleTime is your best friend I've seen a bit of confusion about how to use React Query as a state manager, so I'll explain why setting staleTime is mostly all you need 
3) parameters are dependencies This is important to understand to show the boundaries between client state and server state, and is essential when doing state management with React Query I will then end with a note on "separation of concerns" and about the tradeoffs of just calling `useQuery` wherever you need it in your component tree.

A lot of React applications out there run for state management solutions such as Redux or Mobx and use it mostly for server side state like 'isLoading', 'isError', etc. We need to stop mixing between server state and client state. Don't get me wrong, client state is important, but 70% of the state is actually a server state. In this talk I will demonstrate how we can encapsulate server state using our own custom hook or using a (perfect) solution such as react-query.

React Query manages server state on the client, and auth manages user sign in/sign up/sign out. Where do these two overlap, and how do you separate concerns? This talk proposes a data flow with custom hooks for both auth and React Query to manage authentication status and user profile updates.

Since React Summit last year, React Query has already become one of the most popular and powerful data fetching libraries for React. To celebrate, we'll be going behind the scenes to see how React Query actually works and even build our own useQuery hook in just 150 lines of code.