apollo-client-patterns

Apollo Client provides useQuery and useMutation hooks for React components to fetch data and perform updates. These hooks handle loading, error, and cache states automatically, reducing boilerplate and enabling reactive updates across your component tree.

Apollo Client uses normalized cache with type policies and fetch policies to optimize data flow. Type policies define how entities are cached and updated, while fetch policies control whether to fetch fresh data or use cached results, balancing performance and consistency.

Yes, Apollo Client supports local state management through reactive variables and local-only fields in your schema. This lets you colocate UI state with server data in the same cache, eliminating the need for a separate state management layer.

Apollo Client enables pagination through offset/limit or cursor-based queries with merge functions in cache policies, and refetch through the refetch method on query results. These patterns support efficient data loading and cache updates for large datasets.

Yes, Apollo Client optimistic updates let mutations display results immediately before the server responds. You specify an optimisticResponse in the mutation, and Apollo rolls it back if the mutation fails, maintaining consistency and perceived responsiveness.

Apollo Client uses HTTP link middleware to inject auth tokens and handle authentication headers. Error handling leverages onError callbacks and link chains to intercept failures, refresh tokens, or redirect unauthenticated users before errors reach components.