Building Reactive React Native apps with GraphQL

Trocki describes how backend latency and failures create loading states and other challenges in mobile apps. He says unreliable backends were identified as a cause of cross-platform project failures in a 2016 Gartner survey, and uses custom APIs as an example of integration work that varies from project to project.

Trocki presents client-side GraphQL as a way to add typed queries and resolvers without rebuilding the server. Apollo Link REST can route a GraphQL query to a REST endpoint; local resolvers offer more control over formatting and can work with app state, REST, or the cache.

GraphQL clients use normalized caches to map returned data into entities that can be reused across views. Fetch policies control when the client reads from cache or requests the network, while optimistic responses let the UI render expected data before the server responds. Apollo watch queries can observe cache changes and update components as mutations, polling, or subscriptions refill the cache.

Trocki describes GraphQL CLI and Graphback as tools for generating typed code and CRUD queries from data models. The generated queries and server can be connected to a React Native client and a Node backend, reducing repeated setup so teams can focus on business logic. Schemas can also support generated forms and deployment templates.

For more advanced setups, Trocki discusses GraphQL subscriptions and delta queries. Subscriptions provide real-time updates but typically need a reactive backend; Graphback can generate subscriptions that filter updates for specific entities. Delta queries combine with pagination to retrieve changes for entities currently in view while limiting data transfer.