GraphQL

Comparison to REST

• Both GQL and REST send data over HTTP
• GraphQL is client and schema driven whereas REST is more server driven
• GraqhQL client specifies response body whereas REST has static server defined responses
• REST to GraphQL Operations
  • GET -> Query
  • POST, PUT, UPDATE, DELETE -> Mutation
  • GraphQL also includes Subscription operation for pub/sub

Benefits/problems it solves

• Overfetching and Underfetching
  • Client has the ability to specify desired fields rather than always receiving a static response from a REST endpoint
  • Solves the problem of mobile applications receiving too much data over the wire
• Fewer requests needed to get all necessary information
• Useful in rapidly changing data environments
• Easily readable queries
• Subscription data pushed from the server useful when your app needs to know about live events/updates
• GraphQL Caching built into Apollo Client
• Complexity of system is hidden by GraphQL
• Allows for Alias of fields
• GraphQL has a GUI Playground for interacting with the integrated server
• Places power in the consumer to decide on the information they want
• Easily allows for extraction of business logic out of frontend

Ease of setup

• Due to the single endpoint implementation, server code only needs to expose a single route
• Apollo client can be adopted incrementally
  • Encouraged to adopt holistically
  • GraphQL can be added as a gateway on top of an existing RESTful/database implementation

Drawbacks

• Single endpoint prevents native HTTP caching
• Web caching is rather complex
  • Relies on GraphQL client to implement caching
• Queries always return HTTP code 200
• Queries can become rather complex and lead to some performance issues
• Adds complexity to apps that may otherwise be simple
• File uploading not recommended
  • Can use Base64 encoding

Learning Curve/Migration

• Learning curve is certainly higher than REST
  • Operation syntax is different
  • Resolver implementation becomes complex as data complexity increases
  • Requires different mindset when thinking about schema and resolver implementation
• However, there is extensive amount of documentation
• Apollo client
• Large adoption by community = easy to google answers

Choosing between GraphQL vs. REST

• Choose REST if:
  • Very static data structure that never changes
  • Complex queries are more manageable in REST
  • A need for easy caching of data
  • Heavily based on file uploading
• Choose GraphQL if:
  • Needs of the client drive the server implementation
  • Clients are very mobile heavy
  • Desire to minimize number of API calls per request
  • Development process is quicker after learning curve especially when frequent changes in requirements