Progressive Web Apps Development

v0.5.15 2019-06-13T17:18:54
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GraphQL is a query language and execution engine connected to any backend service.

The GraphQL is a specification of a data query developed and maintained by Facebook. The spec determines the validity of the schema on the API server. The schema determines the validity of client calls.

GraphQL is What Not How. Some attributes are:

  • Strongly typed - The schema defines an API’s type system and all object relationships

  • Introspective - A client can query the schema for details about the schema

  • Hierarchical - The shape of a GraphQL call mirrors the shape of the JSON data it returns. Nested fields retrieve only the data specify in a single query round trip

  • An application layer - GraphQL is not a storage model or a database query language. The graph refers to graph structures defined in the schema, where nodes define objects and edges define relationships between objects. The API traverses and returns application data based on the schema definitions, independent of how the data is stored.


Gatsby does GraphQL queries at compile time, so the query data is contained in the PWA

  • Static Query - Enables components to retrieve data via GraphQL query. It does not run for each page

  • Normal Query - Are run for each page

John Telford
John Telford
Portland, Oregon