execution library Null safety
Basis for GraphQL execution layer to support Link and Client.
Parsing a GraphQL file will give you a
DocumentNode, which may contain
multiple operation definitions. In such case GraphQL requires you to
explicitly define the name of the operation to be executed. It can be
done by passing
operationName to the
Operation only carries the document and the operation name,
Request respresents the invocation of an operation. Alongside the operation,
it also carries the variables.
To execute a
Request you must pass it to some execution layer.
When some execution layer has processed the
Request it returns
possibly carrying a list of errors and/or data.
Response may carry additional context. Context is used
by the execution layer.
Context is a collection of context entries. A Context may only appear once per type.
// Create a context entry final entry = FooBarContextEntry( foo: 1, bar: 2, ); // Create a context with an entry final context = Context().withEntry(entry); // Update context somewhere in the execution layer final context2 = context.updateEntry( (FooBarContextEntry entry) => FooBarContextEntry( foo: entry.foo, bar: entry.bar * 2, ), ); // Retrieve context entry somewhere else in the execution layer final fooBarEntry = context.entry<FooBarContextEntry>();
Response also exposes helper methods to work with the context.
- A Context to be passed along with a Request. [...]
- Entry in the Context. [...]
- Location of a GraphQL error in the request document
- GraphQL Error returned if execution fails
- An operation in a document, optionally defined by operationName
- Execution request of an operation with variables.
- Exposes Request extensions
- Execution response
- Extensions returned with the response