#gqlclient

A GraphQL client and code generator for Go.

#Usage

gqlclient can be used as a thin GraphQL client, and can be augmented with code generation. See the GoDoc examples for direct usage.

#GraphQL schema code generation

The code generator can parse a GraphQL schema and generate Go types. For instance, the following schema:

type Train {
	name: String!
	maxSpeed: Int!
	weight: Int!
	linesServed: [String!]!
}

and the following gqlclientgen invocation:

gqlclientgen -s schema.graphqls -o gql.go -n rail

will generate the following Go type:

type Train struct {
	Name string
	MaxSpeed int32
	Weight int32
	LinesServed []string
}

which can then be used in a GraphQL query:

op := gqlclient.NewOperation(`query {
	train(name: "Shinkansen E5") {
		name
		maxSpeed
		linesServed
	}
}`)

var data struct {
	Train rail.Train
}
if err := c.Execute(ctx, op, &data); err != nil {
	log.Fatal(err)
}
log.Print(data.Train)

#GraphQL query code generation

The code generator can also parse a GraphQL query document and generate Go functions. For instance, the following query document:

query fetchTrain($name: String!) {
	train(name: $name) {
		maxSpeed
		linesServed
	}
}

and the following gqlclientgen invocation:

gqlclientgen -s schema.graphqls -q queries.graphql -o gql.go -n rail

will generate the following function:

func FetchTrain(client *gqlclient.Client, ctx context.Context, name string) (Train, error)

which can then be used to execute the query:

train, err := rail.FetchTrain(c, ctx, "Shinkansen E5")
if err != nil {
	log.Fatal(err)
}
log.Print(train)

#GraphQL schema introspection

gqlclient also supports fetching GraphQL schemas through GraphQL introspection. For instance, the following gqlintrospect invocation will fetch the GraphQL schema of the https://example.com/query GraphQL endpoint:

gqlintrospect https://example.com/query > schema.graphqls

#Contributing

Send patches on the mailing list. Discuss in #emersion on Libera Chat.

#License

MIT