graphql_transport_ws

type Client ¶

type Client interface {
	// Query provides an RPC like API for performing GraphQL queries.
	Query(context.Context, *Request) (*Response, error)
}

Client provides high-level API for making GraphQL requests over WebSocket.

func NewClient(conn *Conn) Client

conn, err := Dial(context.TODO(), "ws://example.com")
if err != nil {
	// Make sure to handle the error
	return
}
defer conn.Close()

// Performing queries is completely concurrent safe.
client := NewClient(conn)

respCh := make(chan *Response)
go func() {
	resp, err := client.Query(context.TODO(), &Request{Query: "{ hello { world } }"})
	if err != nil {
		// Remember, always handle errors
		return
	}
	respCh <- resp
}()

go func() {
	resp, err := client.Query(context.TODO(), &Request{Query: "{ hello { world } }"})
	if err != nil {
		// Remember, always handle errors
		return
	}
	respCh <- resp
}()

for resp := range respCh {
	// Always check resp.Errors
	fmt.Println(resp)
}

Output:

conn, err := Dial(context.TODO(), "ws://example.com")
if err != nil {
	// Make sure to handle the error
	return
}
defer conn.Close()

client := NewClient(conn)

resp, err := client.Query(context.TODO(), &Request{Query: "{ hello { world } }"})
if err != nil {
	// Remember, always handle errors
	return
}
// Always check resp.Errors

var exampleResp struct {
	Hello struct {
		World string `json:"world"`
	} `json:"hello"`
}

err = json.Unmarshal(resp.Data, &exampleResp)
if err != nil {
	return
}

// Now, exampleResp.Hello.World would be your query result.

Output:

type CompressionMode ¶

type CompressionMode websocket.CompressionMode

CompressionMode represents the modes available to the deflate extension. See https://tools.ietf.org/html/rfc7692

A compatibility layer is implemented for the older deflate-frame extension used by safari. See https://tools.ietf.org/html/draft-tyoshino-hybi-websocket-perframe-deflate-06 It will work the same in every way except that we cannot signal to the peer we want to use no context takeover on our side, we can only signal that they should. It is however currently disabled due to Safari bugs. See https://github.com/nhooyr/websocket/issues/218

const (
	// CompressionNoContextTakeover grabs a new flate.Reader and flate.Writer as needed
	// for every message. This applies to both server and client side.
	//
	// This means less efficient compression as the sliding window from previous messages
	// will not be used but the memory overhead will be lower if the connections
	// are long lived and seldom used.
	//
	// The message will only be compressed if greater than 512 bytes.
	//
	CompressionNoContextTakeover CompressionMode = iota

	// CompressionContextTakeover uses a flate.Reader and flate.Writer per connection.
	// This enables reusing the sliding window from previous messages.
	// As most WebSocket protocols are repetitive, this can be very efficient.
	// It carries an overhead of 8 kB for every connection compared to CompressionNoContextTakeover.
	//
	// If the peer negotiates NoContextTakeover on the client or server side, it will be
	// used instead as this is required by the RFC.
	//
	CompressionContextTakeover

	// CompressionDisabled disables the deflate extension.
	//
	// Use this if you are using a predominantly binary protocol with very
	// little duplication in between messages or CPU and memory are more
	// important than bandwidth.
	//
	CompressionDisabled
)

type Conn ¶

type Conn struct {
	// contains filtered or unexported fields
}

Conn is a client connection that should be closed by the client.

func Dial(ctx context.Context, endpoint string, opts ...DialOption) (*Conn, error)

conn, err := Dial(context.TODO(), "ws://example.com")
if err != nil {
	// Make sure to handle the error
	return
}
defer conn.Close()

// Create a single client with the connection.
// There is no need to create multiple connections or clients
// because it will all be managed for you.

Output:

func (c *Conn) Close() error

type ConnOption ¶

type ConnOption interface {
	DialOption
	ServerOption
}

ConnOption represents a configuration that applies symmetrically on both sides, client and server.

func WithCompression(mode CompressionMode, threshold int) ConnOption

type DialOption ¶

type DialOption interface {
	SetDial(*dialOpts)
}

DialOption configures how we set up the connection.

func WithHTTPClient(client *http.Client) DialOption

func WithHeaders(headers http.Header) DialOption

type ErrIO ¶

type ErrIO struct {
	// Msg
	Msg string

	// Err
	Err error
}

ErrIO represents a wrapped I/O error.

func (e ErrIO) Error() string

func (e ErrIO) Unwrap() error

type ErrUnexpectedMessage ¶

type ErrUnexpectedMessage struct {
	// Expected was the expected message type.
	Expected string

	// Received was the received message type.
	Received string
}

ErrUnexpectedMessage represents a unexpected message type.

func (e ErrUnexpectedMessage) Error() string

type MessageHandler ¶

type MessageHandler func(context.Context, *Request) (*Response, error)

MessageHandler is a user provided function for handling incoming GraphQL queries. All other "GraphQL over Websocket" protocol messages are automatically handled internally. All resolvers errors should be included in *Response and any validation error should be returned as error.

type Request ¶

type Request struct {
	Query         string                 `json:"query"`
	Variables     map[string]interface{} `json:"variables"`
	OperationName string                 `json:"operationName"`
}

Request represents a payload sent from the client.

type Response ¶

type Response struct {
	Data   json.RawMessage   `json:"data"`
	Errors []json.RawMessage `json:"errors"`
}

Response represents a payload returned from the server. It supports lazy decoding by leaving the inner data for the user to decode.

type ServerError ¶

type ServerError struct {
	Msg string `json:"msg"`
}

ServerError represents a payload which is sent by the server if it encounters a non-GraphQL resolver error.

func (e *ServerError) Error() string

type ServerOption ¶

type ServerOption interface {
	SetServer(*options)
}

ServerOption allows the user to configure the handler.

func WithOrigins(origins ...string) ServerOption