Go - Websocket.Send()

Send a message from the websocket to a connection.

import (
"context"
"fmt"
"github.com/nitrictech/go-sdk/nitric"
)
func main() {
ws, err := nitric.NewWebsocket("public")
if err != nil {
return
}
ws.Send(context.TODO(), "D28BA458-BFF4-404A", []byte("Hello World"))
nitric.Run()
}

Parameters

  • Name
    ctx
    Required
    Required
    Type
    context
    Description

    The context of the call, used for tracing.

  • Name
    connectionId
    Required
    Required
    Type
    string
    Description

    The ID of the connection which should receive the message.

  • Name
    message
    Required
    Required
    Type
    []byte
    Description

    The message that should be sent to the connection.

Examples

Broadcasting a message to all connections.

Do not send messages to a connection during it's connect callback, if you need to acknowledge connection, do so by using a topic

import (
"fmt"
"github.com/nitrictech/go-sdk/faas"
"github.com/nitrictech/go-sdk/nitric"
)
func main() {
ws, err := nitric.NewWebsocket("public")
if err != nil {
return
}
connections, err := nitric.NewCollection("connections").With(nitric.CollectionEverything...)
if err != nil {
return
}
// Register a new connection on connect
ws.On(faas.WebsocketConnect, func(ctx *faas.WebsocketContext, next faas.WebsocketHandler) (*faas.WebsocketContext, error) {
err := connections.Doc(ctx.Request.ConnectionID()).Set(ctx.Request.Context(), map[string]interface{}{
"connectionId": ctx.Request.ConnectionID(),
})
if err != nil {
return ctx, err
}
return next(ctx)
})
// Remove a registered connection on disconnect
ws.On(faas.WebsocketDisconnect, func(ctx *faas.WebsocketContext, next faas.WebsocketHandler) (*faas.WebsocketContext, error) {
err := connections.Doc(ctx.Request.ConnectionID()).Delete(ctx.Request.Context())
if err != nil {
return ctx, err
}
return next(ctx)
})
// Broadcast message to all the registered websocket connections
ws.On(faas.WebsocketMessage, func(ctx *faas.WebsocketContext, next faas.WebsocketHandler) (*faas.WebsocketContext, error) {
connectionStream, err := connections.Query().Stream(ctx.Request.Context())
if err != nil {
return ctx, err
}
for {
res, err := connectionStream.Next()
if err != nil {
break // reached the end of the documents
}
connectionId, ok := res.Content()["connectionId"].(string)
if !ok {
continue
}
err = ws.Send(ctx.Request.Context(), connectionId, ctx.Request.Data())
if err != nil {
return ctx, err
}
}
return next(ctx)
})
nitric.Run()
}
Last updated on Oct 11, 2024