json

func Middleware ¶

func Middleware() func(ctx *velaros.Context)

Middleware provides JSON message format support for Velaros WebSocket connections. It handles parsing incoming JSON messages and serializing outgoing messages according to the Velaros JSON message envelope format.

Message Format ¶

Incoming messages should be JSON objects with the following structure:

{
  "id": "optional-message-id",      // For request/reply correlation
  "path": "/route/path",            // Required: determines which handler to execute
  "data": { /* your data here */ }  // Optional: message payload
}

Outgoing messages are automatically wrapped in an envelope:

{
  "id": "message-id",               // Present if replying or making a request
  "data": { /* your response */ }   // Your response data
}

Special Response Types ¶

The middleware provides special handling for certain response types:

• Error (string) -> {"error": "message"}
• FieldError/[]FieldError -> {"error": "Validation error", "fields": [...]}
• string -> {"message": "your string"}
• Other types -> {"data": yourData}

Usage ¶

router := velaros.NewRouter()
router.Use(json.Middleware())

router.Bind("/users/:id", func(ctx *velaros.Context) {
    var req GetUserRequest
    ctx.ReceiveInto(&req)  // Automatically uses JSON unmarshaling
    ctx.Send(user)       // Automatically serialized to JSON
})

The middleware also validates the Sec-WebSocket-Protocol header, expecting "velaros-json" if present.