print(_:to:)
Prints log messages for all publishing events.
Declaration
func print(_ prefix: String = "", to stream: (any TextOutputStream)? = nil) -> Publishers.Print<Self>Parameters
- prefix:
A string —- which defaults to empty -— with which to prefix all log messages.
- stream:
A stream for text output that receives messages, and which directs output to the console by default. A custom stream can be used to log messages to other destinations.
Return Value
A publisher that prints log messages for all publishing events.
Discussion
Use print(_:to:) to log messages the console.
In the example below, log messages are printed on the console:
let integers = (1...2)
cancellable = integers.publisher
.print("Logged a message", to: nil)
.sink { _ in }
// Prints:
// Logged a message: receive subscription: (1..<2)
// Logged a message: request unlimited
// Logged a message: receive value: (1)
// Logged a message: receive finished