Co-routine flow wrapper
from the CommonsWare Community archivesAt April 6, 2021, 9:08pm, Jan asked:
I have read your 0.3 co-routine book.
In this book you say, “There are two extension functions for ReceiveChannel that wrap it in a Flow :
receiveAsFlow() and consumeAsFlow()”
You don’t give an example. Is the below code how you would wrap it:
Original:
val notifyChannel: ReceiveChannel
Wrapper:
val notifyFlow: ReceiveChannel.receiveAsFlow()
I have an extension operator on ReceiveChannel. Can I move that extension operator to Flow?
Further regarding operators, you say:
"Channel ,
and its various subtypes like BroadcastChannel , has a lot of extension
functions that serve as operators, much like the ones we have for Flow . However,
most, if not all, are marked as deprecated. In general, the expectation now is that
you will do any “heavy lifting” using a Flow , perhaps one adapted from a Channel .
"
To “adapt” a BroadcastChannel or a regular channel, do I use a wrapper like for ReceiveChannel
or do I have to rewrite that code?
example:
private val characteristicChangedChannel =
BroadcastChannel(1488)
private val readDescChannel = Channel<GattResponse>()
At April 6, 2021, 9:42pm, mmurphy replied:
No, it would be more like:
val notifyChannel: ReceiveChannel = TODO("you need to initialize this!")
val notifyFlow = notifyChannel.receiveAsFlow()
Sorry, but since I do not know what the extension function does, I cannot tell you if the same code that works with a ReceiveChannel will work with a Flow.
ReceiveChannel is an interface. Channel extends ReceiveChannel. So, you can wrap a Channel in a Flow via receiveAsFlow() or consumeAsFlow().
BroadcastChannel has an asFlow() extension function.