DSLink Scala SDK
- Provides DSAConnector and DSAConnection classes as a communication facade.
- Tracks DSA connection lifecycle through DSAEventListener interface.
- Implements DSAHelper object for basic DSA operations, such as invoke, subscribe, set, etc.
- Exposes DSA API through Reactive Streams paradigm.
- Implements fluent Scala layer to facilitate operations with DSA artifacts.
- Recognizes all existing Node API data types.
You can create a DSAConnector passing individual settings or the entire argument list:
val brokerUrl = ...
val configPath = ...
val connector = DSAConnector("-b", brokerUrl, "-d", configPath)or
def main(args: Array[String]): Unit = {
val connector = DSAConnector(args)
}You can then add listeners and initiate a new connection do DSA:
connector.addListener(new DSAEventListener {
override def onResponderConnected(link: DSLink) = println("responder link connected @ " + link.getPath)
})
val connection = connector.start(RESPONDER)
val root = connection.responderLink.getNodeManager.getSuperRoot
root createChild "counter" valueType ValueType.NUMBER value 0 build ()
...
connector.stopMost DSAHelper methods require implicit Requester or Responder object. You can use the ones provided by DSAConnection:
val connection = connector start LinkMode.DUAL
implicit val requester = connection.requester
implicit val responder = connection.responderExample calling DSA Invoke method:
DSAHelper invoke (path, key1 -> value1, key2 -> value2) subscribe (
onNext = event => println("Event received: " + event),
onError = err => println("Error occurred: " + err),
onCompleted = () => println("Stream closed, no more data")
)Example calling DSA Subscribe on multiple nodes and merging the results:
val cpu = DSAHelper watch "/downstream/System/CPU_Usage"
val mem = DSAHelper watch "/downstream/System/Memory_Usage"
cpu merge mem subscribe { sv =>
println(sv.getPath + " : " + sv.getValue)
}Note that you can subscribe to the same path multiple times using watch without raising an error.
This SDK also provides an extension to the Java NodeBuilder class to expose a simple DSL.
Example creating new nodes:
parentNode createChild "changeValue" display "Update Value" action (
createAction(
parameters = List("value" -> ValueType.NUMBER),
handler = result => {
val value = result.getParameter("value").getNumber
DSAHelper updateNode "/output/value" -> value
}
)
) build