cascading.flow
Interface AssemblyPlanner

public interface AssemblyPlanner

Interface AssemblyPlanner is used to allow for lazy evaluation of a pipe assembly during planning of a Flow.

This allows for new languages or frameworks that may require additional meta-data from the underlying platform or environment. Specifically field names and type information from incoming source and outgoing sink Taps.

AssemblyPlanner implementations are handed to a FlowPlanner instance in the order they should be evaluated. Every instance has the opportunity to replace any prior tails with new branches and paths.

Every instance of AssemblyPlanner evaluated is given the current FlowDef used on the current FlowConnector, the current Flow instance (only initialized with source and sink Taps provided by the FlowDef), and the tails provided by the FlowDef or those returned by prior AssemblyPlanner instances.

An AssemblyPlanner cannot change or modify the Flow, or change out any Taps used as sources, sinks, traps, or checkpoints.

This is an experimental API and subject to change without notice.

Nested Class Summary

static interface

AssemblyPlanner.Context

Method Summary

Map<String,String>	getFlowDescriptor() Returns a map of properties giving more details about the Flow object.
List<Pipe>	resolveTails(AssemblyPlanner.Context context) Called when this AssemblyPlanner instance should return any additional tail Pipe instances for used when completing the Flow plan.

Method Detail

resolveTails

List<Pipe> resolveTails(AssemblyPlanner.Context context)

Called when this AssemblyPlanner instance should return any additional tail Pipe instances for used when completing the Flow plan.

Parameters:

context - parameter object of the Context

Returns:

tail Pipe instances to replace the given tails

getFlowDescriptor

Map<String,String> getFlowDescriptor()

Returns a map of properties giving more details about the Flow object. This can be picked up by a Flow object and added to its internal FlowDescriptor.

Returns:

Map