Conditional Node

vellum.workflows.nodes.ConditionalNode

Used to conditionally determine which port to invoke next. This node exists to be backwards compatible with Vellum’s Conditional Node, and for most cases, you should extend BaseNode.Ports directly.

1	from vellum.workflows import BaseWorkflow
2	from vellum.workflows.nodes import BaseNode
3	from vellum.workflows.state import BaseState
4
5
6	class SourceNode(BaseNode):
7	pass
8
9	class MiddleNode(BaseNode):
10	class Ports(BaseNode.Ports):
11	top = Port.on_if(SourceNode.Execution.count.less_than(1))
12	bottom = Port.on_else()
13
14	class TargetNode(BaseNode):
15	pass
16
17	class MyWorkflow(BaseWorkflow):
18	graph = SourceNode >> {
19	# here we use Ports to execute the SourceNode one more time
20	# before proceeding to the TargetNode
21	MiddleNode.Ports.top >> SourceNode,
22	MiddleNode.Ports.bottom >> TargetNode,
23	}
24
25	class Outputs(BaseWorkflow.Outputs):
26	result = TargetNode.Outputs