Iteration

IterationFlow migrates a large collection one page at a time. IterationStep reads and processes the page, then passes the next page token as the input of its next execution. When there is no token, the Flow completes. This is structurally similar to timer polling, but the loop carries pagination state.

Definition graph

IterationFlow

Valid

python · examples/python/dex_examples/patterns/polling/iteration_flow.py

IterationFlow

IterationStepSTART

?

gracefulComplete

goTo

🧩 IterationStep

Press enter or space to select a node. You can then use the arrow keys to move the node around. Press delete to remove it and escape to cancel.

Press enter or space to select an edge. You can then press delete to remove it or escape to cancel.

Core implementation

class IterationStep(Step[str]):
    def execute(self, context: Context, page_token: str) -> StepDecision:
        next_page_token = (
            "page-2"
            if not page_token
            else "page-3"
            if page_token == "page-2"
            else ""
        )
        if not next_page_token:
            return graceful_complete()
        return go_to(IterationStep, next_page_token)

Example: examples/python/dex_examples/patterns/polling/iteration_flow.py