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Flow control in nested flows and Composer

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A nested (pipeline) flow runs its child steps in order. Flow control lets you change that order at runtime: skip ahead to a later step, jump to a named step computed from a script, or end the rest of the steps entirely. Each control action is guarded by a condition — if the condition is false, the action is skipped and the next step runs as usual.

Flow control works in both the Composer canvas and the classic nested-flow editor. It complements two related capabilities:

Flow control decides what happens after a step finishes — it's a post-execution gate.

The four flow-control actions

Action What it does
Continue (default) Run the next step. The same as no flow control at all.
Go to step (fixed) Jump to a specific step by index. The intermediate steps are skipped.
Dynamic goto Jump to a step whose name or number is computed by a JavaScript / Python snippet. The snippet returns a step name (e.g., "Load failed records") or the keyword END.
End Stop the nested flow. Remaining steps are not run.

Every action except Continue is paired with condition — a JavaScript / Python snippet that returns true or false. If the condition is empty or evaluates to true, the action fires; otherwise the next step runs normally.

Configure flow control in the nested flow editor

  1. Open the nested flow.
  2. Click a step to open the step inspector on the right.
  3. Scroll to After this flow.
  4. Pick an action:
    • Continue — no flow control.
    • Go to step — the Go to step dropdown appears with the list of step indices. Pick the target.
    • Dynamic goto — a code editor appears. Set value to the target step name or the keyword END.
    • End — the rest of the steps are skipped.
  5. Optionally add a Condition — the action only fires when the condition evaluates true.
  6. Save the step.

Configure flow control in Composer

In Composer, the same After this flow options appear in the canvas-side inspector when you select a nested-flow step. The configuration is identical to the classic editor; Composer renders the control as an arrow on the canvas so the routing is visually obvious.

You can drag&drop Control Icon from tools sidebar to the block of nested flow step.

Examples

Skip the rest on no records

Step 1 extracts records from a source. If there's nothing to process, skip the remaining load steps:

  • Step 1: extract records.
  • Step 1 flow control: End with condition etlConfig.getValue('extracted_count') == 0.
  • Step 2: load to staging (only runs when there are records).
  • Step 3: load to warehouse.

Branch by source type

Different load logic per source type, decided at the end of a setup step:

  • Step 1: read source-type from a configuration table.

  • Step 1 flow control: Dynamic goto with snippet:

    var sourceType = etlConfig.getValue('source_type');
if (sourceType == 'salesforce') value = 'Load Salesforce';
else if (sourceType == 'database') value = 'Load Database';
else value = 'END';
  • Step 2: load Salesforce (named "Load Salesforce").
  • Step 3: load Database (named "Load Database").

Retry chain

If a step fails its post-load validation, jump back to the load step:

  • Step 1: load data.
  • Step 2: validate.
  • Step 2 flow control: Go to step 1 with condition etlConfig.getValue('validation_failed') && etlConfig.getValue('retry_count') < 3.
  • Step 3: report success.

Notes and limitations

  • Self-references are rejected — a step cannot jump to itself directly. Wrap the step in a nested flow if you need a tight loop.
  • Forward / backward jumps are both allowed. Use them carefully — backward jumps without a condition create infinite loops.
  • Dynamic goto failures (unknown step name, runtime error in the snippet) abort the flow with an error.
  • For iterating (process many items), prefer Looping in Workflows. Flow control is for routing, not for iteration.

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