For Loop Open (Deprecated)¶
Opens a legacy for-style loop. It initializes a loop counter and passes through up to four auxiliary values to be carried across iterations. Internally it sets up a while-loop gate using the counter as the condition and must be paired with For Loop Close.
Usage¶
Use this node at the start of a deprecated for-loop sequence together with For Loop Close. Set 'remaining' to the number of iterations you want. Connect the 'flow_control' output to For Loop Close, and wire any state you want to preserve between iterations via value outputs to the corresponding 'initial_value' inputs on the close node. Prefer the newer Loop Open/Loop Close nodes for new workflows.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| remaining | True | INT | Number of iterations to perform. Used as the loop condition; iterations proceed while this value remains non-zero. The close node decrements this each cycle. | 5 |
| initial_value1 | False | WILDCARD | First carried value passed into the loop body and back to the close node each iteration. | image tensor or integer accumulator |
| initial_value2 | False | WILDCARD | Second carried value passed through the loop. | list, dict, or any data |
| initial_value3 | False | WILDCARD | Third carried value passed through the loop. | string or model handle |
| initial_value4 | False | WILDCARD | Fourth carried value passed through the loop. | boolean flag |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| flow_control | FLOW_CONTROL | Handle that identifies and links this loop instance to the matching For Loop Close. | FLOW_CONTROL token |
| remaining | INT | The current remaining-iterations counter exposed to downstream nodes. | 5 |
| value1 | * | Pass-through of initial_value1 for use inside the loop body. | integer accumulator |
| value2 | * | Pass-through of initial_value2 for use inside the loop body. | image tensor |
| value3 | * | Pass-through of initial_value3 for use inside the loop body. | dict |
| value4 | * | Pass-through of initial_value4 for use inside the loop body. | boolean |
Important Notes¶
- Deprecated: Use Loop Open and Loop Close for new workflows.
- Pairing required: Must be connected to For Loop Close via the flow_control output; otherwise the loop will not iterate.
- Counter handling: The hidden initial_value0 overrides 'remaining' on entry and is typically fed from the close node to update the counter.
- Iteration logic: The actual decrement and continuation check are performed in the For Loop Close node; this open node just initializes and forwards values.
- Type flexibility: value1–value4 accept any data type and are preserved across iterations when properly connected.
- Range limits: 'remaining' accepts 0–100000. A value of 0 means the loop will not execute.
- Error behavior: On internal errors, the node returns default outputs and no expansion of the loop graph.
Troubleshooting¶
- Loop doesn't start: Ensure 'remaining' > 0. A zero value prevents any iteration.
- No iteration occurs: Verify the flow_control output from For Loop Open is connected to For Loop Close and that the close node is configured to decrement and feed back the counter.
- State not preserved: Connect value outputs from this node to the corresponding 'initial_value' inputs on For Loop Close; mismatched or missing connections break state carry-over.
- Close node errors or missing nodes: For Loop Close relies on integer math and condition nodes; ensure the required nodes are available in your environment.
- Unexpected remaining value: The hidden initial_value0 overrides the visible 'remaining'. Check the connection from the close node feeding this hidden input.