Add branching logic to a job with the If/else task

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Use the If/else condition task to add boolean conditional logic to task graphs. These tasks consist of a boolean operator and a pair of operands, where the operands might reference the job or task state using configured or dynamic parameters or task values. See Parameterize jobs.

For example, suppose you have a task named process_records that maintains a count of records that are not valid in a value named bad_records, and you want to branch processing when you encounter bad records. To add this logic to your workflow, you can create an If/else condition task with an expression like {{tasks.process_records.values.bad_records}} > 0. You can then add dependent tasks based on the results of the condition.

After a job run containing an If/else condition task, you can view the result and the expression evaluation details when you view the job run details in the UI. See View job run details.

Note

  • Numeric and non-numeric values are handled differently depending on the boolean operator:
    • The == and != operators perform string comparison of their operands. For example, 12.0 == 12 evaluates to false.
    • The >, >=, and <= operators perform numeric comparisons of their operands. For example, 12.0 >= 12 evaluates to true, and 10.0 >= 12 evaluates to false.
    • Only numeric, string, and boolean values are allowed when referencing task values in an operand. Any other types will cause the condition expression to fail. Non-numeric value types are serialized to strings and are treated as strings in If/else condition expressions. For example, if a task value is set to a boolean value, it is serialized to "true" or "false".

Configure an If/else task

Add an If/else condition task from the Tasks tab in the Jobs UI by doing the following:

  1. In the Type drop-down menu, select If/else condition.
  2. Enter the operand to be evaluated in the first Condition text box. The operand can reference any of the following:
    • A job parameter variable.
    • A task parameter variable.
    • A task value.
  3. Select a boolean operator from the drop-down menu.
  4. In the second Condition text box, enter the value for evaluating the condition.
  5. Click Save task.

Configure dependencies on an If/else condition

Configure dependencies on the If/else condition task from the tasks graph in the Tasks tab by doing the following:

  1. Select the If/else condition task in the tasks graph and click + Add task.
  2. Enter details for the task. The Depends on field defaults to <task-name> (true) where <task-name> is the name of the If/else condition task.
    • Select <task-name> (false) to configure a task that runs on a false condition evaluation.

You can configure multiple tasks to run in serial or parallel based on the outcome of an If/else condition. Consider configuring Run if dependencies if you need conditionalized runs based on upstream task failures. See Configure task dependencies.