sdk/org.apache.airflow.sdk/Airflow/Switch

Switch

@Target(allowedTargets = [AnnotationTarget.FUNCTION])

annotation class Switch(val id: String = "", val owner: String = "airflow", val startDate: String = "", val endDate: String = "", val triggerRule: String = "all_success", val dependsOnPast: Boolean = false, val ignoreFirstDependsOnPast: Boolean = false, val waitForPastDependsBeforeSkipping: Boolean = false, val waitForDownstream: Boolean = false, val retries: Int = 0, val queue: String = "default", val pool: String = "default_pool", val poolSlots: Int = 1, val executionTimeout: String = "", val retryDelay: String = "PT5M", val retryExponentialBackoff: Double = 0.0, val maxRetryDelay: String = "", val priorityWeight: Int = 1, val weightRule: String = "downstream", val executor: String = "", val doXcomPush: Boolean = true, val emailOnFailure: Boolean = true, val emailOnRetry: Boolean = true, val docMd: String = "", val mapIndexTemplate: String = "", val maxActiveTisPerDag: Int = -1, val maxActiveTisPerDagrun: Int = -1)

Marks a task method that chooses one of several tasks to run; every other one is skipped.

The method returns the class the Dag's builder generated for the task it chose, as Class<? extends Task>. Its wiring-view method returns a SwitchRef, so the cases are listed where the Dag is wired:

@Airflow.Switch(id = "pick_path")
public Class<? extends Task> pickPath(long rows) {
  return rows > 1000 ? EtlBuilder.HandleLong.class : EtlBuilder.HandleShort.class;
}

@Airflow.Deps
static class Wiring implements EtlDeps {
  void depends() { pickPath(extract()).Case(handleLong()).Case(handleShort()); }
}

A switch chooses exactly one case, so a task that runs after several of them needs a trigger rule that tolerates a skipped upstream, such as none_failed_min_one_success.

Configuration attributes are Task's, and apply to the deciding task.

Properties

val dependsOnPast: Boolean = false

Airflow's depends_on_past setting.

val docMd: String

Airflow's doc_md setting.

val doXcomPush: Boolean = true

Airflow's do_xcom_push setting.

val emailOnFailure: Boolean = true

Airflow's email_on_failure setting.

val emailOnRetry: Boolean = true

Airflow's email_on_retry setting.

val endDate: String

Airflow's end_date setting; an ISO-8601 date-time such as "2026-01-01T00:00:00Z".

executionTimeout

val executionTimeout: String

Airflow's execution_timeout setting; an ISO-8601 duration such as "PT5M".

val executor: String

Airflow's executor setting.

Task ID. Empty derives it from the annotated function's name.

ignoreFirstDependsOnPast

val ignoreFirstDependsOnPast: Boolean = false

Airflow's ignore_first_depends_on_past setting.

mapIndexTemplate

val mapIndexTemplate: String

Airflow's map_index_template setting.

maxActiveTisPerDag

val maxActiveTisPerDag: Int

Airflow's max_active_tis_per_dag setting.

maxActiveTisPerDagrun

val maxActiveTisPerDagrun: Int

Airflow's max_active_tis_per_dagrun setting.

val maxRetryDelay: String

Airflow's max_retry_delay setting; an ISO-8601 duration such as "PT5M".

val owner: String

Airflow's owner setting.

val pool: String

Airflow's pool setting.

val poolSlots: Int = 1

Airflow's pool_slots setting.

val priorityWeight: Int = 1

Airflow's priority_weight setting.

val queue: String

Airflow's queue setting.

val retries: Int = 0

Airflow's retries setting.

val retryDelay: String

Airflow's retry_delay setting; an ISO-8601 duration such as "PT5M".

retryExponentialBackoff

val retryExponentialBackoff: Double = 0.0

Airflow's retry_exponential_backoff setting.

val startDate: String

Airflow's start_date setting; an ISO-8601 date-time such as "2026-01-01T00:00:00Z".

val triggerRule: String

Airflow's trigger_rule setting.

waitForDownstream

val waitForDownstream: Boolean = false

Airflow's wait_for_downstream setting.

waitForPastDependsBeforeSkipping

val waitForPastDependsBeforeSkipping: Boolean = false

Airflow's wait_for_past_depends_before_skipping setting.

val weightRule: String

Airflow's weight_rule setting.