temporal.workflow — io.github.manetu/temporal-sdk 1.0.2

Methods for defining and implementing Temporal workflows

await clj

(await pred)

(await duration pred)

Efficiently parks the workflow until 'pred' evaluates to true. Re-evaluates on each state transition

default-version clj

defworkflow clj macro

(defworkflow name params* & body)

Defines a new workflow, similar to defn, expecting a 1-arity parameter list and body. Should evaluate to something serializable, which will become available for temporal.client.core/get-result.

Arguments:

• args: Passed from 'params' to temporal.client.core/start or temporal.client.core/signal-with-start

(defworkflow my-workflow
    [{:keys [foo]}]
    ...)

(let [w (create-workflow client my-workflow {:task-queue ::my-task-queue})]
   (start w {:foo "bar"}))

get-info clj

(get-info)

Return info about the current workflow

get-version clj

(get-version change-id min max)

Used to safely perform backwards incompatible changes to workflow definitions

invoke clj

(invoke workflow params)

(invoke workflow params options)

Invokes a 'child workflow' with 'params' from within a workflow context. Returns a promise that when derefed will resolve to the evaluation of the defworkflow once the workflow concludes.

Arguments:

• workflow: A reference to a symbol registered with defworkflow, called a Child Workflow usually.
• params: Opaque serializable data that will be passed as arguments to the invoked child workflow
• options: See below.

options map

Value	Description	Type	Default
:task-queue	Task queue to use for child workflow tasks	String
:workflow-id	Workflow id to use when starting	String
:workflow-id-reuse-policy	Specifies server behavior if a completed workflow with the same id exists	See workflow id reuse policy types below
:parent-close-policy	Specifies how this workflow reacts to the death of the parent workflow	See parent close policy types below
:workflow-execution-timeout	The time after which child workflow execution is automatically terminated	Duration	10 seconds
:workflow-run-timeout	The time after which child workflow run is automatically terminated	Duration
:workflow-task-timeout	Maximum execution time of a single workflow task	Duration
:retry-options	RetryOptions that define how child workflow is retried in case of failure	temporal.common/retry-options
:cron-schedule	A cron schedule string	String
:cancellation-type	In case of a child workflow cancellation it fails with a CanceledFailure	See cancellation types below
:memo	Specifies additional non-indexed information in result of list workflow	String

cancellation types

Value	Description
:try-cancel	Initiate a cancellation request and immediately report cancellation to the parent
:abandon	Do not request cancellation of the child workflow
:wait-cancellation-completed	Wait for child cancellation completion
:wait-cancellation-requested	Request cancellation of the child and wait for confirmation that the request was received

parent close policy types

Value	Description
:abandon	Do not request cancellation of the child workflow
:request-cancel	Request cancellation of the child and wait for confirmation that the request was received
:terminate	Terminate the child workflow

workflow id reuse policy types

Value	Description
:allow-duplicate	Allow starting a child workflow execution using the same workflow id.
:allow-duplicate-failed-only	Allow starting a child workflow execution using the same workflow id, only when the last execution's final state is one of [terminated, cancelled, timed out, failed]
:reject-duplicate	Do not permit re-use of the child workflow id for this workflow.
:terminate-if-running	If a workflow is running using the same child workflow ID, terminate it and start a new one. If no running child workflow, then the behavior is the same as ALLOW_DUPLICATE

(defworkflow my-workflow
   [ctx {:keys [foo] :as args}]
   ...)

(invoke my-workflow {:foo "bar"} {:start-to-close-timeout (Duration/ofSeconds 3))

register-query-handler! clj

(register-query-handler! f)

Registers a DynamicQueryHandler listener that handles queries sent to the workflow, using temporal.client.core/query.

Use inside a workflow definition with 'f' closing over the workflow state (e.g. atom) and evaluating to results in function of the workflow state and its 'query-type' and 'args' arguments.

Arguments:

• f: a 2-arity function, expecting 2 arguments, evaluating to something serializable.

f arguments:

• query-type: keyword
• args: params value or data structure

(defworkflow stateful-workflow
  [{:keys [init] :as args}]
  (let [state (atom init)]
    (register-query-handler! (fn [query-type args]
                               (when (= query-type :my-query)
                                 (get-in @state [:path :to :answer]))))
    ;; workflow implementation
    ))

sleep clj

(sleep duration)

Efficiently parks the workflow for 'duration'