Class ForEachActionWorker<TItem>

A worker that executes a callback once for each item in an IEnumerable<T>. The callback can optionally create child workers, which will be removed after each iteration, except on the last iteration, allowing them to be inspected.

Less commonly, child workers can also be added (typically by the worker parent) before the worker runs, in which case they will run on the first iteration (if any), but not on later iterations.

Any failure status returned from the user callback or escalated from worker children will halt the iteration. One can suppress Error escalation on selected child workers (by setting EscalateError to false), e.g. to implement retry-on-error functionality.

Note that if a dedicated parent worker is not needed (e.g. to group child workers), and all child workers can be created before any child worker is started, it is simpler to instead use a regular foreach statement to perform the work, e.g. creating child workers. See Instantiating Workers via Looping for details.

Inheritance

Object

WorkerParent

WorkerBase

WorkerBase<ForEachActionWorker<TItem>>

ForEachActionWorker<TItem>

Implements

IDisposeOnFinished

Inherited Members

WorkerBase<ForEachActionWorker<TItem>>.AddCompletedCallback(Func<ForEachActionWorker<TItem>, OutcomeStatus, Task<OutcomeStatus>>)

WorkerBase<ForEachActionWorker<TItem>>.AddRanCallback(Func<ForEachActionWorker<TItem>, OutcomeStatus, WorkerParentChildrenState, Task<OutcomeStatus>>)

WorkerBase<ForEachActionWorker<TItem>>.AddStartingCallback(Func<ForEachActionWorker<TItem>, Task<ProgressStatus>>)

WorkerBase.AddCompletedCallback(Func<WorkerBase, OutcomeStatus, Task<OutcomeStatus>>)

WorkerBase.AddRanCallback(Func<WorkerBase, OutcomeStatus, WorkerParentChildrenState, Task<OutcomeStatus>>)

WorkerBase.AddStartingCallback(Func<WorkerBase, Task<ProgressStatus>>)

WorkerBase.DefaultIsStartable()

WorkerBase.ErroredPortErrorsWorkerProtected

WorkerBase.ErrorOutputs

WorkerBase.EscalateError

WorkerBase.Inputs

WorkerBase.IsStartable

WorkerBase.Outputs

WorkerBase.Parent

WorkerBase.SucceededSequence<TLastWorker>(WorkerBase, WorkerBase, WorkerBase, WorkerBase, WorkerBase, TLastWorker)

WorkerBase.SucceededSequence<TLastWorker>(WorkerBase, WorkerBase, WorkerBase, WorkerBase, TLastWorker)

WorkerBase.SucceededSequence<TLastWorker>(WorkerBase, WorkerBase, WorkerBase, TLastWorker)

WorkerBase.SucceededSequence<TLastWorker>(WorkerBase, WorkerBase, TLastWorker)

WorkerBase.SucceededSequence<TLastWorker>(WorkerBase, TLastWorker)

WorkerBase.SucceededSequence<TLastWorker>(TLastWorker)

WorkerParent.AddChildCompletedCallback(Action<WorkerBase>)

WorkerParent.AddStartingChildrenCallback(Func<WorkerParent, Task<ProgressStatus>>)

WorkerParent.Children

WorkerParent.DisposeOnFinished<TDisposable>(TDisposable)

WorkerParent.GetDownstreamFactory<TInput>()

WorkerParent.HasChildren

WorkerParent.IsCanceled

WorkerParent.IsCompleted

WorkerParent.IsCreated

WorkerParent.IsError

WorkerParent.IsFailed

WorkerParent.IsFatal

WorkerParent.IsRunning

WorkerParent.IsSucceeded

WorkerParent.KeepChildrenLevels

WorkerParent.Locator

WorkerParent.LogFactory

WorkerParent.Logger

WorkerParent.MaxRunningChildren

WorkerParent.Name

WorkerParent.RemoveChildren()

WorkerParent.RescheduleChildren()

WorkerParent.RunChildrenAsync(Boolean)

WorkerParent.RunChildrenAsync()

WorkerParent.Status

WorkerParent.Item[String]

WorkerParent.ToString()

WorkerParent.WorkerSystem

WorkerParent.DebugCommands

WorkerParent.AggregateErrorOutputRows

WorkerParent.AggregateOutputRows

WorkerParent.AggregateWorkersCompleted

WorkerParent.InstantCompleted

WorkerParent.InstantCreated

WorkerParent.InstantStarted

WorkerParent.RunningDuration

Namespace: actionETL

Assembly: actionETL.dll

Syntax

public class ForEachActionWorker<TItem> : WorkerBase<ForEachActionWorker<TItem>>, IDisposeOnFinished

Type Parameters

Name	Description
TItem	The type of each item in the IEnumerable<T>.

Constructors

ForEachActionWorker(WorkerParent, String, IEnumerable<TItem>, Action<ForEachActionWorker<TItem>, TItem>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an action synchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, IEnumerable<TItem> enumerable, Action<ForEachActionWorker<TItem>, TItem> iterateAction)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Action<ForEachActionWorker<TItem>, TItem>	iterateAction	The synchronous action to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an function synchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus> iterateFunc)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus>	iterateFunc	The synchronous function to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an function asynchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>> iterateFuncAsync)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>>	iterateFuncAsync	The asynchronous function to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, Task>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an action asynchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, Task> iterateActionAsync)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, Task>	iterateActionAsync	The asynchronous action to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, Func<Boolean>, IEnumerable<TItem>, Action<ForEachActionWorker<TItem>, TItem>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an action synchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, Func<bool> isStartableFunc, IEnumerable<TItem> enumerable, Action<ForEachActionWorker<TItem>, TItem> iterateAction)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
Func<Boolean>	isStartableFunc	Function to calculate the worker start constraint; it should return true for startable and false for not startable. Defaults to startable if null.
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Action<ForEachActionWorker<TItem>, TItem>	iterateAction	The synchronous action to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, Func<Boolean>, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an function synchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, Func<bool> isStartableFunc, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus> iterateFunc)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
Func<Boolean>	isStartableFunc	Function to calculate the worker start constraint; it should return true for startable and false for not startable. Defaults to startable if null.
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, OutcomeStatus>	iterateFunc	The synchronous function to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, Func<Boolean>, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an function asynchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, Func<bool> isStartableFunc, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>> iterateFuncAsync)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
Func<Boolean>	isStartableFunc	Function to calculate the worker start constraint; it should return true for startable and false for not startable. Defaults to startable if null.
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, Task<OutcomeStatus>>	iterateFuncAsync	The asynchronous function to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

ForEachActionWorker(WorkerParent, String, Func<Boolean>, IEnumerable<TItem>, Func<ForEachActionWorker<TItem>, TItem, Task>)

Initializes a new instance of the ForEachActionWorker<TItem> worker that will execute an action asynchronously once for each item in an IEnumerable<T>.

Declaration

public ForEachActionWorker(WorkerParent workerParent, string workerName, Func<bool> isStartableFunc, IEnumerable<TItem> enumerable, Func<ForEachActionWorker<TItem>, TItem, Task> iterateActionAsync)

Parameters

Type	Name	Description
WorkerParent	workerParent	The parent worker or worker system that the new child worker will be added to. Cannot be null.
String	workerName	Name of the worker. Set to a prefix plus a trailing "/" (e.g. "MyPrefix-/") to generate a unique name from the prefix plus an increasing number starting at 1. While less useful, set to null, whitespace or "/" to generate a unique name from the worker type plus an increasing number starting at 1. The name cannot otherwise contain "/", and cannot start with double underscore "__".
Func<Boolean>	isStartableFunc	Function to calculate the worker start constraint; it should return true for startable and false for not startable. Defaults to startable if null.
IEnumerable<TItem>	enumerable	The enumerable that the worker will iterate over.
Func<ForEachActionWorker<TItem>, TItem, Task>	iterateActionAsync	The asynchronous action to execute each iteration, optionally creating child workers.

Exceptions

Type	Condition
ArgumentException	workerName: Workers with the same parent must have unique names. Worker and worker system names cannot contain '/' or start with double underscore '__'.
ArgumentNullException	workerParent - All workers must have a parent. The top level workers have the worker system as parent. enumerable
InvalidOperationException	Cannot add child worker to parent which has completed. Are you adding it to the correct parent? Cannot add worker to parent, since its children have been started. Are you adding it to the correct parent?

Methods

RunAsync()

This method can be overridden to add custom functionality to the derived worker that runs before and after the main processing. In this case, the base class base.RunAsync() must be called for the worker to function correctly.

Typically, this worker is used without overriding this method.

Declaration

protected override Task<OutcomeStatus> RunAsync()

Returns

Type	Description
Task<OutcomeStatus>	A Task describing the success or failure of the worker. An asynchronous async implementation would e.g. return OutcomeStatus.Succeeded on success, while a synchronous implementation would return OutcomeStatus.SucceededTask.

Overrides

WorkerParent.RunAsync()

Implements

IDisposeOnFinished

See Also

WhileActionWorker<T>

EscalateError