Class FileHelperFileTarget<TInput>

A dataflow worker with one Input port, for writing incoming data rows as delimited (e.g. CSV) or fixed format records to a file.

Note: Use the factory methods in FileHelperFileTargetFactory to create instances of this class.

Please see CSV Delimited and Fixed Format for how to specify the data format. Internally, this worker uses the http://www.filehelpers.net/ library to read the data, specifically the FileHelperAsyncEngine class.

Inheritance
Object
WorkerParent
WorkerBase
WorkerBase<FileHelperFileTarget<TInput>>
FileHelperFileTarget<TInput>
Implements
Inherited Members
Namespace: actionETL.FileHelper
Assembly: actionETL.dll
Syntax
[CLSCompliant(false)]
public class FileHelperFileTarget<TInput> : WorkerBase<FileHelperFileTarget<TInput>>, IDisposeOnFinished where TInput : class
Type Parameters
Name Description
TInput

The type of each Input row, which also defines the file format, columns, separators, column order etc. of the written data.

Properties

AppendMode

Gets or sets a value indicating whether any existing file should be overwritten or appended to. Set to true to append; false (the default) to overwrite. Cannot be set after the worker has started running.

Note: This property is thread-safe.

Declaration
public bool AppendMode { get; set; }
Property Value
Type Description
Boolean
Exceptions
Type Condition
InvalidOperationException

Cannot set the value after the worker has started running.

Engine

Gets the underlying FileHelpers FileHelperAsyncEngine instance. Use this for customizing the data transfer, such as setting the text encoding and preprocess the data records. See CSV Delimited and Fixed Format for details.

Note: Retrieving and inspecting this property is thread-safe, but modifying the Engine state is not thread-safe, and should only be done from a single thread, before the worker has started.

Declaration
public FileHelperAsyncEngine<TInput> Engine { get; }
Property Value
Type Description
FileHelpers.FileHelperAsyncEngine<TInput>

The FileHelpers engine instance.
Remarks

Note that in rare cases, and only when using non-C# .NET languages, direct use of the Engine property can fail with a compile time error since the underlying FileHelpers library class (FileHelperAsyncEngine) is not CLS compliant (warning CS3003).

FileName

The filename (including optional path) to write to. Cannot be set after the worker has started running.

Note: This property is thread-safe.

Declaration
public string FileName { get; set; }
Property Value
Type Description
String
Exceptions
Type Condition
InvalidOperationException

Cannot set the value after the worker has started running.

FooterText

The footer text to write at the end of the output, if any. Defaults to the names of the members written to the output. Set it to null to not output any header text. Any non-null string will be output verbatim. Cannot be set after the worker has started running.

Note: This property is thread-safe.

Declaration
public string FooterText { get; set; }
Property Value
Type Description
String
Exceptions
Type Condition
InvalidOperationException

Cannot set the value after the worker has started running.

HeaderText

The header text to write at the start of the output, if any. Defaults to the names of the members written to the output. Set it to null to not output any header text. Any non-null string will be output verbatim. Cannot be set after the worker has started running.

Note: This property is thread-safe.

Declaration
public string HeaderText { get; set; }
Property Value
Type Description
String
Exceptions
Type Condition
InvalidOperationException

Cannot set the value after the worker has started running.

Input

Gets the input port for receiving rows from an upstream worker.

Declaration
public InputPort<TInput> Input { get; }
Property Value
Type Description
InputPort<TInput>

Methods

RunAsync()

This method can be overridden to add custom functionality to the derived worker that runs before and after the row 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

Implements

See Also