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library_example_recursive_download_custom_error_handling 2015-12-22		library_example_recursive_download_custom_error_handling 2022-06-16 (current)
	Line 1:		Line 1:
	====== Recursively download directory tree with custom error handling ======		====== Recursively download directory tree with custom error handling ======
-	The simplest way to download a directory tree is by using ''[[library_session_getfiles\|Session.GetFiles]]'', providing path to a root of the tree as a source. This way a batch operation however stops on any error. If you need to use a custom error handling, for example to ignore any error and just continue, you need to implement walking the tree explicitly.	+	The simplest way to download a directory tree is by using ''[[library_session_getfiles\|Session.GetFiles]]'', providing path to a root of the tree as a source. This way a batch operation however stops on any error by default.
		+
		+	The following two approaches show how to override the default behaviour.
		+
		+	Particularly the first approach with ''[[library_session_queryreceived\|Session.QueryReceived]]'' event is relevant for other batch operations as well, including ''[[library_session_putfiles\|Session.PutFiles]]'' and ''[[library_session_synchronizedirectories\|Session.SynchronizeDirectories]]''.
		+
		+	===== [[queryreceived]] Handling Session.QueryReceived event =====
		+
		+	You can choose how an error is processed by handling ''[[library_session_queryreceived\|Session.QueryReceived]]'' event.
		+
		+	This example shows a basic implementation that outputs any errors encountered and continues.
		+
		+	==== C# Example ====
		+
		+	<code csharp>
		+	session.QueryReceived += (sender, e) =>
		+	{
		+	Console.WriteLine("Error: {0}", e);
		+	e.Continue();
		+	};
		+
		+	session.GetFiles("/home/user/*", @"d:\download\").Check();
		+	</code>
		+
		+	==== VB.NET Example ====
		+
		+	<code vbnet>
		+	AddHandler session.QueryReceived,
		+	Sub(sender As Object, e As QueryReceivedEventArgs)
		+	Console.WriteLine("Error: {0}", e.Message)
		+	e.Continue()
		+	End Sub
		+
		+	session.GetFiles("/home/user/*", "d:\download\").Check()
		+	</code>
		+
		+	==== [[event_powershell]] PowerShell Example ====
		+
		+	<code powershell>
		+	$session.add_QueryReceived( {
		+	Write-Host "Error: $($_.Message)"
		+	$_.Continue()
		+	} )
		+
		+	$session.GetFiles("/home/user/*", "d:\download\").Check()
		+	</code>
		+
		+	==== Upload ====
		+
		+	The same mechanism can be used for uploads with ''[[library_session_putfiles\|Session.PutFiles]]'' or synchronization with ''[[library_session_synchronizedirectories\|Session.SynchronizeDirectories]]''.
		+
		+
		+	===== [[tree_download]] Explicit Implementation of a File Tree Download =====
		+
		+	In case you need even more control over a download process, you can implement walking of a directory tree explicitly and handle each file individually, as you need.

	This example shows a basic implementation that outputs any errors encountered and continues.		This example shows a basic implementation that outputs any errors encountered and continues.

-	===== C# Example =====	+	==== C# Example ====

	<code csharp>		<code csharp>
	using System;		using System;
		+	using System.Collections.Generic;
	using System.IO;		using System.IO;
	using WinSCP;		using WinSCP;
	Line 24:		Line 79:
	UserName = "user",		UserName = "user",
	Password = "mypassword",		Password = "mypassword",
-	SshHostKeyFingerprint = "ssh-rsa 2048 xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx"	+	SshHostKeyFingerprint = "ssh-rsa 2048 xxxxxxxxxxx..."
	};		};

	Line 35:		Line 90:
	session.Open(sessionOptions);		session.Open(sessionOptions);

-	// Start recursion	+	// Enumerate files and directories to download
-	downloadDirectory(session, localPath, remotePath);	+	var opts = WinSCP.EnumerationOptions.EnumerateDirectories \|
-	···········}	+	··························WinSCP.EnumerationOptions.AllDirectories;
		+	···············IEnumerable<RemoteFileInfo> fileInfos =
		+	session.EnumerateRemoteFiles(remotePath, null, opts);

-	return 0;	+	················foreach (RemoteFileInfo fileInfo in fileInfos)
-	}	+
-	catch (Exception e)	+
-	{	+
-	Console.WriteLine("Error: {0}", e);	+
-	return 1;	+
-	}	+
-	}	+
-		+
-	private static void downloadDirectory(Session session, string localPath, string remotePath)	+
-	{	+
-	Console.WriteLine(string.Format("Downloading directory {0} ...", remotePath));	+
-		+
-	try	+
-	{	+
-	RemoteDirectoryInfo directoryInfo = session.ListDirectory(remotePath);	+
-		+
-	············foreach (RemoteFileInfo fileInfo in directoryInfo.Files)	+
-	{	+
-	string remoteFilePath = remotePath + "/" + fileInfo.Name;	+
-		+
-	if (fileInfo.IsDirectory)	+
	{		{
-	// Skip references to current and parent directories	+	string localFilePath =
-	···················if ((fileInfo.Name != ".") &;&	+	·······················RemotePath.TranslateRemotePathToLocal(
-	·······················(fileInfo.Name != ".."))	+	···························fileInfo.FullName, remotePath, localPath);
		+
		+	···················if (fileInfo.IsDirectory)
	{		{
-	// Recurse into subdirectories
-	string localDirPath = localPath + "\\" + fileInfo.Name;
-
	// Create local subdirectory, if it does not exist yet		// Create local subdirectory, if it does not exist yet
-	if (!Directory.Exists(localDirPath))	+	if (!Directory.Exists(localFilePath))
	{		{
-	Directory.CreateDirectory(localDirPath);	+	Directory.CreateDirectory(localFilePath);
	}		}
-
-	downloadDirectory(session, localDirPath, remoteFilePath);
	}		}
-	}	+	····················else
-	················else	+
-	{	+
-	Console.WriteLine(string.Format("Downloading file {0}...", remoteFilePath));	+
-	// Download file	+
-	TransferOperationResult transferResult =	+
-	session.GetFiles(session.EscapeFileMask(remoteFilePath), (localPath + "\\"));	+
-		+
-	// Did the download succeeded?	+
-	if (!transferResult.IsSuccess)	+
	{		{
-	// Print error (but continue with other files)	+	Console.WriteLine("Downloading file {0}...", fileInfo.FullName);
-	·······················Console.WriteLine(string.Format("Error downloading file {0}: {1}", remoteFilePath, transferResult.Failures[0].Message));	+	// Download file
		+	string remoteFilePath = RemotePath.EscapeFileMask(fileInfo.FullName);
		+	TransferOperationResult transferResult =
		+	session.GetFiles(remoteFilePath, localFilePath);
		+
		+	// Did the download succeeded?
		+	if (!transferResult.IsSuccess)
		+	{
		+	····························// Print error (but continue with other files)
		+	···························Console.WriteLine(
		+	································"Error downloading file {0}: {1}",
		+	fileInfo.FullName, transferResult.Failures[0].Message);
		+	}
	}		}
	}		}
	}		}
		+
		+	return 0;
	}		}
	catch (Exception e)		catch (Exception e)
	{		{
-	Console.WriteLine(string.Format("Error downloading directory {0}: {1}", remotePath, e.Message));	+	Console.WriteLine("Error: {0}", e);
		+	············return 1;
	}		}
	}		}
	Line 102:		Line 141:
	</code>		</code>

-	===== PowerShell Example =====	+	==== [[powershell]] PowerShell Example ====

	<code powershell>		<code powershell>
	param (		param (
-	# Use Generate URL function to obtain a value for -sessionUrl parameter.	+	# Use Generate Session URL function to obtain a value for -sessionUrl parameter.
-	[Parameter(Mandatory)]	+	[Parameter(Mandatory = $True)]
-	$sessionUrl = "sftp://user:mypassword;fingerprint=ssh-rsa-xx-xx-xx@example.com/",	+	$sessionUrl = "sftp://user:mypassword;fingerprint=ssh-rsa-xxxxxxxxxxx...@example.com/",
-	[Parameter(Mandatory)]	+	[Parameter(Mandatory = $True)]
	$remotePath,		$remotePath,
-	[Parameter(Mandatory)]	+	[Parameter(Mandatory = $True)]
	$localPath		$localPath
	)		)
-	·	+
-	function DownloadDirectory ($session, $localPath, $remotePath)	+	try
	{		{
-	Write-Host ("Downloading directory {0} ..." -f $remotePath)	+	# Load WinSCP .NET assembly
-		+	Add-Type -Path "WinSCPnet.dll"
		+
		+	# Setup session options from URL
		+	····$sessionOptions = New-Object WinSCP.SessionOptions
		+	$sessionOptions.ParseUrl($sessionUrl)
		+
		+	$session = New-Object WinSCP.Session
		+	$session.SessionLogPath = "session.log"
	try		try
	{		{
-	$directoryInfo = $session.ListDirectory($remotePath)	+	# Connect
		+	·······$session.Open($sessionOptions)

-	foreach ($fileInfo in $directoryInfo.Files)	+	# Enumerate files and directories to download
		+	$fileInfos =
		+	$session.EnumerateRemoteFiles(
		+	$remotePath, $Null,
		+	([WinSCP.EnumerationOptions]::EnumerateDirectories -bor
		+	[WinSCP.EnumerationOptions]::AllDirectories))
		+
		+	········foreach ($fileInfo in $fileInfos)
	{		{
-	$remoteFilePath = ($remotePath + "/" + $fileInfo.Name)	+	$localFilePath =
-	···········	+	···············[WinSCP.RemotePath]::TranslateRemotePathToLocal(
		+	···················$fileInfo.FullName, $remotePath, $localPath)
	if ($fileInfo.IsDirectory)		if ($fileInfo.IsDirectory)
	{		{
-	# Skip references to current and parent directories	+	# Create local subdirectory, if it does not exist yet
-	if (($fileInfo.Name -ne ".") -and	+	if (!(Test-Path $localFilePath))
-	($fileInfo.Name -ne ".."))	+
	{		{
-	# Recurse into subdirectories	+	New-Item $localFilePath -ItemType directory \| Out-Null
-	$localDirPath = ($localPath + "\" + $fileInfo.Name)	+
-		+
-	# Create local subdirectory, if it does not exist yet	+
-	if (!(Test-Path $localDirPath))	+
-	{	+
-	························New-Item $localDirPath -ItemType directory \| Out-Null	+
-	}	+
-		+
-	DownloadDirectory $session $localDirPath $remoteFilePath	+
	}		}
	}		}
	else		else
	{		{
-	Write-Host ("Downloading file {0}..." -f $remoteFilePath)	+	Write-Host "Downloading file $($fileInfo.FullName)..."
	# Download file		# Download file
-	$transferResult =	+	$remoteFilePath = [WinSCP.RemotePath]::EscapeFileMask($fileInfo.FullName)
-	···················$session.GetFiles($session.EscapeFileMask($remoteFilePath), ($localPath + "\"))	+	···············$transferResult = $session.GetFiles($remoteFilePath, $localFilePath)

	# Did the download succeeded?		# Did the download succeeded?
	Line 156:		Line 203:
	{		{
	# Print error (but continue with other files)		# Print error (but continue with other files)
-	Write-Host ("Error downloading file {0}: {1}" -f $remoteFilePath, $transferResult.Failures[0].Message)	+	Write-Host (
		+	························"Error downloading file $($fileInfo.FullName): " +
		+	"$($transferResult.Failures[0].Message)")
	}		}
	}		}
	}		}
-	}
-	catch [Exception]
-	{
-	Write-Host ("Error downloading directory {0}: {1}" -f $remotePath, $_.Exception.Message)
-	}
-	}
-
-	try
-	{
-	# Load WinSCP .NET assembly
-	Add-Type -Path "WinSCPnet.dll"
-
-	# Setup session options from URL
-	$sessionOptions = New-Object WinSCP.SessionOptions
-	$sessionOptions.ParseUrl($sessionUrl);
-
-	$session = New-Object WinSCP.Session
-	$session.SessionLogPath = "session.log"
-
-	try
-	{
-	# Connect
-	$session.Open($sessionOptions)
-
-	# Start recursion
-	DownloadDirectory $session $localPath $remotePath
	}		}
	finally		finally
	Line 192:		Line 215:
	$session.Dispose()		$session.Dispose()
	}		}
-	·	+
	exit 0		exit 0
	}		}
-	catch [Exception]	+	catch
	{		{
-	Write-Host $_.Exception.Message	+	Write-Host "Error: $($_.Exception.Message)"
	exit 1		exit 1
	}		}
	</code>		</code>
		+
		+	==== Upload ====
		+
		+	For an example of walking a local tree to upload files individually, see [[library_example_moves_files_keeping_directory_structure\|*]].
		+
		+	The upload example calls ''[[library_operationresultbase#check\|OperationResultBase.Check]]'', so it aborts on any error. Just replace the call with ''[[library_operationresultbase#issuccess\|OperationResultBase.IsSuccess]]'' test, as the download example above does. See [[library_session#results\|Capturing results of operations]].

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