Examples - OPC UA File Providers - Write full file contents

The example below shows how to write the full contents of an OPC UA file at once, using the file provider model.

// Shows how to write the full contents of an OPC UA file at once, using the file provider model.

using System;
using System.Text;
using OpcLabs.BaseLib.Extensions.FileProviders;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.FileTransfer;

namespace UADocExamples.FileProviders._WritableFileInfo
{
    class WriteAllBytes
    {
        public static void Main1()
        {
            // Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            UAEndpointDescriptor endpointDescriptor = "opc.tcp://localhost:48030";

            // A node that represents an instance of OPC UA FileType object.
            UANodeDescriptor fileNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile";
            
            // Instantiate the file transfer client object
            var fileTransferClient = new EasyUAFileTransferClient();

            Console.WriteLine("Getting writable file info...");
            IWritableFileInfo writableFileInfo = fileTransferClient.GetWritableFileInfo(endpointDescriptor, fileNodeDescriptor);
            // From this point onwards, the code is independent of the concrete realization of the file provider, and would
            // be identical e.g. for files in the physical file system, if the corresponding file provider was used.

            // Write all contents into a specified file node.
            byte[] bytes = Encoding.UTF8.GetBytes("TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing the whole contents of a file at once.");
            try
            {
                Console.WriteLine("Writing the whole file...");
                writableFileInfo.WriteAllBytes(bytes);

                // Due to an issue in the server, the file might not be readable now, without server restart.
                Console.WriteLine("Reading the data back...");
                byte[] data = writableFileInfo.ReadAllBytes();
                Console.WriteLine(Encoding.UTF8.GetString(data));
            }
            // Methods in the file provider model throw IOException and other exceptions, but not UAException.
            catch (Exception exception)
            {
                Console.WriteLine($"*** Failure: {exception.GetBaseException().Message}");
                return;
            }

            Console.WriteLine();
            Console.WriteLine("Finished...");
        }
    }
}

# Shows how to write the full contents of an OPC UA file at once, using the file provider model.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from System.Text import *
from OpcLabs.BaseLib.Extensions.FileProviders import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.FileTransfer import *
from OpcLabs.EasyOpc.UA.Navigation import *


# Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe).
endpointDescriptor = UAEndpointDescriptor('opc.tcp://localhost:48030')

# A node that represents an OPC UA file system (a root directory).
fileNodeDescriptor = UANodeDescriptor('nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile')

# Instantiate the file transfer client object.
fileTransferClient = EasyUAFileTransferClient()

print('Getting writable file info...')
writableFileInfo = IEasyUAFileTransferExtension.GetWritableFileInfo(fileTransferClient,
                                                                    endpointDescriptor,
                                                                    UANamedNodeDescriptor(fileNodeDescriptor))
# From this point onwards, the code is independent of the concrete realization of the file provider, and would
# be identical e.g. for files in the physical file system, if the corresponding file provider was used.

# Write all contents into a specified file node.
bytes = Encoding.UTF8.GetBytes('TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing the whole contents of a '
                               'file at once.')
try:
    print('Writing the whole file...')
    IWritableFileInfoExtension.WriteAllBytes(writableFileInfo, bytes)

    # Due to an issue in the server, the file might not be readable now, without server restart.
    print('Reading the data back...')
    data = IFileInfoExtension.ReadAllBytes(writableFileInfo)
    print(Encoding.UTF8.GetString(data))

# Methods in the file provider model throw IOException and other exceptions, but not UAException.
except Exception as exception:
    print('*** Failure: ' + exception.GetBaseException().Message)
    exit()

print()
print('Finished.')

' Shows how to write the full contents of an OPC UA file at once, using the file provider model.

Imports System.Text
Imports OpcLabs.BaseLib.Extensions.FileProviders
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.FileTransfer

Namespace FileProviders._WritableFileInfo

    Friend Class WriteAllBytes

        Public Shared Sub Main1()

            ' Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            Dim endpointDescriptor As UAEndpointDescriptor = "opc.tcp://localhost:48030"

            ' A node that represents an instance of OPC UA FileType object.
            Dim fileNodeDescriptor As UANodeDescriptor =
                "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile"

            ' Instantiate the file transfer client object
            Dim fileTransferClient = New EasyUAFileTransferClient

            Console.WriteLine("Getting writable file info...")
            Dim writableFileInfo As IWritableFileInfo =
                fileTransferClient.GetWritableFileInfo(endpointDescriptor, fileNodeDescriptor)
            ' From this point onwards, the code is independent of the concrete realization of the file provider, and would
            ' be identical e.g. for files in the physical file system, if the corresponding file provider was used.

            ' Write all contents into a specified file node.
            Dim bytes As Byte() = Encoding.UTF8.GetBytes("TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing the whole contents of a file at once.")
            Try
                Console.WriteLine("Writing the whole file...")
                writableFileInfo.WriteAllBytes(bytes)

                ' Due to an issue in the server, the file might Not be readable now, without server restart.
                Console.WriteLine("Reading the data back...")
                Dim data As Byte() = writableFileInfo.ReadAllBytes()
                Console.WriteLine(Encoding.UTF8.GetString(data))

                ' Methods in the file provider model throw IOException and other exceptions, but not UAException.
            Catch exception As Exception
                Console.WriteLine("*** Failure: {0}", exception.GetBaseException.Message)
                Exit Sub
            End Try

            Console.WriteLine()
            Console.WriteLine("Finished...")
        End Sub
    End Class
End Namespace

Examples - OPC UA File Transfer

Examples - OPC UA File Transfer - Write full file contents

Conceptual

File Provider Model in OPC UA