Azure Service Bus trigger tutorials - Usage of the C# Library

About Azure Service Bus trigger C# library

To use C# Library

Environment Settings

• .NET Framework 3.5 or higher
• Microsoft Visual Studio with Windows Azure Tools for Microsoft Visual Studio installed
• Windows Azure AppFabric SDK V1.0

Required information for using

• Following information to connect to initiated Azure Service Bus service
  • Service Namespace(Service Namespace)
  • Service Path(Service Path)
  • Default Issuer(Default Issuer)
  • Default Key(Default Key)
• Variable name and variable type of script input variable (If you pass value to the script input variable of the executed script)
• Variable name and variable type of script output variable (If you get value from the script output variable of the executed script)

Development Flow

1. Add reference to necessary modules with Microsoft Azure C# application on Microsoft Visual Studio(using Web role or worker role)
2. Which implement ignite the trigger ( See "Using the C# program"Please for more information)
3. Deploy the developed application as a service on Microsoft Azure

Usage from C# program

References

• AppFabricTriggerService.dll
  
  • The body of the C# library.It is located at $DATASPIDER_HOME/server/lib directory .
• Microsoft.ServiceBus.dll
  
  • It is a library of Windows Azure AppFabric SDK. It is usually located at C:\Program Files\Windows Azure AppFabric SDK\V1.0\Assemblies directory.

Program flow

1. Specify the connection information, create an instance of AppFabricTriggerService.
2. Using AppFabricTriggerService.PutParam method, and parameters to pass values to script input variable.
3. The Execute method of AppFabricTriggerService is called, message is send and trigger fires.
4. Execute method's return value, get an instance of ExecutionResponse and gets the script execution result.
5. If successfully executed, gets the value of script output variable from ExecutionResponse.
6. If you fail to execute, get error information form ExecutionFailure.

Sample Program

using System;
(Omitted)
// Specify the C# Library namespace to using directive 
using Appresso.DataSpider.Service;
	
public class AppFabricTriggerTest 
{

	(Omitted)
	
	public void ExecuteDataSpiserService ()
	{
		/ / AppFabricTriggerService instantiation
		AppFabricTriggerService service = new AppFabricTriggerService (
			"ServiceNamespace", / / Service Namespace (Service Namespace) specification
			"ServicePath", / / Service path (Service Path) specification
			"defaultIssuer", / / Default Issuer (Default Issuer) specification
			"defaultKey"); / / Default Key (Default Key) specification

		// Set parameters to pass to string script input variables "string_in"
		string string_in = "Input string";
		service.PutParam("string_in", string_in);

		// Set parameters to pass to integer script input variables "int_in"
		int int_in = 200;
		service.PutParam("int_in", int_in);
		
		// Set parameters to pass to Boolean script input variables "boolean_in"
		bool boolean_in = True;
		service.PutParam("boolean_in", boolean_in);

		// Call Execute method, fire the trigger and get ExecutionResponse
		ExecutionResponse response = service.Execute();
		
		// Get the exit status from ExecutionResponse
		int exitStatus = response.ExitStatus;
		
		//Get whether the process was successful from ExecutionResponse
		bool succeeded = response.Succeeded;
		
		if (succeeded)
		{
			// If the operation was successful
			
			// Get Dictionary type instance with information of script output variables by Results property of ExecutionResponse .
			Dictionary<string, object&gt results = response.Results;
			
			//Get value from String type script output variable "string_out"
			string string_out = (string )results["string_out"];
			
			//Get value from integer type script output variable "int_out"
			int int_out = (int)results["int_out"];
			
			//Get value from Boolean type script output variable "boolean_out"
			bool boolean_out = (bool)results["boolean_out"];
			
			\\\( Omit the process of using the retrieved values) \\\
		}
		else
		{
			// If the operation fails
			
			//Get the ExecutionFailure instance with error information from Failure property of ExecutionResponse
			ExecutionFailure failure = response.Failure;
			
			/  Get the error type
			string failureType = faillure.Type;
			
			// Get the error message
			string failureMessage = faillure.Message;
			
			// Get the error details
			string failureMessage = faillure.Message;
			
			\\\( Omit the process of using the retrieved error info) \\\
			
		}
	}
	(Omitted)
}

To pass a value to a script input variable

Script input variable type	Corresponding C# type	Remarks
String	string
Integer	int
Decimal	decimal
Date/Time	System.DateTime	The value less than Ms digit is truncated.
Boolean	bool
Binary	byte[]
XML	System.Xml.XmlDocument

To get the script output variable

Main exceptions