View.OrchestratorBase 0.4.0.1

View.io Orchestrator Base Classes and Interfaces

Base classes and interfaces that must be implemented to deploy code with the View Orchestrator.

C# Requirements

Include Dependent Libraries

Install the View.OrchestratorBase NuGet package:

PM> Install-Package View.OrchestratorBase

Modify your .csproj file to include the following inside a PropertyGroup:

<CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
<PublishSingleFile>true</PublishSingleFile>
<SelfContained>true</SelfContained>

This ensures dependency and package DLLs are copied to your output directory rather than referenced as packages.

Helpful links:

• https://weblog.west-wind.com/posts/2023/May/29/Getting-NET-Library-Projects-to-Output-Dependent-Assemblies

Implement Base Class and Interface

The base class StepBase and interface IStepProcessor must be implemented to be deployed on the View Orchestrator. Your code should expect a StepRequest as its input, and return a StepResponse as its output.

using View.OrchestratorBase

public class MyClass : StepBase, IStepProcessor
{
	public async Task<StepResponse> Process(StepRequest req)
	{
		// your code here

		StepResponse resp = new StepResponse
		{
			Result = StepResultEnum.Success, // or Failure, or Exception
			Data = Encoding.UTF8.GetBytes([your data here])
		};

		return resp;
	}
}

Python Requirements

User python scripts are encapsulated into a wrapper script by the Orchestrator and executed in a new shell process for each invocation. The following constraints must be met:

• Orchestrator will invoke a method you implement as def process(req):
• The input parameter req will always be a dictionary, following the same key names as the C# StepRequest class
• The method must return a dictionary serializable to JSON using json.dumps(resp)
• The Data property of the return dictionary must be a base64 string

Request and Response Dictionaries

The properties found within the input dictionary are identical to those found in the C# StepRequest class:

• GUID - unique identifier for the request
• Url - the URL on which the step was invoked
• Headers - a dictionary (NameValueCollection) containing the headers attached to the request
• Query - a dictionary (NameValueCollection) containing URL query elements
• Data - base64-encoded string containing the input data, should be decoded before use

The returned dictionary should use the same key names as found in the C# StepResponse class:

• Result - Success, Failure, Exception
• StatusCode - an HTTP status code (integer)
• ContentType - MIME type of the data within the Data property
• Data - base64-encoded string of the response data, your code must perform the encoding

Example

import base64

def process(req) -> dict:
    input_data = str(base64.b64decode(req["Data"]))
	print("Received " + input_data)
	resp = {} 
    resp["Result"] = "Success"
    resp["StatusCode"] = 200
    resp["ContentType"] = "text/plain"
    resp["Data"] = base64.b64encode(str.encode("You said " + input_data)).decode("utf-8")
    return resp