Store Workflow Activity Data When Publishing - elsa-workflows

Question

I Need to store a specific activity data in another collection in database whenever a user publish a workflow in elsa.
I dont find any documentation, Please suggest me some resource or suggestion to achieve this. I have try to implement this with middleware. The Middleware code is
namespace WorkFlowV3
{
// You may need to install the Microsoft.AspNetCore.Http.Abstractions package into your project
public class CustomMiddleware
{
private readonly RequestDelegate _next;
static HttpClient client = new HttpClient();
public CustomMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task Invoke(HttpContext httpContext)
{
//Write Custom Logic Here....
client.BaseAddress = new Uri("#");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
string path = "/api/test-middleware-call";
HttpResponseMessage response = await client.GetAsync(path);
await _next(httpContext);
}
}
// Extension method used to add the middleware to the HTTP request pipeline.
public static class CustomMiddlewareExtensions
{
public static IApplicationBuilder UseCustomMiddleware(this IApplicationBuilder builder)
{
return builder.UseMiddleware<CustomMiddleware>();
}
}
}
But in this process, I cant fetch the specific activity data.

Answer 1

The easiest way to store information in your own DB in response to the "workflow published" event is by implementing a notification handler (from MediatR) that handles the WorkflowDefinitionPublished notification.
For example:
public class MyWorkflowPublishedhandler : INotificationhandler<WorkflowDefinitionPublished>
{
private readonly IMyDatabaseStore _someRepository;
public MyWorkflowPublishedhandler(IMyDatabaseStore someRepository)
{
_someRepository = someRepository;
}
public async Task Handle(WorkflowDefinitionPublished notification, CancellationToken cancellationToken)
{
var workflowDefinition = notification.WorkflowDefinition;
// Your logic to do a thing.
}
}
To register this handler, from your Startup or Program class, add the following code:
services.AddNotificationHandler<MyWorkflowPublishedhandler>();
Your handler will be invoked every time a workflow gets published.