private async Task StartWorkflowAsync(SigningRequest req, string[] signerEmails)
{
var model = new WorkflowStartModel
{
RequestId = req.Id,
DocumentName = req.DocumentName,
Message = req.Message,
SignerEmails = signerEmails,
Subject = req.Subject
};
string json = JsonSerializer.Serialize(model);
var startRequest = new HttpRequestMessage(HttpMethod.Post, _workflowStartUrl)
{
Content = new StringContent(json, Encoding.UTF8, "application/json")
};
HttpResponseMessage startResponse = await _httpClient.SendAsync(startRequest);
if (startResponse.StatusCode != System.Net.HttpStatusCode.Accepted)
{
throw new Exception("Unexpected start response: " + startResponse.StatusCode);
}
// Update info about the started workflow in DB
// Allows us to query status, terminate it etc.
DurableFunctionsCheckStatusResponse checkStatusResponse = JsonSerializer.Deserialize <DurableFunctionsCheckStatusResponse>(await startResponse.Content.ReadAsStringAsync());
req.Workflow.Id = checkStatusResponse.Id;
req.Workflow.StatusQueryUrl = checkStatusResponse.StatusQueryGetUri;
req.Workflow.SendEventUrl = checkStatusResponse.SendEventPostUri;
req.Workflow.TerminateUrl = checkStatusResponse.TerminatePostUri;
req.Workflow.PurgeHistoryUrl = checkStatusResponse.PurgeHistoryDeleteUri;
await _db.SaveChangesAsync();
}
public async Task <HttpResponseMessage> StartSigningWorkflow(
[HttpTrigger(AuthorizationLevel.Function, "post")] HttpRequestMessage req,
[DurableClient] IDurableOrchestrationClient starter,
ILogger log)
{
WorkflowStartModel request = await req.Content.ReadAsAsync <WorkflowStartModel>();
string instanceId = await starter.StartNewAsync(nameof(MainOrchestrator), request);
log.LogInformation("Started orchestration with ID '{InstanceId}'.", instanceId);
return(starter.CreateCheckStatusResponse(req, instanceId));
}
public async Task <SignerResult[]> MainOrchestrator(
[OrchestrationTrigger] IDurableOrchestrationContext context)
{
WorkflowStartModel request = context.GetInput <WorkflowStartModel>();
// Database update, has to be done in an activity
await context.CallActivityAsync(nameof(MarkWorkflowStarted), request.RequestId);
// there is also a variant that supports retries
// Prepare email send tasks
string[] signerEmails = request.SignerEmails;
var emailSendTasks = new List <Task>(signerEmails.Length);
for (int i = 0; i < signerEmails.Length; i++)
{
Task sendTask = context.CallActivityAsync(nameof(SendPleaseSignEmail), new EmailSendParameters
{
To = signerEmails[i],
Subject = request.Subject,
Message = request.Message,
RequestId = request.RequestId,
DocumentName = request.DocumentName
});
emailSendTasks.Add(sendTask);
}
// Fan out to send emails, activities triggered in parallel
await Task.WhenAll(emailSendTasks);
// Prepare parallel signing tasks
var signingTasks = new List <Task <SignerResult> >(signerEmails.Length);
for (int i = 0; i < signerEmails.Length; i++)
{
Task <SignerResult> signingTask = context.CallSubOrchestratorAsync <SignerResult>(nameof(WaitForSignature.WaitForSign), new WaitForSignParameters
{
SignerEmail = signerEmails[i],
RequestId = request.RequestId
});
signingTasks.Add(signingTask);
}
// Wait for result from each signer, another fan out
SignerResult[] results = await Task.WhenAll(signingTasks);
// Create signed document if everyone signed
if (results.All(r => r.Result == SigningDecision.Signed))
{
await context.CallActivityAsync(nameof(CreateSignedDocument), new CreateSignedDocumentParameters
{
RequestId = request.RequestId,
Results = results
});
}
// Send completion email to all signers
var completionEmailSendTasks = new List <Task>(signerEmails.Length);
for (int i = 0; i < signerEmails.Length; i++)
{
Task sendTask = context.CallActivityAsync(nameof(SendCompletionEmail), new SendCompletionEmailParameters
{
RequestId = request.RequestId,
To = signerEmails[i],
DocumentName = request.DocumentName
});
completionEmailSendTasks.Add(sendTask);
}
// Fan out to send completion emails
await Task.WhenAll(completionEmailSendTasks);
// Finally, mark the workflow completed in the DB
await context.CallActivityAsync(nameof(MarkWorkflowCompleted), request.RequestId);
return(results);
}
