Is it possible to fetch a workflow variable through API?

[ccyen8358]

Hi,

I just read the document approval sample guide. In this guide we use the signalUrl function to get the url that triggers the Signaled Activity from client side (email in this case).

Is it possible to get this url through an api?
More broadly, is it possible to fetch any workflow variable through an api?

The reason I ask this question is because we want to embedded the "Signaled url" in our front-end SPA app instead of in the email link.

Sorry for taking up your time and thanks in advance.

[DavidPx]

The activity execution context lets you manipulate variables so I think you'd just set the signal URL like so:

using Elsa.Activities.Http.Extensions;
...
.Then(x =>
                {
                    var signalUrl = x.GenerateSignalUrl("foo");
                    x.SetVariable("mySignalUrl", signalUrl);
                })

And fetching variables from running workflows works great. Just get your WorkflowInstance from an IWorkflowInstanceStore and then hit up its Variables property. It has a typed Get method which takes the variable name.

[sfmskywalker]

That's a great way to generate a signal URL and reuse it later on. This also demonstrates the GenerateSignalUrl API exposed as an extension method on ActivityExecutionContext.

However, this is all Elsa 2 - in Elsa 1, the signal URL generation logic is not publically exposed unfortunately. However, there's no reason it couldn't be exposed, and I think we should do so in Elsa 2 for precisely the use case described by the OP.