Why does the workflow need a httpcontext?

[weirdyang]

I'm trying to trigger a workflow using a message from a kafka queue, but it fails at the log task:

"An unhandled error occurred while executing an activity. Workflow ID: '18'. Activity: '4mexqzdhk7tpj055nckpytq1dm', 'LogTask'. 
Putting the workflow in the faulted state.", "callSite": "OrchardCore.Workflows.Services.WorkflowManager.ExecuteWorkflowAsync", "exception": "Value cannot be null. (Parameter 'httpContext')", "stacktrace": "   
at Microsoft.AspNetCore.Mvc.ActionContext..ctor(HttpContext httpContext, RouteData routeData, ActionDescriptor actionDescriptor, ModelStateDictionary modelState)\r\n 
  at OrchardCore.DisplayManagement.Liquid.LiquidViewTemplateExtensions.GetActionContextAsync(HttpContext httpContext)\r\n 
  at OrchardCore.DisplayManagement.Liquid.LiquidViewTemplateExtensions.GetViewContextAsync(LiquidTemplateContext context)\r\n  
 at OrchardCore.DisplayManagement.Liquid.LiquidViewTemplateExtensions.RenderAsync(LiquidViewTemplate template, TextEncoder encoder, LiquidTemplateContext context, Object model)\r\n  
 at OrchardCore.Workflows.Expressions.LiquidWorkflowExpressionEvaluator.EvaluateAsync[T](WorkflowExpression`1 expression, WorkflowExecutionContext workflowContext, TextEncoder encoder)\r\n 
  at OrchardCore.Workflows.Activities.LogTask.ExecuteAsync(WorkflowExecutionContext workflowContext, ActivityContext activityContext)\r\n   
at OrchardCore.Workflows.Services.WorkflowManager.ExecuteWorkflowAsync(WorkflowExecutionContext workflowContext, ActivityRecord activity)" }

OrchardCore/src/OrchardCore/OrchardCore.DisplayManagement.Liquid/LiquidViewTemplate.cs

Line 188 in 6911193

public static async Task<ViewContext> GetViewContextAsync(LiquidTemplateContext context)

Why does the log task need a httpcontext? is it because of liquid? if so, how do I get around this?

[weirdyang]

                using (ShellScope shellScope = await _shellHost.GetScopeAsync("Default"))
                {
                    await shellScope.UsingAsync(async scope =>
                    {
                        if (scope != null)
                        {
                            _httpContextAccessor.HttpContext = scope.ShellContext.CreateHttpContext();
                            IWorkflowManager manager = scope.ServiceProvider.GetRequiredService<IWorkflowManager>();
                            var messageData = new Dictionary<string, object>
                        {
                            { "value", cr.Message.Value is null ? "" : cr.Message.Value.ToString() },
                            { "key", cr.Message.Key is null ? "" : cr.Message.Key.ToString() },
                            { "topic", cr.Topic }
                        };
                            await manager
                                .TriggerEventAsync("EVENTNAME", messageData);
                        }
                    });
                }

I ended up doing something like this to add the httpcontext, will there be any issues?

[Piedone]

I think this is fine.

Yes, the context is needed to evaluate the Liquid log message.

[weirdyang]

thanks!