designer support to create custom activity based on the same switch functionality

[diego-034]

I want to be able to create different custom activities with the same switch functionality and additionally other fields and configurations for a specific problem, in the configuration part it works fine.

But when it comes to seeing the cases or as options in the designer to be able to decide what to do in each case, it is not shown, it may be configurations, in that case if possible I would like to know how the switch was configured to be able to show the option branches in the designer.

Initial configuration

 services.AddElsa(elsa => elsa
                    .UseMongoDbPersistence<ElsaMongoDbContext>(
                    options => options.ConnectionString = mongoDbConnectionString)
                    .AddConsoleActivities()
                    .AddHttpActivities(elsaSection.GetSection("Server").Bind)
                    .AddJavaScriptActivities()
                    .AddEmailActivities(elsaSection.GetSection("Smtp").Bind)
                    .AddQuartzTemporalActivities()
                    .AddActivity<AnswerTree>()
                );

Custom Activity

[Trigger(
       Category = "N5 CTA",
       DisplayName = "AnswerTree",
       Description = "Create a AnswerTree",
       Outcomes = new[] { OutcomeNames.Default }
   )]
    public class AnswerTree : Activity, INotificationHandler<ScopeEvicted>
    {

        [ActivityProperty(Hint = "The conditions to evaluate.", UIHint = "switch-case-builder", DefaultSyntax = "Switch")]
        public ICollection<SwitchCase> Cases { get; set; } = new List<SwitchCase>();

        [ActivityProperty(
            Hint = "The switch mode determines whether the first match should be scheduled, or all matches.",
            DefaultValue = SwitchMode.MatchFirst,
            SupportedSyntaxes = new[] { SyntaxNames.Literal, SyntaxNames.JavaScript, SyntaxNames.Liquid }
        )]

        public SwitchMode Mode { get; set; } = SwitchMode.MatchFirst;

        [ActivityProperty(
            UIHint = ActivityPropertyUIHints.SingleLine,
            Hint = "Nombre del Answer Tree (AT/name of flow)")]
        public string _title { get; set; }

        public bool EnteredScope
        {
            get => GetState<bool>();
            set => SetState(value);
        }
        protected override IActivityExecutionResult OnExecute(ActivityExecutionContext context)
        {
            if (!context.WorkflowInstance.Scopes.Contains(x => x.ActivityId == Id))
            {
                if (!EnteredScope)
                {
                    context.CreateScope();
                    EnteredScope = true;
                }
                else
                {
                    EnteredScope = false;
                    return Done();
                }
            }

            var matches = Cases.Where(x => x.Condition).Select(x => x.Name).ToList();
            var hasAnyMatches = matches.Any();
            var results = Mode == SwitchMode.MatchFirst ? hasAnyMatches ? new[] { matches.First() } : new string[0] : matches.ToArray();
            var outcomes = hasAnyMatches ? results : new[] { OutcomeNames.Default };

            return Outcomes(outcomes);
        }

        Task INotificationHandler<ScopeEvicted>.Handle(ScopeEvicted notification, CancellationToken cancellationToken)
        {
            if (notification.EvictedScope.Type != nameof(AnswerTree))
                return Task.CompletedTask;

            var data = notification.WorkflowExecutionContext.WorkflowInstance.ActivityData.GetItem(notification.EvictedScope.Id, () => new JObject());
            data.SetState(nameof(EnteredScope), false);
            data.SetState("Unwinding", false);

            return Task.CompletedTask;
        }
    }

[sfmskywalker]

Nice. The only thing missing it seems is a designer plugin for your custom activity. The reason the branches work for the Switch activity is because the designer has a plugin called SwitchPlugin.

You would basically need a copy of that and just rename certain parts to match your activity.

Being able to extend the designer with your own plugins like this should be supported but it's not yet documented, or even tried out (from my end at least). But @tomy2105 happened to have created a nice issue that we could extend to also enable creating & registering custom plugins.

[sfmskywalker]

A recent change now allows you to do exactly what you are looking for. Please try it out. Should you still run into any issues with this, please create a new issue or reopen this one.