ASP.NET based Workflow Engine

asp.networkflow

I am working on a design spec for a new application that will be heavily workflow driven.

Before I re-invent the wheel, is there a decent lightweight workflow engine that plugs into ASP.NET already around?

Basically, I'm looking for something that handles moving through a defined set of workflow pages while handling state management automatically.

If this isn't around already, I'll definitely try to abstract the engine from my app and put it on codeplex, as it would be really handy.

Any suggestions?

Note: .NET 2.0, so no WWF, though I think WWF is overkill for my needs.

EDIT: Seems like there is a legitimate need for this, and there isn't a product out there…So I might build this.

Here is what I'm picturing:

Custom Page class called WebFlowPage
All WebFlowPage's are registered in a Workflow mapper.
Each WebFlowPage has some form of state object.
A HttpHandler handles picking the appropriate WebFlowPage based upon the workflow, and populating it from the state object.

Best Answer

Is the workflow dynamic, or static?

If the workflows are simple, you could roll your own workflow engine. In certain situations, it can be fairly simple, and just a couple of data tables to handle the rules, processing and state.

Alot of workflow engines are built for large scale processing (credit card applications, for example). For small scale, you should at least consider your own, which would eliminate the overhead and dependency of/on an engine.

Related Solutions

Asp.net-mvc – Compile Views in ASP.NET MVC

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

Open the project file in a text editor.
Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>

C# – How to create a dropdownlist from an enum in ASP.NET MVC

For MVC v5.1 use Html.EnumDropDownListFor

@Html.EnumDropDownListFor(
    x => x.YourEnumField,
    "Select My Type", 
    new { @class = "form-control" })

For MVC v5 use EnumHelper

@Html.DropDownList("MyType", 
   EnumHelper.GetSelectList(typeof(MyType)) , 
   "Select My Type", 
   new { @class = "form-control" })

For MVC 5 and lower

I rolled Rune's answer into an extension method:

namespace MyApp.Common
{
    public static class MyExtensions{
        public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                select new { Id = e, Name = e.ToString() };
            return new SelectList(values, "Id", "Name", enumObj);
        }
    }
}

This allows you to write:

ViewData["taskStatus"] = task.Status.ToSelectList();

by using MyApp.Common