Workflow Engine: Release Notes


  • Designer usability improvement. Transition info will now be displayed in a fuller, more comprehensive form. You can now switch between full screen and normal edit window display modes. Toolbars design has been changed.
  • you can customize Activity и Transition rendering in the Designer.
  • you can customize Designer windows.
  • Designer performance has been optimized.
  • Scheme inlining. Now you can check a scheme as a scheme that can be inlined and embed it into another scheme. Thus you can re-use typical parts of your processes many times, without copying them between schemes. Multi-layered inlining is supported.
  • Process Info window has been added into the specific process view mode. It allows you to view this process parameters, transition history, launched timers. Here full information on subprocesses is also displayed.
  • You can specify annotations for Activity and Transition. Annotations are a dictionary (key - value) which you can set in the Designer individually for each Activity ot Transition. You can read annotation value in the code, using the following methods: activityDefinition.GetAnnotation<T>(name), transitionDefinition.GetAnnotation<T>(name), processInstance.ProcessScheme.GetActivityAnnotation<T>(activityName, name), processInstance.ProcessScheme.GetTransitionAnnotation<T>(transitionName, name)
  • For the string parameter, which is transferred into Actions, Conditions and Rules, you can specify the structure which will define the form in which this parameter will be displayed in edit mode in the Designer. Form field contents can be specified in the Designer in the CodeActions section. Or you can create a class implementing IDesignerParameterFormatProvider interface on the server and configure your WorkflowRuntime in the following way: workflowRuntime.WithDesignerParameterFormatProvider(new YourDesignerParameterFormatProvider()). Thus you can specify the appearance of the string parameter which is transferred into Action, Condition or Rule.
  • In the event handler workflowRuntime.OnWorkflowError you can now cancel exception throwing, using event arguments args.SuppressThrow = true;. Also you can specify the Activity, which will be set after error processing. For example, it can be initial activity: args.ActivityToSet = args.ProcessInstance.ProcessScheme.InitialActivity;
  • For simple execution of complex business cases in WorkflowRuntime use two of the following methods: workflowRuntime.GetAvailableCommandsWithConditionCheck(...) - get the list of available commands with additional conditions check, and workflowRuntime.ExecuteCommandWithRestrictionCheck(...) - execution of the command with additional restrictions check.
  • Correct merging of the subprocess и parent process has been added, when a subprocess is merged with its parent process immediately after launch. In other words, if a subprocess contains only Auto triggered transitions. Now merge will be correct, and the subprocess will wait till the parent process is unlocked.
  • Process execution can be cancelled using CancellationToken. Such cancellation will be activated automatically if you configure your WorkflowRuntime in the following way: workflowRuntime.SetCancellationTokenHandling(CancellationTokenHandling.Throw).

The following additional actions must be taken to upgrade to Workflow Engine 4.0:

  • Don't forget to update packages or dlls, and the Designer javascript, css and all designer related images.
  • Run the SQL script update_4_0.sql for all relative databases. You will find this script in your provider's archive.
  • If you have used process status change (for example args.ProcessStatus = ProcessStatus.Idled;) to cancel exception release after the event has been processed workflowRuntime.OnWorkflowError, you will need to use the following code args.SuppressThrow = true;. Status change hack won't work, custom status will be installed, but the exception will still be thrown.


  • Moving the canvas (in the Move mode) with arrows was added to the designer.
  • Explicit passing of CultureInfo was added to methods GetInitialCommands, GetInitialState, GetCurrentState and GetAvailableCommands of the WorkflowRuntime class
  • Full samples (Vacation request approval) for all supported databases for ASP.NET Core and ASP.NET MVC. Full samples for MSSQL, Postgres and Oracle database for Web Forms.


  • Added automatic size increase for background in designer.
  • Added designer localization files for German, French, Spanish, Italian, Portuguese, Turkish, and Russian languages.
  • .NET Core NuGet packages come with .NET Standard 1.6 and .NET Standard 2.0 libraries. This allows you to use these packages with any .NET Core version, including 2.1.
  • The OptimaJet.Workflow.Core.Logging.ILogger interface was added; it can be initializes with your own logger in the WorkflowRuntime object. It is used to integrate with the Workflow Server logging system, but you can use it to integrate with your own system. Bear in mind that the logger in the WorkflowRuntime object is not initialized by anything by default.


  • MongoDB provider for Workflow Engine .NET Core was added.
  • MongoDB driver was updated to version 2.7. You can now connect to CosmosDB through a MongoDB connection.
  • The following hotkeys were added to the Workflow Designer:
    • Ctrl + A - Select all
    • Ctrl + C - Copy selected items
    • Ctrl + E - New Activity
    • Ctrl + I - Extended info
    • Ctrl + Y - Redo
    • Ctrl + Z - Undo
    • Arrows - Move selected items
    • Delete - Delete
    • Alt + Enter - Full-screen mode
    • Ctrl + M - Move mode

The following additional actions must be taken to upgrade to Workflow Engine 3.3 if you are using MongoDB:

  • Only for MongoDB users: it is necessary to apply the _update_3_2_to_33.js script to your database.


  • Added providers for MySQL and Oracle, running under .NET Core
  • Added class AggregatingRuleProvider, designed to combine several IWorkflowRuleProvider into one IWorkflowRuleProvider.
  • Added class AggregatingActionProvider, designed to combine several IWorkflowActionProvider into one IWorkflowActionProvider.


  • Workflow Engine's relational database storage system has been optimized. Additional indices have been built; obsolete indices have been removed; the size of some columns has been changed. Generally, these changes should result in the improvement of Workflow Engine's performance, especially for Microsoft SQL Server. All these changes have already been included into installation scripts; use the _update_31.sql script to update the existing databases.
  • BulkCreateInstance now works for Microsoft SQL Server and .NET Core (version >= 2).


The _update_31.sql script contains a change of index and size of certain columns. Be particularly careful when applying it to the production database.


  • The interface of Workflow Designer has been revamped to improve usability
    • The look and feel of the scheme has been changed
    • The library that renders popup windows and controls has been changed from jQuery UI to Semantic-UI. jQuery UI has been removed from the project completely. Autocomplete for lists has been implemented with jQuery-autoComplete
    • The Konva.js version has been updated to 2.0.2
    • The 'Extended Info' mode has been added to provide additional information needed when creating a workflow scheme
    • Undo and redo have been added
    • Current activity of subprocesses is now highlighted
    • Global CodeActions have been simplified
    • Scheme legend has been added
  • Builds for .NET Core 2.0 and .NET Standard 2.0 have been included to .NET Core packages
  • The order of search for Action, Condition and Rule in Code Actions and IWorkflowActionProvider(IWorkflowRuleProvider) has been changed. Earlier on, the order was as follows (highest to lowest priority): Global CodeAction, CodeAction in the scheme, IWorkflowActionProvider(IWorkflowRuleProvider). Now this order is the following by default: CodeAction in the scheme, Global CodeAction, IWorkflowActionProvider(IWorkflowRuleProvider). Thus, CodeAction in the scheme has the highest priority. Search priority can be set with the runtime.SetExecutionSearchOrder(ExecutionSearchOrder order) setting.
  • Parameter type names used to be stored as an assembly qualified name (by specifying the version of the build and the public key token), which resulted in troubles when migrating schemes from the .NET Framework environment to the .NET Core environment. Now a simplified type name - the one that is displayed in Designer - is stored in the scheme. Old schemes are loaded without changes; type names will be replaced after the first save of the scheme in the Designer.
  • Errors that occur when there's a '-' in CodeAction names have been fixed.

The following additional actions must be taken to uprgade to Workflow Engine 3.0:

  • It is not necessary to update to the new version of the Designer; however, we strongly advise it. The old version of the Designer shall work with the new versions of the Workflow Engine at least within the next half a year. If you are updating to the new version of the Designer, introduce the following changes to the pages where Designer is displayed.
    • Delete links to jquery-ui.min.css and jquery-ui.js
          <link href="/Content/themes/base/jquery-ui.min.css" rel="stylesheet" type="text/css"/>
          <script src="/Scripts/jquery-ui.js" type="text/javascript"/>
    • Add links to semantic.min.css, semantic.min.js,
          <link href="/Content/semantic.min.css" rel="stylesheet" type="text/css"/>
          <script src="/Scripts/semantic.min.js" type="text/javascript"/>
          <script src="/Scripts/" type="text/javascript"/>
  • If the new order of search for Action, Condition and Rule does not suit you, change it with the following setting:
runtime = runtime.SetExecutionSearchOrder(ExecutionSearchOrder.GlobalLocalProvider);

Then, everything shall work the same way it did in the previous versions.

  • Workflow Engine's reaction to the scenario where it could not find an Action, Condition or Rule in CodeActions or IWorkflowActionProvider(IWorkflowRuleProvider) has been changed. Earlier on, Workflow Engine ignored this scenario which made it difficult to debug schemes. Now, the NotImplementedException exception is thrown, specifying the name of the object which was not found. If this behavior does not suit you, use the following setting:
runtime = runtime.SetIgnoreMissingExecutionItems(true);


  • A 'Refresh' button and its functionality have been added to Designer
  • A 'Full Screen' button and its functionality have been added to Designer
  • BulkCreateInstance and TimerManager performance has been enhanced
  • Scroll-based scaling has been added to Designer


  • Now it is possible to create asynchronous Actions and Conditions. You can call asynchronous methods from Actions and Conditions using the await keyword. Such methods will be the most effective if you use asynchronous methods of the WorkflowRuntime object, for example, ExecuteCommandAsync instead of ExecuteCommand, or SetStateAsync instead of SetState, etc. You can create asynchronous Actions in Designer. To do that you simply need to check the Async checkbox in the Action or Condition where you're going to call asynchronous methods from. If you use IWorkflowActionProvider, then you will need to implement 4 additional methods. bool IsActionAsync(string name) and bool IsConditionAsync(string name) should return true so that the Action or Condition are called asynchronously. The execution of an asynchronous Action or Condition is done in the Task ExecuteActionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token) and Task<bool> ExecuteConditionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token) methods.
  • Parameters conveyed to the process with the command no longer need to be described as command parameters. Iа such a parameter is described in the scheme, it will be a Temporary or a Persistence one, depending on which Purpose is specified in the scheme. If the parameter is not described in the scheme, it will be a Temporary one.
  • The ExecuteCommand and ExecuteCommandAsync methods return information on whether the command has been executed (it may not be executed under certain conditions) and the ProcessInstance state after the execution of a command.

The following additional actions must be taken to uprgade to Workflow Engine 2.2:

  • If you use IWorkflowActionProvider, you will need to add 4 new methods to it: IsActionAsync, IsConditionAsync, ExecuteActionAsync, ExecuteConditionAsync. If you do not yet intend to use asynchronous Actions, then the IsActionAsync and IsConditionAsync methods should always return false, whereas ExecuteActionAsync and ExecuteConditionAsync can throw a NotImplementedException.
public bool IsActionAsync(string name)
    return false;

public bool IsConditionAsync(string name)
    return false;

public async Task ExecuteActionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token)
    throw new NotImplementedException();

 public async Task<bool> ExecuteConditionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token)
    throw new NotImplementedException();


  • Workflow Engine for .NET Core App 1.1 is released. All Workflow Engine functions are supported. This version will be updated simultaneously along the .NET Framework version. 2 persistence providers are currently supported: MS SQL Server and PostgreSQL. Links to NuGet packages and samples can be found here.
  • Workflow Engine scheme import/export to/from BPMN2 has been added.
  • Bulk process creation has been added. Now you can create a large amount of processes (100 - 100,000) in significantly less time than when using the CreateInstance method. Use the _runtime.BulkCreateInstance(..) method to do that. Currently, the feature is available in the .NET Framework version of Workflow Engine and supports only MS SQL Server. The list of supported databases will be expanded.


  • Designer UI has been improved, transitions are now linear for better usability
  • Scheme rendering library KineticJS has been replaced with Konva.js
  • WorkflowDesigner.readonlymode(), WorkflowDesigner.printablemode() and WorkflowDesigner.ediatblemode() methods have been added to WorkflowDesigner object in the client. readonlymode makes Designer uneditable. printablemode removes the toolbar, the grid and all controls, zooming designer so that the scheme occupies the entire canvas. This mode can be used to print Designer's viewport to a PDF within a browser. editablemode makes Designer editable.
  • Designer now allows users to make an autocomplete list for the following fields: Actor.Value, Activity.Implementation.Action parameter, Transition.Condition.ActionParameter. The autocomplete list is being populated server-side via the IDesignerAutocompleteProvider interface and by transferring implementation to the WorkflowRuntime object via _runtime.WithDesignerAutocompleteProvider(provider).
  • The GetConditions method has been added to the IWorkflowActionProvider interface. Now, the choice of conditions and actions in Designer can be split.
  • Parameters of any type not mentioned in the scheme can now be used in Actions' code. The type should be serialized in JSON. Three methods are available: _processInstance.SetParameter("parameterName",parameterValue,ParameterPurpose.Persistence), _processInstance.GetParameter<ParameterType>("parameterName") and _processInstance.RemoveParameter("parameterName").
  • Ability to create Timers with a value which is undefined at the time of creation of a process has been added. Timer.Value == -1 means that the current transition will not be executed until the respective timer has a defined value. Timer.Value == 0 means that in case the timer connected to a transition does not have a value, this transition shall be processed automatically. Initial value of a timer can be set with the _runtime.NeedTimerValue event.
  • Ability to modify execution time for timers in running processes has been added. Use methods _runtime.SetTimerValue(processId,timerName,newValue) and _runtime.ResetTimerValue(processId, timerName) to change and reset timer values outside the process. Use methods _runtime.SetTimerValue(processInstance,timerName,newValue) and _runtime.ResetTimerValue(processInstance, timerName) to change and reset timer values from within your Actions.
  • Newtonsoft.Json version has been changed from 7.0.1 to 9.0.0.

The following additional actions must be taken to uprgade to Workflow Engine 2.0:

  • Replace the link to KineticJS with the link to konva.min.js. Konva.js library is included in the ZIP archive and in nuget package WorkflowEngine.NET-Designer.
  • Update Newtonsoft.Json.dll to 9.0.0. The library is included in the ZIP archive and in nuget package WorkflowEngine.NET-Core.
  • If you use implementation of IWorkflowActionProvider you should add a public List<string> GetConditions() method to it. It is advisable that the GetActions returns only the list of available Actions, whereas the GetConditions method should return the list of available Conditions. In this case they should be filtered properly in the Designer. However, if you do not want to modify your code, make sure that the GetConditions method throws a NotImplementedException. In this case, everything should work as it used to.
  • IF you use Oracle, you should run an update_1_5_to_2_0.sql script from the Oracle provider ZIP archive or a NuGet package.


  • Two new persistence providers were added to WorkflowEngine.NET Redis Provider for Redis and Ignite Provider for Apache Ignite
  • notrendertoolbar property was added to the Designer object configuration (client side javascript). You can hide toobar in the workflow designer for end users.
  • Second parameter which allow ignore AutoSchemeUpdate sign of Activity was added to the WorkflowRuntime.UpdateSchemeIfObsolete method.
  • Several redundat operations related to subprocess features were removed to increase performance.
  • Conditions are checked for transitions that creating subprocesses.


In this release several features have been added to simplify the generation of forms based on commands.

  • The sign IsRequired for command parameter. You can take it into account when generating forms, also it is used in the command validation before the execution of command.
  • The Default value for command parameter. You can access it using CommandParameter.DefaultValue property, after you have received the list of available commands. You can set all command parameters to default value using WorkflowCommand.SetAllParametersToDefault or WorkflowCommand.SetParameterToDefault functions. The Default value must be a valid JSON (wich can be deserialized to type which is specified in the bond Parameter) or will be interpreted as a string.
  • An autocompete was added in the field Type of Parameter (editing window Parameters). It makes a suugestions about types which can be used such as primitive types (Int32, String etc) or your custom types. Types from assemblies which was registerd using _runtime.RegisterAssemblyForCodeActions function are added in the autocomplete list. To prevent registration or filter the list you can use the last two optional parameters of _runtime.RegisterAssemblyForCodeActions function - ignoreForDesigner and designerTypeFilter.
  • The Initial values were added for Parameters. You can yse Initial value only for Parameters which have Purpose = Persistence. This values must be a valid JSON (wich can be deserialized to type which is specified in the bond Parameter) or will be interpreted as a string. These values will be set to the process when it is created.
  • The JSON editor was added for edit Parameter.InitialValue (Parameters window), Command.InputParameters.DefaultValue (Commands window), Actor.Value (Actors window), Activity.Implementation.ActionParameter (Activity window), Transition.Condition.ActionParameter (Transition window). The JSON editor includes a syntax highlight and Format button. The Format button can be used to format your JSON. Please note that if you use JSON with unquoted property names, you must add reference on json5.js library on Designer page. For Parameter.InitialValue (Parameters window) and Command.InputParameters.DefaultValue (Commands window) the JSON editor aso includes Create button. This button can be used to create an empty object based on Parameter.Type. Designer (on server) uses only parameterless constructor to create the empty object.
  • There are two new events was added to WorkflowRuntime. Both are occured only in normal execution mode (not in pre-execution). BeforeActivityExecution - is occured after the Runtime has chosen an appropriate transition for execution but before Actions in an Activity were executed. ProcessActivityChanged - is occured after some Activity was executed. You can use ProcessActivityChanged.TransitionalProcessWasCompleted property to ensure that the command (or timer) execution was finished. Using of these events could be more convenient than ProcessStatusChanged in some cases.
  • GetAllActorsForCommandTransitions(ProcessInstance) method was added to WorkflowRuntime. You can use this method to get next potential approvers for current state.
  • You can change the JSON Serializer settings for Parameters derialization using SetParameterSerializerSettings configuration method.


  • Schema was added in constructors of all SQL providers. For MsSQL the default schema is "dbo". For PostgreSql the default schema is "public". For Oracle the default schema is null.
  • You are able to specify an interval timer value with milliseconds, seconds, minutes and days. For example "1d 2h 4m 30s" - one day two hours four minutes thirty seconds or "5m 30s", "14d", "12h", "10m", "10s" etc. You are able to use following names. d, day or days to specify interval in days. h, hour or hours to specify interval in hours. m, minute or minutes to specify interval in minutes. s, second or seconds to specify interval in seconds. ms, millisecond or milliseconds to specify interval in milliseconds. If the interval is specified as just a numeric value, it is interpreted as the interval in milliseconds.
  • You are able to pass initial parameters of a process by using _runtime.CreateInstance(CreateInstanceParams createInstanceParams) method. Parameters passed in the createInstanceParams.InitialProcessParameters property will be used as initial for parameters of a process.


  • The JSON serializer used by the engine was changed from ServiceStack.Text to Newtonsoft.JSON. 1.5.3 version of WFE was built with the verion 7.0 of Newtonsoft.JSON.
  • MSSQL provider was rewritten from LINQtoSQL to ordinary SQL queries.
  • The Parameter window in the designer was implroved. Now you can hide System parameters. They are hidden by default.
  • Working with types in the Parameter window in the designer was improved. Now you are able to use short type's names such as String, Guid, Int32 etc for primitive types. The type names including namespace for custom types (OptimaJet.Workflow.Core.Model.ActivityDefinition, Business.Approvers etc)- Also you are able to use <> for generic types and [] for arrays.
  • Fixed a bug in the timers for their correct restart after restart of the workflow runtime.


  • ExecutedActivity and ExecutedTransition properties added in ProcessInstance class. Via them, you can access executed transition and activity during a transitional process.
  • A scheme of a process downloaded from the designer with not ecoded Code Actions. You can upload a scheme with encoded or not encoded code actions.
  • The algorithm of sub-process scheme separation improved for it to work properly with the different schemes.
  • GetAvailableCommands method returns distinct commands.
  • Fixed parsing of the values of the Timers in different cultures
  • While merging the processes you can access the parameters of a subprocess using the property MergedSubprocessParameters of the ProcessInstance class.