Workflow Engine 5.0

October 7, 2020

Designer

• Designer windows have been reworked to behave as non-modal which allows:
  • to keep them open while working with a scheme.
  • to open multiple windows, change their size and behavior.
• Customization of Designer windows is now simplified; each window is represented by a Vue.js template which can be now altered independently from the rest of the Designer.
• Customization of Designer toolbars simplified.
• A Designer library of typical schemes added which represent most frequently used blocks which can be dragged onto your schemas.
• A library of custom activities added; these are single action activities whose settings are adjustable within the form.
• Forms to edit properties of activities and transitions now have two viewing modes - Default and Expert. The Default mode represents only the essential and most used settings, while the Expert mode combines all the settings.

Sub-processes

• Sub-processes can now be launched in a separate thread to allow for physical parallelism at the scheme level.
• Methods to copy parameters into a sub-process can now be carried out using the following options:
  • copy all parameters (default option, previously available)
  • not to copy parameters
  • only copy specified parameters
  • ignore specified parameters.
• New feature to specify a method to transfer sub-process parameters on to its parent process when merging. The following options are available:
  • transfer only the parameters absent in the parent process (default option, previously available)
  • transfer all parameters
  • only copy indicated parameters
  • ignore indicated parameters.
• New feature to clearly indicate whether a particular transition starts a sub-process or finalizes it; previously identified automatically, the transition can be now obviously set.
• New feature to specify a sub-process name which can be represented as a simple string or a calculated expression; expressions can consume parameters (this is syntactically similar to conditional expressions). In this way, new sub-processes can be created simply by changing parameter values used when a sub-process name is generated. As an example, consider creating an invoice approval scheme where the invoice will contain several product items. It is now possible to design a scheme in which approval of the items will be represented by a sub-process. Furthermore, by combining loops (in the plugin) and sub-process naming calculations a sub-process for each product item can be created.
• New feature to specify a sub-process id, or calculate it based on the parameters; herein, substitutions are used - not expressions.

Persistence Providers

• All persistence providers are implemented as completely asynchronous. As a result, the Workflow Engine core operates in a completely asynchronous fashion suitable for scalability.
• .NET Core provider for MsSql utilizes Microsoft.Data.SqlClient instead of System.Data.SqlClient.

Workflow Runtime

• Method Resume is added to API Workflow Runtime. Contrary to the SetState method, it does not execute a current activity, or a set one, but rather attempts to continue execution of the process. This method can be used to go on with a process execution after a failure, or in the case of changes in external conditions.
• Restorer Restore Decision Resume added.
• New in the ProcessInstance class:
  • Indexer for getting and setting parameter values
  • Methods to manipulate root process parameters from within a sub-process.
  • For all standard events, now exist their asynchronous counterparts.

Plugins

• FTP and SFTP support added to the File Plugin. Attention. File Plugin is supplied as a separate Nuget package/dll
• New plugin, Loops Plugin, added for simple implementation of the for and foreach.
• Within the action BasicPlugin.HttpRequest you can specify the name of the parameter which is to hold the result.
• Within the action BasicPlugin.SetParameter, and the BasicPlugin.CheckParameter condition, you can set and verify the root process' parameters.
• Many new conditions added to BasicPlugin.CheckParameter and BasicPlugin.CheckHTTPRequest.
• New plugins added for interaction with Slack, Telegram, Twilio, Nexmo are provided as Nuget packages (dlls).

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 5.0:

• Warning. If using Redis, please, contact our support for update instructions.

• Run the SQL script update_4_2_to_5_0 for all relative databases and MongoDB.

  • MSSQL
  • PostgreSQL
  • Oracle
  • MySQL
  • MongoDB

• Update all files related to the Designer. They are available here.

• Be mindful, that these files must be linked to the designer page:

  • workflowdesigner.min.css
  • workflowdesigner.min.js
  • jquery

  All the other javascript libraries previously required, do not need a separate attachment for they are now compiled inside workflowdesigner.min.js.

• Pay attention to the new way of initializating a WorkflowDesigner object instance.

  wfdesigner = new WorkflowDesigner({
    name: 'simpledesigner',
    apiurl: '/Designer/API',
    renderTo: 'wfdesigner',
    templatefolder: '/templates/',
    graphwidth: graphwidth,
    graphheight: graphheight
  });
  • Indicating the path to the images folder is no longer required and the folder can be deleted.
  • Yet, the path to the templates folder must be specified as it contains templates for all the forms and the library of schemes.
  • It is advised to reimplement WorkflowDesigner initializations, as is shown here.

• If you are using .NET Framework you may need to use Request.Unvalidated[key] instead of context.Request.Form[key] in the DesignerController.cs.

• Attention. Event handlers OnSchemaWasChanged and OnSchemaWasChangedAsync are now initialized inside a locked process. That is, prior to releasing the Running status. The code, as described in the documentation will continue to work as expected without need to change it. Yet, if SetActivityWithoutExecution[Async] or SetActivityWithExecution[Async] are called in these handlers, it should be done using this flag doNotSetRunningStatus = true. In turn, if you utilized methods ExecuteCommand, SetState and similar, be aware that there methods which lock the process. Therefore, is might be best to use methods: SetActivityWithoutExecution[Async] or SetActivityWithExecution[Async]. If you have implemented a complicated logic for updating schemes which leads to a failed attempt at updating you the Workflow Engine version because of this change, reach us at support@optimajet.com, and we'll help you.