Adding a Custom Action to the Workflow Toolbox

Last modified: April 18, 2024

1 Introduction

You can expose a microflow as a workflow action and add it to the workflow toolbox. This is particularly useful if you plan to reuse the microflow logic several times, turning it into a custom workflow action is a good alternative to using the Call microflow action. There are the following advantages to having the custom workflow action:

  • It makes logic more reusable.
  • The workflow process is more visualized and understandable.
  • It saves you time: dragging and dropping a ready-to-use action is faster than configuring the Call microflow action.

This how-to teaches you how to do the following:

  • Call a microflow
  • Add microflow input parameters and return values
  • Expose the microflow as the workflow action

2 Prerequisites

Before starting this how-to, make sure you have completed the following prerequisites:

  • Familiarize yourself with workflow terms. For more information, see Workflows.
  • Install Atlas 3 from the Mendix Marketplace. As a result of installing Atlas 3, your app should contain the following modules that Workflow Commons depends on: Atlas_Core, Atlas_Web_Content, and DataGrid.
  • Your app has the following optional modules Workflow Commons and Mendix SSO modules for better developer experience. For more information on how to set up Workflow Commons in an existing app, see Adding a Workflow to an Existing App: Using Workflow Commons.

3 Exposing the Microflow as the Workflow Action

For example, you have the Employee Onboarding process set up in your app. You have an integration with the SAP system and have a microflow called ACT_SAP_INVENTORY_LAPTOP_CHECK that checks if the employee has a laptop already assigned to them and returns true or false value. To be able to reuse the logic of this microflow in the Employee_Onboarding workflow, you can expose this microflow as a workflow action.

However, as the best practice, Mendix recommends using a second microflow that will call the ACT_SAP_INVENTORY_LAPTOP_CHECK one. The benefits of using the second microflow are the following:

  • To make it easier to update parameters in ACT_SAP_INVENTORY_LAPTOP_CHECK. If you make changes in the parameters of the microflow that would mean that every task using this microflow will result in consistency errors. The calling microflow makes it possible to make changes to the parameters of the called microflow (ACT_SAP_INVENTORY_LAPTOP_CHECK) in the future, as you will have to modify only the calling microflow.
  • The calling microflow allows for data and parameter changes that the called microflow requires, but the workflow is not able to provide. For example, ACT_SAP_INVENTORY_LAPTOP_CHECK requires Employee ID, but the workflow has only Employee Name. You can get the Employee ID through the Employee’s record and pass this to the ACT_SAP_INVENTORY_LAPTOP_CHECK.
  • To have proper error handling, for example, you can validate what error has occurred and continue the workflow or abort it.

To create the calling microflow and add it as the custom action to the workflow toolbox, do the following:

  1. Create a new microflow that calls ACT_SAP_INVENTORY_LAPTOP_CHECK. Name the new microflow WFS_MY_SYSTEM_TASK.

  2. Make sure that the input parameters of the WFS_MY_SYSTEM_TASK microflow are mapped to the workflow definition. For the Employee_Onboarding workflow, add the EmployeeOnboarding parameter because the EmployeeOnboarding entity is set as the Workflow entity.

  3. In Toolbox, select Microflow call and drag it to the flow:

    Microflow call action
  4. Double-click the Microflow call activity to open its properties and set Microflow to ACT_SAP_INVENTORY_LAPTOP_CHECK.

  5. Click the End event and navigate to the Properties pane.

  6. Set the Return value for it to Boolean.

  7. Right-click the working area of the microflow and select Properties.

  8. In the Microflow properties dialog box, open the Expose as workflow action tab.

  9. Select the Expose as workflow action checkbox:

    Expose as Workflow Action
  10. The properties for the new workflow action appear. Do the following:

    1. Set the Caption to Inventory check: laptop.

    2. Set Category to Integration.

    3. Select an icon and a toolbox image from a disk for Icon and Image properties. For more information on properties, see the Expose as Workflow Action section in Microflow Properties.

      Expose as Workflow Action Settings
  11. Click OK.

Good job! You have configured the custom workflow action.

4 Using the Custom Action in Workflows

Now that you have exposed the microflow as the custom workflow action, you can use it directly from the workflow toolbox. Do the following:

  1. Open the Employee_Onboarding workflow.

  2. Open the Toolbox and find the newly created Integration category there > the Pass details to SAP action:

    Workflow Toolbox
  3. Drag the action into the workflow.

Congratulations! You have turned the microflow into the custom workflow action and can easily use it in the workflow editor.

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