Passing multiple selected objects from a Combo Box to a microflow after migrating to the React client

Issue

When migrating an application from the legacy client to the React client, the migration requires replacing the reference set selector widget with a Combo Box widget. In the original setup, the reference set selector allowed selecting multiple rows in an associated data grid, which is then passed as an argument to a microflow, triggered by a button.

After replacing the reference set selector with a Combo Box, the only variable available in the Combo Box configuration is the current object. There is no selection variable containing the list of selected objects to pass into the microflow. It is unclear whether this is a bug in the Combo Box widget or whether passing a multi-row selection into a microflow is unsupported by the Combo Box multi-select option.

Environment

Studio Pro v11.0.0 and newer

Combo Box v2.1.4 and newer

Cause

When converting a reference set selector (which is technically a grid) to a Combo Box, only the applicable configuration options are transferred, so grid-based selection behavior is not automatically carried over. However, passing a selected list of objects to a microflow is supported by the Combo Box when the correct data source and selection mode are configured.

Solution/Workaround

To make the selected objects available as a microflow argument when using a Combo Box, configure the widget as follows:

1. Set the Combo Box data source to Database.
2. Set the selection mode to Multi.
3. Once configured, the selection variable becomes available in the microflow settings of the button, allowing the selected objects to be passed as the microflow parameter.

Alternatively, a Data Grid 2 widget can be used, which also allows passing a selected subset of associated objects as arguments to a microflow via the action button.

Additional information

• Mendix documentation:
  • Combo Box
  • React Client
  • Data Grid 2