Problem with dropdown select - outsystems traditional web

Hi There,

I am developing a web application in OutSystems 11 web platform.

I used dropdown select for the dropdown below.

When I do ajax refresh of parent div, It says error like this.

Rank: #97

Hi Aravind M,

The Dropdown Select widget requires a Boolean to hold the values of the selection.

You will have to add a Boolean computed field on the list / query on the combo.


In the screenshot I shared, since the Boolean is False for all, the DropDown will start with no records selected.

Best regards,


Rank: #97

Hi Aravam M,

Just to make sure, you are trying to achieve this, right?

This is the Live Style Guide of OutSystems UI for Traditional Web which shows the patterns available and how to use it and you can download the code here.

In any case, for the Dropdown Select this is how it is applied.

1. Have the query or list you want as the source for the widget, in the example GetEmployees on Preparation:

2. Set them as source of the combobox and have an id for it (in this case dropdown). Take into account that the variable DropdownSelect will hold the selected value.

3. Add the Dropdown Select widget right after the combobox with the widget id set to the combobox id (in my example dropdown.id)

I hope it helps.

Best regards,


Rank: #97

Now I understood your issue.

This widget is using javascript which hooks onto id's which change when you AJAX refresh, causing the error.

You cannot refresh those otherwise you need to build yourself:

  • Input with onchange
  • List with a query as a source which is refreshed on the OnChange.

Best regards,