create options in a dropdown based on another dropdown

I am trying to have a pop-up page with 2 dropboxes. The first one should show a list of objects and the second dropbox should show projects. projects are assigned to an object. the way I want to make it is that you have to select an object and this filters the second dropbox to only show projects assigned to the selected object. I've tried to do it another way by creating a page where I select an object, which opens a pop-up where you have to select the project. I tried to put a miecroflow on click action. Where I input the object, create a variable that takes the object number as value. Open the project selection pop-up page. The I use a Retrieve from database to retrieve a list of projects where the object_number is equal to the variable I've created. The data list gets the info from the microflow. When I do this there is no error given, but when I try to run it, I get an infinite loading bar when I click an object.
3 answers

I think the way I got it right now should work, but found another issue.

In my project creation page, I use a dropdown to select the object the project is being done for. I want to save these selected values to the correct attribute in the project entity.

For some reason the project attributes object_name and object_number stay empty.


Some more screenshots of my problem.

the change object inside the microflow


the new project creation page.



You might want to look at the contrained by function. See documentation here:

For some strange reason this is only explained in the Mx7 documentation but can also be applied to the current versions of Mendix.