Attribute Storing Another Attribute Conditionally

Hi – I’m trying to add an attribute (say Attribute3)  that stores the value of another attribute (say Attribute1 or Attribute2) conditionally. The logic would be: if Attribute1 is blank then save the value of Attribute2 into Attribute3 else save the value of Attribute1 into Attribute3 How can I best accomplish this? I’ve searched the forums and have seen microflow and enumeration. Not sure how best to put this into practice.  
2 answers

Do action “Change Object” for your object, select Attribute3, give it this value:

if ($Object/Attribute1 = empty or $Object/Attribute1 = '')
then $Object/Attribute2
else $Object/Attribute1

Or the more elaborate Mendix way:


Thanks!  I had started something like the first option, so glad I was on the right track … Do I need to trigger this microflow somewhere?