How can we save calculated value in rule input

Question

How can we save calculated value in rule input without user interaction in field ??

Mike Schmitt · Answer

Generally speaking, saving a value back into a rule input *always* requires user interaction. Can you give some additional detail into your use case?

Mike Schmitt · Answer

Unknown said: is it any way to store that value into rule input without user interaction? 
 As i said before, the answer here is pretty much "no" - which is why I asked some more details of your use case. By use case, I really mean the steps a user is going to take and your desired result, not just a re-phrasing of your original question. Such as - if the user will be clicking any buttons or anything else in the interface (such as a submit button), then you can potentially perform the back-save in other locations; but I don't know what to recommend without further details.