Can't find it it any documentation, however it should be in there somewhere... Have a microflow, creating a list of processteps, followed by a loop on these processsteps. For every processtep i need to increase the Date_Planned with 1 day. So I put the 'Change Object' action in the loop. I get a pop-up 'Edit change item', select the variable 'Date_Planned', type 'Set' is the only one selectable and I type in the white box 'AddDays($iProcessStep/Date_Planned, 1)'. Message is 'Unknown function 'AddDays''. Other things also do not work. Any idea what I should type in there? Thanx!
The things you type are case sensitive. So use addDays instead of AddDays.
Also, if you want to see a list of possible functions/objects in activity definition (or xpath constraints) use ctrl-space bar and Mendix will display a context sensitive list of functions, attributes, objects, etc. that you can choose from.