Trigger to default Select to default value or previous selection

[nickedw0]

I use the following trigger to set a Year field selection to Variable1 if Year has no prior selection, or to its previous value. This works if only a single year is preselected. But if multiple years are selected, it fails. Any help would be appreciated.

=if(len(getFieldSelections(Year))=0,Year(Variable1),getFieldSelections(Year))

Thanks

[sunny_talwar]

What is Variable1 here?

[nickedw0]

Variable1 has the current date

[sunny_talwar]

So when multiple years are selected, then which would be the previous year? Lets say you selected 2017 and 2016, previous year will be 2015?

[woshua5550]

Try this 

=if(getselectioncount(Year)=0,Year(Variable1),'|'&concat(Year,',')&'|')

[woshua5550]

Sorry, ignore above

It would be

=if(getselectedcount(Year)=0,Year(Variable1),'('&concat(Year,'|')&')')

[nickedw0 · Accepted solution]

This is close to perfect. I changed to:

=if(getselectedcount(Year)=0,Year(Variable1),'('&concat(Year,'|')&')')

Problem is each iteration adds a set of brackets, like (((2015|2016))) after 3rd time sheet is selected. or ((((((2015|2016)))))) after 6th.

[nickedw0]

Ok, That was the correct answer. The extra brackets were comming from an exit trigger I forgot to remove.

[woshua5550]

Ok,you can mark my answer as correct answer if it was helpful, have a good day:)