Paging in the grid creates the problem

Question

Hi Everyone , 
 
 When try to keep the batchSize in the paging info , it display that the totalnumber has been exceeded by largest column data 
 My table looks like

Type 
 Description 
 Country

Nameabc1 
 abc 
 
 Brasil , India

nameabc2 
 def 
 
 Nepal

nameabc3 
 das 
 
 Australia,USA

load(
 local!defaultPagingInfo: a!pagingInfo(
 startIndex: 1,
 batchSize: - 1,
 sort: {
 /* Default to sort in reverse chronological order */
 a!sortInfo(
 field: "Type",
 ascending: false
 )
 }
 ),
 local!pagingInfo: local!defaultPagingInfo,
 with(
 local!datasubset: todatasubset(
 a!foreach(items : rule!TAS_generateDataSubset(ID: ri!IDnum),
 expression : fv!item.data),
 local!pagingInfo),
 {
 a!gridField(
 label: "Deal Collateral",
 labelPosition: "COLLAPSED",
 totalCount: local!datasubset.totalCount,
 emptyGridMessage: resource(
 "No Collateral available"
 ),
 columns : {
 a!gridTextColumn(
 label: resource("Type"),
 field: "Type",
 data: a!forEach(
 items: local!datasubset,
 expression: a!forEach(
 items: fv!item.data,
 expression: a!forEach(
 items: fv!item,
 expression: index(
 index(
 fv!item,
 "Type",
 null
 ),
 "name",
 null
 )
 )
 )
 )
 ),
 a!gridTextColumn(
 label: resource(
 "Description"
 ),
 field: "description",
 data: a!forEach(
 items: local!datasubset,
 expression: a!forEach(
 items: fv!item.data,
 expression: a!forEach(
 items: fv!item,
 expression: index(
 fv!item,
 "description",
 null
 )
 )
 )
 )
 )
 )
 },
 value: local!pagingInfo,
 saveInto: {
 local!pagingInfo
 },
 )
 ) 
 2. a!foreach( 
 items : rule!TAS_generateDataSubset(ID: ri!IDnum), expression : fv!item.data) 
 Returns ==> [Type=[id=1, name=nameabc1], country=[id=Bra, name=Brasil]; [id=Ind, name=India], description=abc];[Type=[id=2, name=nameabc2], country=[id=Nep, name=Nepal], description=Testing def] Can anyone help me in paging the correct way .

Peter Lewis · Answer

I think the issue is with the country column, since that contains a list of lists. I'd suggest updating your expression to cast the full list of countries for the given row to a single string like this: 
 a!gridTextColumn(
 label: resource("Country"),
 field: "country",
 data: a!forEach(
 items: local!datasubset,
 expression: tostring(
 index(
 fv!item,
 "country",
 ""
 )
 )
 )
) 
 It's actually decently rare to need many nested a!forEach() functions, so usually there is a simpler solution rather than having to nest all of those together so many times!

Dave Lewis · Answer

Peter Lewis is stating basically exactly what I was about to say. 
 I'll just add that you may be able to get by with a simple joinArray() function, which you will want to do with a convenient separator to make sure your list converted to a string still looks like a list of items to your end users. You can add spaces in your separator as well, so you can make the formatting real nice. 
 Whichever method is easiest. There's no wrong answers among the things that make the pink box stop.