Nested a!foreach data not displaying

Question

I am working on an interface that has 3 nested a!foreach functions. The third level down does not always see the correct information in a cdt, often times it see information as null when there is data in the table. For example, fv!item.ItemSchedule will yield results, but fv!item.ItemSchedule.ItemDeliverySchedule will not, even though according to the table, there is information in fv!item.ItemSchedule.ItemDeliverySchedule. Any thoughts?

vijayd · Answer

Defining fv!item in a local variable and referencing it will solve this problem.

aloks0189 · Answer

Hi idar As per my understanding, you are facing this issue due to ambiguous situation, because you have nested looping where each forEach() contains their fv!item, hence this issue is getting arise. 
 
So i suggest try to split the last 2 looping into 2 additional expression rules and call them the first expression rule into the main rule first looping and the 2nd expression rule into the 1st expression rule looping, this will do you job. 
 
Also, you need to consider, such type of looping (3 nested) may cause performance issue, in case if large amount of data need to be process. 
 
Hope this will help you.

Carlos Santander · Answer

If you have nested a!foreach, you also have nested fv!item, which might be getting Appian confused. Have you tried breaking the expression into multiple rules, passing fv!item explicitly as a rule input? 
 
a!foreach( <your list>, rule!level1( level1Item: fv!item) ) 
 
You would then reference ri!level1Item instead of fv!item, and repeat the same pattern for the next nesting levels.

gianninol · Answer

Another option for nesting forEaches is to use a with to capture fv!item in a local variable so that it can be referenced unambiguously within the nested loops. 
 
For example, a!forEach(items: ri!list1, expression: with( local!parentItem: fv!item, a!forEach(items: local!parentItem, expression: <some expression>))).

Nested a!foreach data not displaying

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