Issues with a!multipleDropdownField_20r2() in an Editable grid

Question

a!gridLayout(
 emptyGridMessage: "No Claims assigned", 
 headerCells: {
 a!gridLayoutHeaderCell(label: "Dietary Ingredient"),
 a!gridLayoutHeaderCell(label: "Claim"),
 a!gridLayoutHeaderCell(label: "Decision"),
 a!gridLayoutHeaderCell(label: "Category"),
 /*a!gridLayoutHeaderCell(label: "Updated Cat"),*/
 a!gridLayoutHeaderCell(label: "Keywords"),
 a!gridLayoutHeaderCell(label: "Comments"),
 a!gridLayoutHeaderCell(label: "RFI")
 },
 columnConfigs: {
 a!gridLayoutColumnConfig(width: "DISTRIBUTE"),
 a!gridLayoutColumnConfig(width: "DISTRIBUTE"),
 a!gridLayoutColumnConfig(width: "NARROW_PLUS"),
 a!gridLayoutColumnConfig(width: "DISTRIBUTE"),
 /*a!gridLayoutColumnConfig(width: "WIDE"),*/
 a!gridLayoutColumnConfig(width: "DISTRIBUTE"),
 a!gridLayoutColumnConfig(width: "DISTRIBUTE"),
 a!gridLayoutColumnConfig(width: "NARROW")
 },
 rows: {
 a!forEach(
 items: ri!claims_cdt,
 expression: {
 a!localVariables(
 local!category: a!refreshVariable(
 value: index(rule!SFC_getCategoriesByClaimsId( claimId_int: index(fv!item, "claimId_int", "")), "categoryDesc_text", null), 
 refreshOnReferencedVarChange: true
 ),
 local!newCategory_cdt:'type!{urn:com:appian:types:farm}SFC_category'(claimId_int: index(fv!item, "claimId_int", "") ),
 local!totalNewCategory_cdt:'type!{urn:com:appian:types:farm}SFC_category'(claimId_int: index(fv!item, "claimId_int", "") ),

 a!gridRowLayout(
 id: fv!index,
 contents: {
 a!textField(
 label: "Dietary Ingredient",
 value: fv!item.dietaryIngredient_text,
 readOnly: true
 ),
 a!textField(
 label: "Claim",
 value: fv!item.claim_text,
 readOnly: true
 ),
 if(
 ri!readOnly_bool,
 a!textField(
 label: "Decision",
 value: fv!item.reviewDecisionId_int, 
 readOnly: true
 ),

 

 a!dropdownField_20r2(
 label: "Decision",
 placeHolderlabel: "-- Review Decision --",
 choiceLabels:local!reviewDecisions_cdts.value_text,
 choiceValues:tointeger(local!reviewDecisions_cdts.lookupId_int),
 value: if(
 rule!FARM_isNullOrEmpty(fv!item.reviewDecisionId_int),
 null, 
 fv!item.reviewDecisionId_int
 ),
 saveInto: fv!item.reviewDecisionId_int,
 required: not(
 rule!FARM_isNullOrEmpty(local!categoriesSelected_texts)
 ),
 disabled: false
 ) 
 ),
 if(
 ri!readOnly_bool,
 a!richTextDisplayField(
 label: "Category",
 value: a!richTextBulletedList(
 items: union(
 local!categoriesSelected_texts,
 local!categoriesSelected_texts
 )
 )
 ),
 a!multipleDropdownField_20r2(
 label: "Category",
 labelPosition: "ADJACENT",
 placeHolder: "-- Select Categories -- ",
 choiceLabels: local!categoryTypes_cdts.value_text,
 choiceValues: local!categoryTypes_cdts.value_text,
 value: local!category,
 saveInto: {
 local!category,
 a!forEach(
 items: local!category,
 expression: 
 {
 a!save(local!newCategory_cdt.categoryDesc_text,fv!item),
 a!save(local!newCategory_cdt.isActive_bool, 1),
 /*a!save(local!totalNewCategory_cdt,union(wherecontains(local!category,local!totalNewCategory_cdt.categoryDesc_text),local!newCategory_cdt)),*/
 /*a!save(ri!newCategory_cdt,reject(fn!isnull, union(ri!newCategory_cdt,local!totalNewCategory_cdt))),*/

 }
 )

 }, 
 required: not(
 rule!FARM_isNullOrEmpty(
 fv!item.reviewDecisionId_int
 )
 ) 
 )
 ), Hello, 
 I have an editable grid with a multiselect dropdown (Ex: Claims and each row is a separate claim Id). Values in multiselect dropdown are pulled from a separate table (Ex: Category pulled based on Claim ID for each row) 
 I'm facing difficulties saving categories to ri! value. When a value is unselected, it isn't getting removed from ri! 
 Appreciate any help in resolving this issue, TIA.

Mike Schmitt · Answer

I can't imagine this is what you actually want the behavior to be, but just to clarify, the code seen here:

means that if you select multiple items from the list, then each iteration of the forEach() loop iterating over the "local!category" items, the a!save() highlighted will overwrite the "categoryDesc_text" property of the [single] local!newCategory_cdt variable - ultimately just landing on whatever's latest in the local!category list.

Mike Schmitt · Answer

But what I'm asking is, what are you doing with "local!totalNewCategory_cdt"? To clarify what I mean: 
 
 what are you hoping the local variable will look like / contain when, for example, 2 or 3 items are selected from the dropdown list? 
 what happens to this local variable after that? in your code snippet it's not ever being used for anything 
 considering that you'll have a list of these local variables for each row in the grid, how exactly will each row's individual list of items be associated with that grid row?