Invalid index (5) for list: valid range is 1..4

Question

Hi team, 
 When I am choosing multiple options at one particular time I am getting this error. Please help me to solve this error. 
 Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function a!forEach [line 42]: Error in a!forEach() expression during iteration 1: Expression evaluation error at function a!multipleDropdownField [line 199]: Invalid index (5) for list: valid range is 1..4 
 
 a!localVariables(
 local!pets:rule!SHA_refPets(),
 local!selectedValue:index(ri!pets, "petsIdFk", null()),
 local!originalArray: a!refreshVariable(
 value: local!selectedValue,
 refreshOnReferencedVarChange: false
 ),
 local!delete,
 local!insert,
 local!update,
 local!deleteCDT,
 local!insertCDT,
 local!updateCDT,
 local!mappingId:index(local!mappingKey,fv!index,null),
 {
 a!multipleDropdownField(
 label: "Pets" ,
 placeholder: "select a value",
 choiceLabels: index(local!pets, "petsNm", null()),
 choiceValues: index(local!pets, "petsId", null()),
 value: local!selectedValue[wherecontains(true(),ri!pets.isActive)],
 saveInto: {
 local!selectedValue,
 a!save(
 local!update,
 intersection(
 tointeger(local!selectedValue),
 tointeger(local!originalArray)
 )
 ),/*getting updated item*/
 a!save(
 local!delete,
 difference(

 tointeger(local!originalArray),
 tointeger(local!selectedValue),
 )
 ),/*getting deleted item*/
 a!save(
 local!insert,
 difference(
 tointeger(local!selectedValue),
 tointeger(local!originalArray),

 )
 ),/*getting new item*/
 a!save(
 local!insertCDT,
 a!forEach(
 items: local!insert,
 expression: 'type!{urn:com:appian:types:SHA}SHA_newPets'(
 petsId: null,
 listingIdFk: index(ri!pets.listingIdFk, 1, null),
 petsIdFk: fv!item,
 mappingKey: null,
 isActive: true
 )
 )
 ),/*Creating CDT for new item*/
 a!save(
 local!deleteCDT,
 index(
 ri!pets,
 wherecontains(
 tointeger(local!delete),
 tointeger(ri!pets.petsIdFk)
 )
 )
 ),/*getting deleted index item*/
 a!save(
 local!deleteCDT,
 a!forEach(
 items: local!deleteCDT,
 expression: 'type!{urn:com:appian:types:SHA}SHA_newPets'(
 petsId: fv!item.petsId,
 listingIdFk: fv!item.listingIdFk,
 petsIdFk: fv!item.petsIdFk,
 mappingKey: fv!item.mappingKey,
 isActive: false,
 createdBy: fv!item.createdBy
 )
 )
 ),/*CDT Creation for Deleted item*/
 a!save(
 local!updateCDT,
 index(
 ri!pets,
 wherecontains(
 tointeger(local!update),
 tointeger(ri!pets.petsIdFk)
 )
 )
 ),/*getting updated item index*/
 a!save(
 ri!pets,
 reject(
 fn!isnull,
 append(
 local!updateCDT,
 local!deleteCDT,
 local!insertCDT
 )
 )
 )/*Final*/
 }
 )
 }

Mike Schmitt · Answer

Why are you doing this? 
 value: local!selectedValue[wherecontains(true(),ri!pets.isActive)], 
 I would actually expect this to not work - the whereContains() statement wil return all indices of ri!pets where isActive is true, which is *not* relevant to the length of or current selections in local!selectedValue . 
 Instead, you should probably start out with the standard simple version, 
 value: local!selectedValue

Mike Schmitt · Answer

That isn't how the value parameter is intended to work, though. What you've written will break, for the specific reason I noted. If you want users to be unable to select certain values depending on background conditions, I suggest you handle that within a Validation, instead of messing with the choices or the current value. 
 Also, you're executing a whole lot of logic in the saveInto of your multiple dropdown - these will all run every single time the selected value is changed. I would strongly suggest that you move this logic into a button click or link, to be run only after the user's selections might be finalized.

Mike Schmitt · Answer

There's a fundamental issue here with the notion that deselecting items on your list instantly makes them "deleted", i think. This level of complexity is essentially setting yourself up for failure. 
 I'm not really even clear what your use case is, but as always my underlying suggestion is to simplify to something that works, and then gradually add back some complexity if and only if needed.

Mike Schmitt · Answer

This appears to be a picture of the (collapsed) multiple dropdown field - what I said above still applies. The only thing needed to "remove" values from this is to deselect them as normal.

Mike Schmitt · Answer

that's fine - the logic you're doing in the saveInto field appears to be handling this (assuming it works), but my point is that you do *not* need to do manipulation on the "value" parameter like you're currently doing. The "value" parameter should simply point at the "selected values" array.

Mike Schmitt · Answer

when you say "displaying the items", do you mean as choices or as selected values? If de-selecting them causes them to get an active status of "false", i'm not sure what's happening. Again I must point to my points of advice above and strongly recommend you simplify down to something you understand (and that works), and build up from there.