without changing the rule input values how to update rule input by using local variables

Question

Hi, 
 i am using multidrop down field , i want to update my new values into local variable first then i want to update into my rule input without effecting the rule input values when it is in editable condition and i have tried using the local variable but it is not getting store, can you guys guide how to solve this 
 a!multipleDropdownField(
 label:"Pets",
 placeholder:"select a value",
 choiceLabels:index(local!pets,"petsNm",null()),
 choiceValues:index(local!pets,"petsId",null()),
 value:if(
 ri!isEditable,
 ri!pets.petsIdFk,
 local!pet
 ),
 saveInto: if(
 ri!isEditable,
 {
 a!save(
 local!addition,
 a!forEach(
 items:local!pet,
 expression:'type!{urn:com:appian:types:SHA}SHA_newPets'(
 petsIdFk:fv!item,
 mappingKey: local!mappingId
 )))},
 {
 local!pet,
 a!save(
 ri!pets,
 a!forEach(
 items:local!pet,
 expression: 'type!{urn:com:appian:types:SHA}SHA_newPets'(
 petsIdFk:fv!item,
 mappingKey: local!mappingId
 )
 )
 )
 },
 
 )
 ),

gayathris0003 · Answer

a!localVariables(
local!pets: {
{ a!map(petsNm: "dog", petsId: 1) },
{ a!map(petsNm: "Cat", petsId: 2) }
},
local!mappingId: 1,


local!petsSelected_ids: index(ri!pets, "petsIdFk", null()), /* local variable which holds old pet ids and new pet ids selected*/

a!multipleDropdownField(
/*disabled: not(ri!isEditable),*/
label: "Pets",
placeholder: "select a value",
choiceLabels: index(local!pets, "petsNm", null()),
choiceValues: index(local!pets, "petsId", null()),
value: local!petsSelected_ids,
saveInto: {
local!petsSelected_ids,
a!save(ri!pets,a!forEach(
items: local!petsSelected_ids,
expression: a!map(
petsIdFk: fv!item,
mappingKey: local!mappingId
)
)
)
}
)
)