lookup filter using multiselect picklist

Question

I have a lookup field on an object and when a user selects a value in that field and i have throw an error if it does not fulfill certain filter criteria. Since filter criteria does not work on multi select picklist how i can do this?

On the object a i have a field - version which is a picklist.

on object b i have a field version which is a multiselect

Object a has a field which is a lookup to object b and only a record of object b which contains the version on object a as one of the options in the multiselect can be accepted. If it does not fulfill the criteria it should throw an exception. Any help will be much appreciated

Answer 1

Hi you can have trigger on Child object to check if value selected in Child picklist is present in parent object's MultiSelect Picklist or not.

Giving you example using Account as Parent and contact as child

Account has Multi_version__c field as multi Select, While Contact has Version__C as picklist

trigger TgrPreventVersionSelection on Contact (after Insert, before update) {

   // first find Accounts to get multi Select pickList values 
   Set<Id> AccIds = new set<Id>();
   For(Contact c : Trigger.new) 
      {
        if(c.AccountId != null)
        AccIds.add(c.AccountID);
      }

   // Thsis map will  have parent object Id( Account here) and values of multiSelectPicKlist in Set. 
   Map<Id, set<string>> mpAcWithMultiPickList = new map<Id, set<string>>();
   List<Account> AccList = new list<Account>(); 



   AccList =  [select id, name, Multi_version__c from Account where Id = :AccIds];

  // once We have Accounts, we'll populate a map having Account ID and set of string present in multi Select piclist

   For(Account acc : Acclist)
    {
     if(acc.Multi_version__c != null)
       { 
          list<String> slist = acc.Multi_version__c.split(';');
          set<String> versionStringSet = new set<string>(slist);
           mpAcWithMultiPickList.put(acc.id, versionStringSet); //converting list to set
        }// end of If condition
    }// for loop

   // Once we've map of Account and Set, we can ran check to see value selected in child is present in parent's multiselect(set of string) or not
    For(contact c : trigger.new) 
      {
        if(c.AccountId != null)
          { 
            Set<string> SettoCompare =mpAcWithMultiPickList.get(c.AccountId);

              If(!SettoCompare.contains(c.version__c))
                c.addError('Version doesn\'t Exist in Parent');
          }

      }   
}