Running validation before the record save

Question

I'm running some validations and the validations are that: Every Employee should have two languages (English & Spanish) associated with it language type. (Lang_Type__c)

Otherwise user should not able to save the record and throw the validation errors, the below code works but not all the time, sometimes the validations pass even though the validation should failed. To give you an example, the user able to Save the record just by adding the English (should add both English/Spanish for that specific lang_type__c)

Lang_type__c = picklist (first language, home language)

So if I select lang_type__c = 'first language' or 'home language' then I should have both Language__c = English and Spanish

Here is my code:

public static boolean ValidateLanguage(Id empId)  
{
    List<Emp_Languages__c> langList =  [SELECT Id, Name, Language__c, Lang_Type__c FROM Emp_Languages__c WHERE Id =: empId];

    map<string, boolean> mapLang = new map<string, boolean>();

    for(Emp_Languages__c l : langList) 
    {
       if(String.isNotEmpty(l.Lang_Type__c)) {
          mapLang.put(l.Lang_Type__c, true);  
       }
       else {
          mapLang.put(l.Lang_Type__c, false);  
       } 
    }

    boolean validationPass = true;
    boolean hasEnSp = false;
    String employeeLang = ''; 
    boolean langEnglish = false;
    boolean langSpanish = false;

    for(Emp_Languages__c lang : langList) 
    {
       hasEnSp = mapLang.get(lang.Lang_Type__c);  
       if(!hasEnSp ) 
       {
         employeeLang = '';              
         if(lang.Language__c == 'English') 
         { 
           employeeLang = 'English';
           langEnglish = true;
         }
         if (lang.Language__c == 'Spanish') 
         { 
            employeeLang = 'Spanish';
            langSpanish = true;
         }
         ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.ERROR,'There should be two language English/Spanish');
         ApexPages.addMessage(myMsg); 

         validationPass = false;

   }
     return validationPass && langEnglish && langSpanish ;      
    }

just to give you an sample data:

should validation fail: 

Id     Name         Language__c       Lang_Type__c
1      test         English           first language
2      abc          Spanish           home language 

should validation pass:

Id     Name         Language__c       Lang_Type__c
1      test         English           first language
2      abc          Spanish           first language 

Answer 1

From the langList which is returned from your SOQL, prepare a Set<String> which will contain only Language__c. Set will not contain duplicate.

Verify the Size of Set <2, it will throw the error message.

Sample code will look like this:

List<Emp_Languages__c> langList =  [SELECT Id, Name, Language__c, Lang_Type__c FROM Emp_Languages__c WHERE Id =: empId];

Set<String> LangSet = new Set<String>();
String prevLangType=''; 
for(Emp_Languages__c l : langList) 
{   
   if(String.isNotEmpty(l.Lang_Type__c) && (prevLangType=='' || l.Lang_Type__c == prevLangType)) {
        LangSet.add(l.Language__c);
        prevLangType = l.Lang_Type__c;
   }       
}

if(LangSet.size()<2)
{
    ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.ERROR,'There should be two language English/Spanish');
    ApexPages.addMessage(myMsg);
}