doInit: function(component, event, helper){

    helper.fetchTOPicklistValues(component, 'Offer_Status__c', 'Offer_Outcome__c');

},  

// function call onchange controller field  
onControllerTOFieldChange: function(component, event, helper) {

    // get the selected value
    var controllerValueKey = event.getSource().get("v.value");

    // get the map values   
    var Map = component.get("v.dependentFieldMap");

    // check if selected value is not equal to None then call the helper function.
    // if controller field value is none then make dependent field value is none and disable field
    if (controllerValueKey != '-- None --') {

        // get dependent values for controller field by using map[key].  
        var ListOfDependentFields = Map[controllerValueKey];
        helper.fetchDepValuesType(component, ListOfDependentFields);

    } else {
        var defaultVal = [{
        class: "optionClass",
        label: '-- None --',
        value: '-- None --'
        }];
        component.find('Offer_Outcome__c').set("v.options", defaultVal);
        component.set("v.isDependentDisableTO", false);

    }
},

onDependentTOFieldChange: function(component, event, helper) {

    var onDep = event.getSource().get("v.value");

},

fetchTOPicklistValues: function(component, controllerField, dependentField) {

      // call the server side function  
      var action = component.get("c.getFieldDependencies");
      // pass parameters [object name, controller field name, dependent field name]
      // to server side function 

      action.setParams({
         'objApiName': component.get("v.objTOInfo"),
         'contrfieldApiName': controllerField,
         'depfieldApiName': dependentField
      });

      //set callback   
      action.setCallback(this, function(response) {

         if (response.getState() == "SUCCESS") {

            //store the return response from server (map<string,List<string>>)  
            var StoreResponse = response.getReturnValue();

            // once set #StoreResponse to dependentFieldMap attribute 
            component.set("v.dependentFieldMap", StoreResponse);

            // create a empty array for store map keys(@@--->which is controller picklist values) 
            var listOfkeys = []; // for store all map keys (controller picklist values)
            var ControllerField = []; // for store controller picklist value to set on ui field. 

            // play a for loop on Return map 
            // and fill the all map key on listOfkeys variable.
            for (var singlekey in StoreResponse) {

               listOfkeys.push(singlekey);

            }

            //set the controller field value for ui:inputSelect  
            if (listOfkeys != undefined && listOfkeys.length > 0) {

               ControllerField.push({
                  class: "optionClass",
                  label: "-- None --",
                  value: "-- None --"
               });

            }

            for (var i = 0; i < listOfkeys.length; i++) {

               ControllerField.push({
                  class: "optionClass",
                  label: listOfkeys[i],
                  value: listOfkeys[i]
               });

            }

            // set the ControllerField variable values to controller picklist field
            component.find("Offer_Status__c0").set("v.options", ControllerField);
         } else {

            console.log("ERROR : ", response);
            var errors = action.getError();
            console.log('ERROR Val : ', response.getError());

         }
      });
      $A.enqueueAction(action);
   },