Setting Dependent Custom Lightning Picklist Level2 and Level3 then resetting the Level2 at Lightning component but Level2 Cached Data is Getting Saved

Question

Step 1

In a Salesforce Lightning component I have a scenario with three levels of dependent picklists, first I am setting values for picklist Level1, and

Answer 1

This got fixed because I not refreshing the Level 3 picklist when the Level 1 picklist was getting changed,so added an onchange at Level3

Also copied getSelectedValue to Helper at getLvl1 function using helper.getSelectedValue(component,event,helper); (It is to be remembered one good use of helper class is this when we need some code or method to be repeatedly called,so its better to put that function in helper ) and called again at component also changed the with new aura components like

Here is component

                
                    
                    
                  
                    
                    
                     
                      
                        
                     
                      
                    
                       

                        

                             
                            
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                                    {!value}
                                
                            
                             
                            
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                                    {!value}
                                
                            
                            
                             
                                --- None ---
                                
                                    {!value}
                                
                            
                             
                        
        
                    
                   
                

Here is controller js

                doInit : function(component, event, helper) {
                    var action = component.get("c.getLevel1");
                    action.setCallback(this, function(e) {
                        if(e.getState()=='SUCCESS'){
                            var result=e.getReturnValue();
                            component.set("v.lstLevel1",result);
                        }
                    });
                    $A.enqueueAction(action);
                },    
                getLvl1:function(component, event, helper){
                   
                    var picklist=component.find('ddLevel1');
                    var picklistvalue=picklist.get('v.value');
                    component.set("v.firstlevel1selected",picklistvalue);
                    var action = component.get("c.getLevel2");
                    action.setParams({  'strName' : picklistvalue  });
                    action.setCallback(this, function(e) {
                        if(e.getState()=='SUCCESS'){
                            var result=e.getReturnValue();
                            component.set("v.lstLevel2",result);
                            helper.getSelectedValue(component,event,helper);
                        }
                    });
                    $A.enqueueAction(action);
                        },
                getSelectedValue:function(component, event, helper){
                    var picklist=component.find('ddLevel1');
                   
                    var picklistvalue=picklist.get('v.value');
                     
                    var picklistdep=component.find('ddLevel2');
                    
                    var picklistvaluedep2=picklistdep.get('v.value');
                    component.set("v.secondlevelselected",picklistvaluedep2);
                    var action = component.get("c.getLevel3");
                    
                    action.setParams({  'strName1' : picklistvalue,
                                     'strName2' : picklistvaluedep2});//
                    action.setCallback(this, function(e) {
                        if(e.getState()=='SUCCESS'){
                            var result=e.getReturnValue();
                            component.set("v.lstL3",result);
                        }
                    });
                    $A.enqueueAction(action);
                },
                getlevel3:function(component, event, helper){
                    var picklist=component.find('ddLevel3');
                   
                    var picklistvalue=picklist.get('v.value');
                     component.set("v.thirdlevelselected",picklistvalue);
                    
                },
                onConfirm:function(component, event, helper){
                    var picklist=component.find('ddLevel1');
                    var picklistvalue=picklist.get('v.value');
                    var picklistdep=component.find('ddLevel2');
                    var picklistvaluedep2=picklistdep.get('v.value');
                   
                    var picklistdep3=component.find('ddLevel3');
                    var picklistvaluedep3=picklistdep3.get('v.value');
                    console.log(component.get('v.firstlevel1selected'));
                     console.log(component.get('v.secondlevelselected'));
                     console.log(component.get('v.thirdlevelselected'));
                    
                    var action = component.get("c.savecasetype");
                    
                    action.setParams({  'level1' : picklistvalue,
                                      'level2' : picklistvaluedep2,
                                      'level3' : picklistvaluedep3,
                                      'id' : component.get("v.recordId")});
                                      
                    
                    var toastEvent = $A.get("e.force:showToast");
                    action.setCallback(this, function(e) {
                        if(e.getState()=='SUCCESS'){
                            var result=e.getReturnValue();
                            if(result==='successfull'){
                                toastEvent.setParams({
                                    "title": "Success!",
                                    "message": "The record has been inserted  successfully."
                                });
                                toastEvent.fire();
                            }else{
                                toastEvent.setParams({
                                    "title": "Error",
                                    "message": "The record has not been inserted  successfully."
                                });
                                toastEvent.fire();
                            }
                        }
                    });
                    $A.enqueueAction(action);
                   
                },
                   
                   
            })              

Here is helper class

            ({
                 getSelectedValue:function(component, event, helper){
                    var picklist=component.find('ddLevel1');
                   
                    var picklistvalue=picklist.get('v.value');
                     
                    var picklistdep=component.find('ddLevel2');
                    
                    var picklistvaluedep2=picklistdep.get('v.value');
                    component.set("v.secondlevelselected",picklistvaluedep2);
                    var action = component.get("c.getLevel3");
                    
                    action.setParams({  'strName1' : picklistvalue,
                                     'strName2' : picklistvaluedep2});//
                    action.setCallback(this, function(e) {
                        if(e.getState()=='SUCCESS'){
                            var result=e.getReturnValue();
                            component.set("v.lstL3",result);
                        }
                    });
                    $A.enqueueAction(action);
                },
                getlevel3:function(component, event, helper){
                    var picklist=component.find('ddLevel3');
                   
                    var picklistvalue=picklist.get('v.value');
                     component.set("v.thirdlevelselected",picklistvalue);
                    
                }
            })