<div class="slds-grid slds-gutters, slds-is-edited" style="margin-left:2px;">
                <lightning:datatable aura:id="conlistId"
                                     data="{!v.wrapperDataRec.contactData}"
                                     columns="{!v.oppCols}"
                                     keyField="Id"
                                     hideCheckboxColumn="false"
                                     showRowNumberColumn="true"
                                     onsave="{!c.handleSaveTable}"/>
            </div> <br/>

handleSaveTable : function(component, event, helper) {
        var action = component.get("c.saveContact");
        var drafts = event.getParam('draftValues');
        action.setParams({"conList" : drafts});
        action.setCallback(this, function(response){
            if(response.getState() === "SUCCESS"){
                $A.get('e.force:refreshView').fire();
            }
        });
        $A.enqueueAction(action);
        component.find("conlistId").set("v.draftValues", null);
        //alert('Save working fine');
    }