fix for remove event

src/main/java/ru/ulstu/timeline/model/Event.java

@@ -4,6 +4,7 @@ import org.hibernate.validator.constraints.NotBlank;
 import ru.ulstu.core.model.BaseEntity;
 import ru.ulstu.user.model.User;
 
+import javax.persistence.CascadeType;
 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.EnumType;
@@ -66,6 +67,10 @@ public class Event extends BaseEntity {
     @JoinColumn(name = "child_id")
     private Event child;
 
+    @OneToMany(cascade = CascadeType.ALL)
+    @JoinColumn(name = "child_id")
+    private List<Event> parents;
+
     public String getTitle() {
         return title;
     }
@@ -137,4 +142,12 @@ public class Event extends BaseEntity {
     public void setChild(Event child) {
         this.child = child;
     }
+
+    public List<Event> getParents() {
+        return parents;
+    }
+
+    public void setParents(List<Event> parents) {
+        this.parents = parents;
+    }
 }

src/main/java/ru/ulstu/timeline/service/EventService.java

@@ -57,8 +57,9 @@ public class EventService {
     }
 
     @Transactional
-    public void delete(Integer timelineId) {
-        Event event = eventRepository.findOne(timelineId);
+    public void delete(Integer eventId) {
+        Event event = eventRepository.findOne(eventId);
+        event.setParents(null);
         eventRepository.delete(event);
     }