avoid the mapping gets deleted problem

app/models/events/synapse_added_to_map.rb

@@ -2,10 +2,11 @@
 class Events::SynapseAddedToMap < Event
   # after_create :notify_users!
 
-  def self.publish!(mapping, user)
+  def self.publish!(synapse, map, user, meta)
     create!(kind: 'synapse_added_to_map',
-            eventable: mapping,
+            eventable: synapse,
-            map: mapping.map,
+            map: map,
-            user: user)
+            user: user,
+            meta: meta)
   end
 end

app/models/events/synapse_removed_from_map.rb

@@ -2,10 +2,11 @@
 class Events::SynapseRemovedFromMap < Event
   # after_create :notify_users!
 
-  def self.publish!(synapse, map, user)
+  def self.publish!(synapse, map, user, meta)
     create!(kind: 'synapse_removed_from_map',
             eventable: synapse,
             map: map,
-            user: user)
+            user: user,
+            meta: meta)
   end
 end

app/models/events/topic_added_to_map.rb

@@ -2,10 +2,10 @@
 class Events::TopicAddedToMap < Event
   # after_create :notify_users!
 
-  def self.publish!(mapping, user, meta)
+  def self.publish!(topic, map, user, meta)
     create!(kind: 'topic_added_to_map',
-            eventable: mapping,
+            eventable: topic,
-            map: mapping.map,
+            map: map,
             user: user,
             meta: meta)
   end

app/models/events/topic_moved_on_map.rb

@@ -2,10 +2,10 @@
 class Events::TopicMovedOnMap < Event
   # after_create :notify_users!
 
-  def self.publish!(mapping, user, meta)
+  def self.publish!(topic, map, user, meta)
     create!(kind: 'topic_moved_on_map',
-            eventable: mapping,
+            eventable: topic,
-            map: mapping.map,
+            map: map,
             user: user,
             meta: meta)
   end

app/models/events/topic_removed_from_map.rb

@@ -2,10 +2,11 @@
 class Events::TopicRemovedFromMap < Event
   # after_create :notify_users!
 
-  def self.publish!(topic, map, user)
+  def self.publish!(topic, map, user, meta)
     create!(kind: 'topic_removed_from_map',
             eventable: topic,
             map: map,
-            user: user)
+            user: user,
+            meta: meta)
   end
 end

app/models/mapping.rb

@@ -30,17 +30,17 @@ class Mapping < ApplicationRecord
 
   def after_created
     if mappable_type == 'Topic'
-      meta = {'x': xloc, 'y': yloc}
+      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
-      Events::TopicAddedToMap.publish!(self, user, meta)
+      Events::TopicAddedToMap.publish!(mappable, map, user, meta)
     elsif mappable_type == 'Synapse'
-      Events::SynapseAddedToMap.publish!(self, user)
+      Events::SynapseAddedToMap.publish!(mappable, map, user, meta)
     end
   end
 
   def after_updated
     if mappable_type == 'Topic' and (xloc_changed? or yloc_changed?)
-      meta = {'x': xloc, 'y': yloc}
+      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
-      Events::TopicMovedOnMap.publish!(self, user, meta)
+      Events::TopicMovedOnMap.publish!(mappable, map, user, meta)
     end
   end
 
@@ -51,10 +51,11 @@ class Mapping < ApplicationRecord
       mappable.save
     end
 
+    meta = {'mapping_id': id}
     if mappable_type == 'Topic'
-      Events::TopicRemovedFromMap.publish!(mappable, map, user)
+      Events::TopicRemovedFromMap.publish!(mappable, map, user, meta)
     elsif mappable_type == 'Synapse'
-      Events::SynapseRemovedFromMap.publish!(mappable, map, user)
+      Events::SynapseRemovedFromMap.publish!(mappable, map, user, meta)
     end
   end
 end

app/models/webhooks/slack/synapse_added_to_map.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 class Webhooks::Slack::SynapseAddedToMap < Webhooks::Slack::Base
   def text
-    connector = eventable.mappable.desc.empty? ? '->' : eventable.mappable.desc
+    connector = eventable.desc.empty? ? '->' : eventable.desc
-    "\"*#{eventable.mappable.topic1.name}* #{connector} *#{eventable.mappable.topic2.name}*\" was added as a connection by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
+    "\"*#{eventable.topic1.name}* #{connector} *#{eventable.topic2.name}*\" was added as a connection by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
   end
 end

app/models/webhooks/slack/topic_added_to_map.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 class Webhooks::Slack::TopicAddedToMap < Webhooks::Slack::Base
   def text
-    "*#{eventable.mappable.name}* was added by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
+    "*#{eventable.name}* was added by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
   end
   # TODO: it would be sweet if it sends it with the metacode as the icon_url
 end

app/models/webhooks/slack/topic_moved_on_map.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 class Webhooks::Slack::TopicMovedOnMap < Webhooks::Slack::Base
   def text
-    "*#{eventable.mappable.name}* was moved by *#{event.user.name}* on the map *#{view_map_on_metamaps}*"
+    "*#{eventable.name}* was moved by *#{event.user.name}* on the map *#{view_map_on_metamaps}*"
   end
 end