Revert "Migrates alerts to an object-oriented implementation"

This reverts commit fbc283f12f.

scripts/lua/modules/alert_definitions/alert_device_connection.lua

@@ -2,49 +2,29 @@
 -- (C) 2019-20 - ntop.org
 --
 
--- ##############################################
-
 local alert_keys = require "alert_keys"
 local alert_creators = require "alert_creators"
--- Import the classes library.
-local classes = require "classes"
--- Make sure to import the Superclass!
-local alert = require "alert"
 
--- ##############################################
-
-local alert_device_connection = classes.class(alert)
-
--- ##############################################
-
-alert_device_connection.meta = {
-  alert_key = alert_keys.ntopng.alert_device_connection,
-  i18n_title = "alerts_dashboard.device_connection",
-  icon = "fas fa-sign-in",
-}
-
--- ##############################################
+-- #######################################################
 
 -- @brief Prepare an alert table used to generate the alert
+-- @param alert_severity A severity as defined in `alert_severities`
 -- @param device The a string with the name or ip address of the device that connected the network
 -- @return A table with the alert built
-function alert_device_connection:init(device)
-   -- Call the paren constructor
-   self.super:init()
+local function createDeviceConnection(alert_severity, device)
+  local built = {
+    alert_severity = alert_severity,
+    alert_type_params = {
+       device = device,
+    },
+  }
 
-   self.alert_type_params = {
-    device = device,
-   }
+  return built
 end
 
 -- #######################################################
 
--- @brief Format an alert into a human-readable string
--- @param ifid The integer interface id of the generated alert
--- @param alert The alert description table, including alert data such as the generating entity, timestamp, granularity, type
--- @param alert_type_params Table `alert_type_params` as built in the `:init` method
--- @return A human-readable string
-function alert_device_connection.format(ifid, alert, alert_type_params)
+local function formatDeviceConnectionAlert(ifid, alert, info)
   return(i18n("alert_messages.device_has_connected", {
     device = info.device,
     url = getMacUrl(alert.alert_entity_val),
@@ -53,4 +33,10 @@ end
 
 -- #######################################################
 
-return alert_device_connection
+return {
+  alert_key = alert_keys.ntopng.alert_device_connection,
+  i18n_title = "alerts_dashboard.device_connection",
+  i18n_description = formatDeviceConnectionAlert,
+  icon = "fas fa-sign-in",
+  creator = alert_creators.createDeviceConnectionDisconnection,
+}