Initial/stub implementation of a factory for generating alerting objects.

1 files changed, 70 insertions, 0 deletions

diff --git a/lib/custodian/alertfactory.rb b/lib/custodian/alertfactory.rb
new file mode 100644
index 0000000..f82706f
--- /dev/null
+++ b/lib/custodian/alertfactory.rb
@@ -0,0 +1,70 @@
+
+
+#
+#
+# Base class for custodian alerters.
+#
+# Each subclass will register themselves, via the call
+# to 'register_alert_type'.
+#
+# This class is a factory that will return the correct
+# derived class.
+#
+#
+module Custodian
+
+  class AlertFactory
+
+
+    #
+    # The subclasses we have.
+    #
+    @@subclasses = { }
+
+
+    #
+    # Create an alerter object, based upon the type
+    #
+    def self.create( alert_type, obj )
+
+      c = @@subclasses[alert_type]
+      if c
+        c.new( obj )
+      else
+        raise ArgumentError, "Bad alert type: '#{alert_type}'"
+      end
+    end
+
+
+    #
+    # Register a new test type - this must be called by our derived classes
+    #
+    def self.register_alert_type name
+      @@subclasses[name] = self
+    end
+
+
+    #
+    # Return an array of test-types we know about
+    #
+    # i.e. Derived classes that have registered themselves.
+    #
+    #
+    def self.known_alerters
+      @@subclasses
+    end
+
+
+
+    def raise
+      raise NoMethod, "This should be implemented in a derived class"
+    end
+
+
+
+    def clear
+      raise NoMethod, "This should be implemented in a derived class"
+    end
+  end
+
+end