Callbacks proxy

README.md

@@ -139,6 +139,17 @@ person.morning.value = "blue"                        # => SET people:1:morning
 true == person.morning.blue?                         # => GET people:1:morning
 ```
 
+You can also define `after_change` callbacks that trigger on mutations:
+
+```ruby
+class Person < ApplicationRecord
+  kredis_list :names, after_change: ->(p) {  }
+  kredis_unique_list :skills, limit: 2, after_change: :skillset_changed
+
+  def skillset_changed(p)
+  end
+end
+```
 
 ## Installation
 

lib/kredis.rb

@@ -8,6 +8,7 @@
 require "kredis/type_casting"
 require "kredis/types"
 require "kredis/attributes"
+require "kredis/callbacks_proxy"
 
 require "kredis/railtie" if defined?(Rails::Railtie)
 

lib/kredis/attributes.rb

@@ -2,76 +2,82 @@ module Kredis::Attributes
   extend ActiveSupport::Concern
 
   class_methods do
-    def kredis_proxy(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_proxy(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_string(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_string(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_integer(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_integer(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_decimal(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_decimal(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_datetime(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_datetime(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_flag(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_flag(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
 
       define_method("#{name}?") do
         send(name).marked?
       end
     end
 
-    def kredis_enum(name, key: nil, values:, default:, config: :shared)
-      kredis_connection_with __method__, name, key, values: values, default: default, config: config
+    def kredis_enum(name, key: nil, values:, default:, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, values: values, default: default, config: config, after_change: after_change
     end
 
-    def kredis_json(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_json(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_list(name, key: nil, typed: :string, config: :shared)
-      kredis_connection_with __method__, name, key, typed: typed, config: config
+    def kredis_list(name, key: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_unique_list(name, limit: nil, key: nil, typed: :string, config: :shared)
-      kredis_connection_with __method__, name, key, limit: limit, typed: typed, config: config
+    def kredis_unique_list(name, limit: nil, key: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, limit: limit, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_set(name, key: nil, typed: :string, config: :shared)
-      kredis_connection_with __method__, name, key, typed: typed, config: config
+    def kredis_set(name, key: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_slot(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_slot(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
-    def kredis_slots(name, available:, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, available: available, config: config
+    def kredis_slots(name, available:, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, available: available, config: config, after_change: after_change
     end
 
-    def kredis_counter(name, key: nil, config: :shared)
-      kredis_connection_with __method__, name, key, config: config
+    def kredis_counter(name, key: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, config: config, after_change: after_change
     end
 
     private
       def kredis_connection_with(method, name, key, **options)
         ivar_symbol = :"@#{name}_#{method}"
         type = method.to_s.sub("kredis_", "")
+        callback = options.delete(:after_change)
 
         define_method(name) do
           if instance_variable_defined?(ivar_symbol)
             instance_variable_get(ivar_symbol)
           else
-            instance_variable_set(ivar_symbol, Kredis.send(type, kredis_key_evaluated(key) || kredis_key_for_attribute(name), **options))
+            instance_variable_set(ivar_symbol,
+                                  Kredis::CallbacksProxy.new(
+                                    Kredis.send(type, kredis_key_evaluated(key) || kredis_key_for_attribute(name), **options),
+                                    self,
+                                    callback)
+                                 )
           end
         end
       end

lib/kredis/callbacks_proxy.rb

@@ -0,0 +1,22 @@
+class Kredis::CallbacksProxy
+  attr_reader :type
+  delegate :to_s, to: :type
+
+  def initialize(type, record, callback)
+    @type, @record, @callback = type, record, callback
+  end
+
+  def method_missing(method, *args, **kwargs, &block)
+    result = @type.send(method, *args, **kwargs, &block)
+
+    if @type.callback_operations&.include? method
+      if @callback.respond_to? :call
+        @callback.call(@record, @type)
+      elsif @callback.is_a? Symbol
+        @record.send(@callback, @record, @type)
+      end
+    end
+
+    result
+  end
+end

lib/kredis/types/counter.rb

@@ -3,6 +3,10 @@ class Kredis::Types::Counter < Kredis::Types::Proxying
 
   attr_accessor :expires_in
 
+  def callback_operations
+    %i[increment decrement reset].freeze
+  end
+
   def increment(by: 1)
     multi do
       set 0, ex: expires_in, nx: true

lib/kredis/types/cycle.rb

@@ -1,6 +1,10 @@
 class Kredis::Types::Cycle < Kredis::Types::Counter
   attr_accessor :values
 
+  def callback_operations
+    %i[next].freeze
+  end
+
   alias index value
 
   def value

lib/kredis/types/enum.rb

@@ -3,6 +3,10 @@ class Kredis::Types::Enum < Kredis::Types::Proxying
 
   attr_accessor :values, :default
 
+  def callback_operations
+    %i[value= reset].freeze
+  end
+
   def initialize(...)
     super
     define_predicates_for_values

lib/kredis/types/flag.rb

@@ -1,6 +1,10 @@
 class Kredis::Types::Flag < Kredis::Types::Proxying
   proxying :set, :exists?, :del
 
+  def callback_operations
+    %i[mark remove].freeze
+  end
+
   def mark(expires_in: nil)
     set 1, ex: expires_in
   end

lib/kredis/types/list.rb

@@ -3,6 +3,10 @@ class Kredis::Types::List < Kredis::Types::Proxying
 
   attr_accessor :typed
 
+  def callback_operations
+    %i[remove prepend append].freeze
+  end
+
   def elements
     strings_to_types(lrange(0, -1) || [], typed)
   end

lib/kredis/types/scalar.rb

@@ -3,6 +3,10 @@ class Kredis::Types::Scalar < Kredis::Types::Proxying
 
   attr_accessor :typed, :default
 
+  def callback_operations
+    %i[value= clear].freeze
+  end
+
   def value=(value)
     set type_to_string(value)
   end

lib/kredis/types/set.rb

@@ -3,6 +3,10 @@ class Kredis::Types::Set < Kredis::Types::Proxying
 
   attr_accessor :typed
 
+  def callback_operations
+    %i[add remove replace take clear].freeze
+  end
+
   def members
     strings_to_types(smembers || [], typed).sort
   end

lib/kredis/types/slots.rb

@@ -5,6 +5,10 @@ class NotAvailable < StandardError; end
 
   attr_accessor :available
 
+  def callback_operations
+    %i[reserve release reset].freeze
+  end
+
   def reserve
     failsafe returning: false do
       if block_given?