1 files changed, 112 insertions, 0 deletions
diff --git a/app/lib/dev/events.rb b/app/lib/dev/events.rb
new file mode 100644
index 0000000..c891ef5
--- /dev/null
+++ b/app/lib/dev/events.rb
@@ -0,0 +1,112 @@
+module HH; end
+
+class HH::EventConnection
+#  module Array
+#    def ===(other)
+#      return false unless other.is_a? ::Array
+#      (0...size).each do |i|
+#        cond = self[i]
+#        return false unless cond == :any || cond === other[i]
+#      end
+#      return false
+#    end
+#  end
+
+  attr_reader :event
+  
+  def initialize event, args_cond, &blk
+    @event, @args_cond, @blk = event, args_cond, blk
+  end
+
+  # executes the connection if the arguments match
+  def try args
+    # the argument conditions matched
+    @blk.call *args if match? args
+  end
+
+private
+  # checks if the arguments +args+ match the conditions +@args_cond+
+  def match? args
+    # match size
+    return false if @args_cond.size != args.size
+
+    if @args_cond.size == 1 && @args_cond[0].is_a?(Hash)
+      return self.class.match_hash?(@args_cond[0], args[0])
+    end
+
+    # else match each element
+    (0...args.size).each do |i|
+      cond = @args_cond[i]
+      return false unless cond == :any || cond === args[i]
+    end
+    return true
+  end
+
+  def self.match_hash?(cond, hash)
+    cond.is_a?(Hash) or raise ArgumentError
+    return false unless hash.is_a?(Hash)
+    cond.each do |key, cond|
+      return false unless cond === hash[key]
+    end
+    return true
+  end
+
+#  def observer
+#    @blk.binding.eval("self")
+#  end
+
+public
+  def to_s
+    "#<EventConnection :#{@event} #{@args_cond.inspect}] >"
+  end
+
+  alias inspect to_s
+end
+
+
+class HH::EventCondition
+  def initialize &blk
+    @blk = blk
+  end
+
+  def === args
+    if not args.is_a? Hash
+      raise ArgumentError, "for now EventCondition only works on hash events"
+    end
+    @blk.call args# && match_hash?(args, {})
+  end
+
+#private
+#  def simple_condition_match? args
+#    HH::EventConnection.match_hash?(@simple_condition, hash)
+#  end
+end
+
+
+require 'set'
+
+module HH::Observable
+  def emit event, *args
+    return unless @event_connections
+    connections = @event_connections[event]
+    connections.each {|c| c.try(args)}
+  end
+
+  # :any is a condition that always matches
+  # returns the new connection (that can be useful later to delete it)
+  def on_event event, *args_cond, &blk
+    # in first call initialize @event_connections
+    @event_connections = Hash.new(Set.new) if @event_connections.nil?
+    new_conn = HH::EventConnection.new event, args_cond, &blk
+    @event_connections[event] += [new_conn]
+    #debug "#{new_conn} added"
+    #emit :new_event_connection, new_conn
+    new_conn
+  end
+
+  def delete_event_connection c
+    #debug "#{c} deleted!"
+    @event_connections[c.event].delete c
+  end
+end
+