allow for passing handler responsibility to the next handler

lib/blather/client/client.rb

@@ -131,16 +131,17 @@ def handle_stanza(stanza)
     end
 
     def call_handler_for(type, stanza)
-      if @handlers[type]
-        @handlers[type].find do |guards, handler|
-          if guards.first.is_a?(String)
-            unless (result = stanza.find(*guards)).empty?
-              handler.call(stanza, result)
-            end
-          elsif !guarded?(guards, stanza)
-            handler.call(stanza)
-          end
-        end
+      return unless handler = @handlers[type]
+      handler.find do |guards, handler|
+        catch(:pass) { call_handler handler, guards, stanza }
+      end
+    end
+
+    def call_handler(handler, guards, stanza)
+      if guards.first.respond_to?(:to_str) && !(result = stanza.find(*guards)).empty?
+        handler.call(stanza, result)
+      elsif !guarded?(guards, stanza)
+        handler.call(stanza)
       end
     end
 

lib/blather/client/dsl.rb

@@ -82,6 +82,18 @@ def jid
       client.jid
     end
 
+    ##
+    # Halt the handler chain
+    def halt
+      throw :halt
+    end
+
+    ##
+    # Pass responsibility to the next handler
+    def pass
+      throw :pass
+    end
+
     ##
     # Request items or info from an entity
     #   discover (items|info), [jid], [node] do |response|

spec/blather/client/client_spec.rb

@@ -117,13 +117,38 @@
 
   it 'allows for breaking out of handlers' do
     stanza = Blather::Stanza::Iq.new
-    response = mock()
-    response.expects(:call).times(1)
+    response = mock(:iq => nil)
     @client.register_handler(:iq) do |_|
-      response.call
+      response.iq
       throw :halt
-      response.call
+      response.fail
+    end
+    @client.receive_data stanza
+  end
+
+  it 'allows for passing to the next handler of the same type' do
+    stanza = Blather::Stanza::Iq.new
+    response = mock(:iq1 => nil, :iq2 => nil)
+    @client.register_handler(:iq) do |_|
+      response.iq1
+      throw :pass
+      response.fail
+    end
+    @client.register_handler(:iq) do |_|
+      response.iq2
+    end
+    @client.receive_data stanza
+  end
+
+  it 'allows for passing to the next handler in the heirarchy' do
+    stanza = Blather::Stanza::Iq::Query.new
+    response = mock(:query => nil, :iq => nil)
+    @client.register_handler(:query) do |_|
+      response.query
+      throw :pass
+      response.fail
     end
+    @client.register_handler(:iq) { |_| response.iq }
     @client.receive_data stanza
   end
 end

spec/blather/client/dsl_spec.rb

@@ -31,6 +31,14 @@
     @dsl.shutdown
   end
 
+  it 'can throw a halt' do
+    catch(:halt) { @dsl.halt }
+  end
+
+  it 'can throw a pass' do
+    catch(:pass) { @dsl.pass }
+  end
+
   it 'sets up handlers' do
     type = :message
     guards = [:chat?, {:body => 'exit'}]