16222 - Add fetch function for request object in agents

This commit adds a fetch method to both the request and result objects
that will help users create more deterministic code in the face of
missing data

lib/mcollective/rpc/reply.rb

@@ -69,6 +69,10 @@ def [](key)
         @data[key]
       end
 
+      def fetch(key, default)
+        @data.fetch(key, default)
+      end
+
       # Returns a compliant Hash of the reply that should be sent
       # over the middleware
       def to_hash

lib/mcollective/rpc/request.rb

@@ -36,6 +36,11 @@ def [](key)
         return @data[key]
       end
 
+      def fetch(key, default)
+        return nil unless @data.is_a?(Hash)
+        return @data.fetch(key, default)
+      end
+
       def to_hash
         return {:agent => @agent,
                 :action => @action,

lib/mcollective/rpc/result.rb

@@ -24,6 +24,10 @@ def []=(idx, item)
         @results[idx] = item
       end
 
+      def fetch(key, default)
+        @results.fetch(key, default)
+      end
+
       def each
         @results.each_pair {|k,v| yield(k,v) }
       end

spec/unit/rpc/request_spec.rb

@@ -100,6 +100,18 @@ module RPC
         end
       end
 
+      describe "#fetch" do
+        it "should return nil for non hash data" do
+          @req[:body][:data] = "foo"
+          Request.new(@req, @ddl)["foo"].should == nil
+        end
+
+        it "should fetch data with the correct default behavior" do
+          @request.fetch(:foo, "default").should == "bar"
+          @request.fetch(:rspec, "default").should == "default"
+        end
+      end
+
       describe "#to_hash" do
         it "should have the correct keys" do
           @request.to_hash.keys.sort.should == [:action, :agent, :data]

spec/unit/rpc/result_spec.rb

@@ -44,6 +44,13 @@ module RPC
         end
       end
 
+      describe "#fetch" do
+        it "should fetch data with the correct default behavior" do
+          @result.fetch(:foo, "default").should == "bar"
+          @result.fetch(:rspec, "default").should == "default"
+        end
+      end
+
       describe "#each" do
         it "should itterate all the pairs" do
           data = {}

website/changelog.md

@@ -8,6 +8,7 @@ toc: false
 
 |Date|Description|Ticket|
 |----|-----------|------|
+|2012/09/04|Add a fetch method that mimic Hash#fetch to RPC Results and Requests|16222|
 |2012/09/04|Include the required mcollective version in packages that include the requirement|16173|
 |2012/08/29|Add a RabbitMQ specific connector plugin|16168|
 |2012/08/22|DDL files can now specify which is the minimal version of mcollective they require|15850|