Added support for an unless condition.

lib/breadcrumb.rb

@@ -4,8 +4,13 @@ class Breadcrumb
   include Singleton
   Trail = Struct.new(:controller, :action, :trail, :options) do
     def condition_met?(obj)
-      condition = options[:if]
-      condition.nil? or obj.send(condition)
+      if options[:if]
+        obj.send(options[:if])
+      elsif options[:unless]
+        !obj.send(options[:unless])
+      else
+        true
+      end
     end
   end
 

spec/breadcrumbs_helper_spec.rb

@@ -176,7 +176,7 @@ def its_true!
       crumbs.should == %Q{<a href="http://test.host/search/new">Search Results ()</a>}
     end
 
-    it "should not consider a trail when it has a condition and it's not met" do
+    it "should not consider a trail when it has an :if condition and it's not met" do
       Breadcrumb.configure do
         crumb :search_results, 'Search Results', :current
         trail :search, [:create, :new], [:search_results], :if => :is_it_false?
@@ -187,7 +187,7 @@ def its_true!
       crumbs.should == ""
     end
 
-    it "should consider a trail when it has a condition and it's met" do
+    it "should consider a trail when it has an :if condition and it's met" do
       Breadcrumb.configure do
         crumb :search_results, 'Search Results', :current
         trail :search, [:create, :new], [:search_results], :if => :its_true!
@@ -197,6 +197,28 @@ def its_true!
       params[:action] = 'new'
       crumbs.should == %Q{<a href="http://test.host/search/new">Search Results</a>}
     end
+
+    it "should not consider a trail when it has an :unless condition and it's not met" do
+      Breadcrumb.configure do
+        crumb :search_results, 'Search Results', :current
+        trail :search, [:create, :new], [:search_results], :unless => :its_true!
+      end
+
+      params[:controller] = 'search'
+      params[:action] = 'new'
+      crumbs.should == ""
+    end
+
+    it "should consider a trail when it has an :unless condition and it's met" do
+      Breadcrumb.configure do
+        crumb :search_results, 'Search Results', :current
+        trail :search, [:create, :new], [:search_results], :unless => :is_it_false?
+      end
+
+      params[:controller] = 'search'
+      params[:action] = 'new'
+      crumbs.should == %Q{<a href="http://test.host/search/new">Search Results</a>}
+    end
 
     describe "when fetching parameters" do
       it "should support nested parameter attributes" do