more xml parsing

lib/rsaml/assertion.rb

@@ -95,9 +95,8 @@ class Assertion
     # The subject of the statement(s) in the assertion.
     attr_accessor :subject
 
-    # Conditions that MUST be evaluated when assessing the validity of and/or when using the assertion.
-    #
-    # conditions should contain a single Conditions object
+    # Conditions that MUST be evaluated when assessing the validity of and/or when using the assertion. 
+    # Note: conditions should contain a single Conditions instance, not an array of Condition instances.
     attr_accessor :conditions
 
     # Construct a new assertion from the given issuer
@@ -170,6 +169,17 @@ def to_xml(xml=Builder::XmlMarkup.new)
       }
     end
 
+    # Construct an Action instance from the given XML Element or fragment.
+    def self.from_xml(element)
+      element = REXML::Document.new(element).root if element.is_a?(String)
+      issuer = Identifier::Issuer.from_xml(element.get_elements('saml:Issuer').first)
+      assertion = Assertion.new(issuer)
+      if (subject = element.get_elements('saml:Subject').first)
+        assertion.subject = Subject.from_xml(subject)
+      end
+      assertion
+    end
+
     protected
     def assertion_cache
       @assertion_cache ||= []

lib/rsaml/identifier/issuer.rb

@@ -17,6 +17,12 @@ def to_xml(xml=Builder::XmlMarkup.new)
         attributes['SPProvidedID'] = sp_provided_id unless sp_provided_id.nil?
         xml.tag!('saml:Issuer', value, attributes)
       end
+
+      # Construct an Issuer instance from the given XML Element or fragment.
+      def self.from_xml(element)
+        element = REXML::Document.new(element).root if element.is_a?(String)
+        Issuer.new(element.text)
+      end
     end
   end
 end

test/assertion_test.rb

@@ -102,6 +102,37 @@ class AssertionTest < Test::Unit::TestCase
         assert_match(/<saml:AuthnStatement AuthnInstant="#{date_match}"/, xml)
       end
     end
+
+    context "when consuming xml" do
+      should "return a valid Assertion instance" do
+        xml_fragment = %Q(
+          <saml:Assertion>
+            <saml:Issuer>Example</saml:Issuer>
+            <saml:Subject>Anthony</saml:Subject>
+          </saml:Assertion>
+        )
+        assertion = Assertion.from_xml(xml_fragment)
+        assert_not_nil assertion
+        assert_not_nil assertion.issuer
+        assert_equal 'Example', assertion.issuer.value
+        assert_nothing_raised do
+          assertion.validate
+        end
+      end
+      context "where there is no saml:Subject element" do
+        should "raise a validation error" do
+          xml_fragment = %Q(
+            <saml:Assertion>
+              <saml:Issuer>Example</saml:Issuer>
+            </saml:Assertion>
+          )
+          assertion = Assertion.from_xml(xml_fragment)
+          assert_raise ValidationError do
+            assertion.validate
+          end
+        end
+      end
+    end
   end
   context "an assertion URI ref" do
     setup do