lastmodified accepts String and DateTime

lib/gepub/book.rb

@@ -68,7 +68,7 @@ module GEPUB
   # returns contributors list by display-seq or defined order.
   # the contributors without display-seq is appear after contributors with display-seq.
   # === Book#lastmodified(date) (delegated to Metadata#lastmodified)
-  # set last modified date.
+  # set last modified date. date is a Time, DateTime or string that can be parsed by DateTime#parse.
   # === Book#modified_now (delegated to Metadata#modified_now)
   # set last modified date to current time.
   # === Book#lastmodified (delegated to Metadata#lastmodified)

lib/gepub/metadata.rb

@@ -194,13 +194,14 @@ def lastmodified(date=UNASSIGNED)
       else
         @lastmodified_updated = true
         date ||= Time.now
+        date = DateTime.parse(date) if date.is_a? String
         (@content_nodes['meta'] ||= []).each {
           |meta|
           if (meta['property'] == 'dcterms:modified')
             @content_nodes['meta'].delete meta
           end
         }
-        add_metadata('meta', date.utc.strftime('%Y-%m-%dT%H:%M:%SZ'), itemclass: DateMeta)['property'] = 'dcterms:modified'
+        add_metadata('meta', date.to_time.utc.strftime('%Y-%m-%dT%H:%M:%SZ'), itemclass: DateMeta)['property'] = 'dcterms:modified'
       end
     end
 

spec/gepub_spec.rb

@@ -225,6 +225,18 @@
     end
   end
 
+
+  it 'should generate EPUB with specified lastmodified by string' do
+    epubname = File.join(File.dirname(__FILE__), 'testepub.epub')
+    mod_time = "2010-05-05T08:10:15Z"
+    @book.lastmodified = mod_time
+    @book.generate_epub(epubname)
+    File.open(epubname) do |f|
+      parsed_book = GEPUB::Book.parse(f)
+      expect(parsed_book.lastmodified.content).to eq mod_time
+    end
+  end
+
   it 'should generate parsed and generated EPUB with renewed lastmodified' do
     originalfile = File.join(File.dirname(__FILE__), 'fixtures/testdata/wasteland-20120118.epub')
     epubname = File.join(File.dirname(__FILE__), 'testepub.epub')