Merge pull request #61 from aderyabin/using_block

Add Blocks support

README.md

@@ -80,7 +80,10 @@ end
 
 class Atom
   include SAXMachine
-  element :title
+  # Using block handle custom parsing behavior
+  element :title do |title|
+    title.strip
+  end
   # The :with argument means that you only match a link tag
   # that has an attribute of type: "text/html"
   element :link, value: :href, as: :url, with: {

lib/sax-machine/sax_document.rb

@@ -39,16 +39,16 @@ def parse(*args)
       new.parse(*args)
     end
 
-    def element(name, options = {})
+    def element(name, options = {}, &block)
       real_name = (options[:as] ||= name).to_s
       sax_config.add_top_level_element(name, options)
-      create_attr(real_name)
+      create_attr(real_name, &block)
     end
 
-    def attribute(name, options = {})
+    def attribute(name, options = {}, &block)
       real_name = (options[:as] ||= name).to_s
       sax_config.add_top_level_attribute(self.class.to_s, options.merge(name: name))
-      create_attr(real_name)
+      create_attr(real_name, &block)
     end
 
     def value(name, options = {})
@@ -115,9 +115,18 @@ def sax_config
     # we only want to insert the getter and setter if they haven't defined it from elsewhere.
     # this is how we allow custom parsing behavior. So you could define the setter
     # and have it parse the string into a date or whatever.
-    def create_attr(real_name)
+    def create_attr(real_name, &block)
       attr_reader(real_name) unless method_defined?(real_name)
-      attr_writer(real_name) unless method_defined?("#{real_name}=")
+
+      if !method_defined?("#{real_name}=")
+        if block_given?
+          define_method("#{real_name}=") do |value|
+             instance_variable_set("@#{real_name}", (yield value))
+          end
+        else
+          attr_writer(real_name)
+        end
+      end
     end
   end
 end

spec/sax-machine/sax_document_spec.rb

@@ -218,6 +218,41 @@ def title=(val)
           expect(@klass.required?(:date)).to be_truthy
         end
       end
+
+      describe "the block" do
+        before do
+          @klass = Class.new do
+            include SAXMachine
+
+            element :title do  |title|
+              "#{title}!!!"
+            end
+
+            attribute :id do |id|
+              id.to_i
+            end
+
+            element :link, value: :foo do |link|
+              link.downcase
+            end
+          end
+        end
+
+        it "handle element" do
+          document = @klass.parse("<title>SAX</title>")
+          expect(document.title).to eq("SAX!!!")
+        end
+
+        it 'handle attribute' do
+          document = @klass.parse("<title id='345'>SAX</title>")
+          expect(document.id).to eq(345)
+        end
+
+        it "handle attribute value" do
+          document = @klass.parse("<link foo='tEst'>hello</link>")
+          expect(document.link).to eq("test")
+        end
+      end
     end
 
     describe "when parsing multiple elements" do