Validating quality

lib/encoding_dot_com/image_format.rb

@@ -13,6 +13,7 @@ def initialize(attributes={})
     def validate_attributes
       validate_image_format
       validate_resize_method
+      validate_quality
     end
 
     def validate_image_format
@@ -26,6 +27,11 @@ def validate_resize_method
         raise IllegalFormatAttribute.new("resize_method should be one of resize, crop or combine.")
       end
     end
-
+
+    def validate_quality
+      unless quality.nil? || (quality.to_i >= 1 && quality.to_i <= 100)
+        raise IllegalFormatAttribute.new("quality should be between 1 and 100.")
+      end
+    end
   end
 end

spec/image_format_spec.rb

@@ -30,27 +30,38 @@
     format_xml("keep_aspect_ratio" => true).should have_xpath("/format/keep_aspect_ratio[text()='yes']")
   end
 
-  describe "valid attributes" do
+  describe "valid resize method" do
     %w{resize crop combine}.each do |method|
-      it "should allow '#{method}' as a resize_method" do
+      it "should allow '#{method}'" do
         lambda { format_xml("resize_method" => method) }.should_not raise_error(EncodingDotCom::IllegalFormatAttribute)
       end
     end
 
-    it "should not allow anything else as a resize_method" do
+    it "should not allow anything else" do
       lambda { format_xml("resize_method" => "foo") }.should raise_error(EncodingDotCom::IllegalFormatAttribute)
     end
+  end
 
+  describe "valid image format" do
     %w{jpg png gif}.each do |format|
-      it "should allow '#{format}' as an image_format" do
+      it "should allow '#{format}'" do
         lambda { format_xml("image_format" => format) }.should_not raise_error(EncodingDotCom::IllegalFormatAttribute)
       end
     end
 
-    it "should not allow anything else as an image_format" do
+    it "should not allow anything else" do
       lambda { format_xml("image_format" => "foo") }.should raise_error(EncodingDotCom::IllegalFormatAttribute)
     end
   end
+
+  describe "valid quality" do
+    it "should be between 1 and 100" do
+      lambda { format_xml("quality" => 0) }.should raise_error(EncodingDotCom::IllegalFormatAttribute)
+      lambda { format_xml("quality" => 101) }.should raise_error(EncodingDotCom::IllegalFormatAttribute)
+      lambda { format_xml("quality" => 1) }.should_not raise_error(EncodingDotCom::IllegalFormatAttribute)      
+      lambda { format_xml("quality" => 100) }.should_not raise_error(EncodingDotCom::IllegalFormatAttribute)      
+    end
+  end
 
   def format_xml(attributes={})
     format = EncodingDotCom::ImageFormat.new(attributes)