Add option to not exclude _html fields from attributes

app/models/concerns/cache_markdown_field.rb

@@ -7,6 +7,7 @@
 #     cache_markdown_field :foo
 #     cache_markdown_field :bar
 #     cache_markdown_field :baz, pipeline: :single_line
+#     cache_markdown_field :baz, hidden: false
 #
 # Corresponding foo_html, bar_html and baz_html fields should exist.
 module CacheMarkdownField
@@ -37,7 +38,15 @@ module CacheMarkdownField
     end
 
     def html_fields
-      markdown_fields.map {|field| html_field(field) }
+      markdown_fields.map { |field| html_field(field) }
+    end
+
+    def hidden_html_fields
+      markdown_fields.each_with_object([]) do |field, fields|
+        if @data[field].fetch(:hidden, true)
+          fields << html_field(field)
+        end
+      end
     end
   end
 
@@ -149,13 +158,17 @@ module CacheMarkdownField
     alias_method :attributes_before_markdown_cache, :attributes
     def attributes
       attrs = attributes_before_markdown_cache
+      html_fields = cached_markdown_fields.html_fields
+      hidden_html_fields = cached_markdown_fields.hidden_html_fields
 
-      attrs.delete('cached_markdown_version')
-
-      cached_markdown_fields.html_fields.each do |field|
+      hidden_html_fields.each do |field|
         attrs.delete(field)
       end
 
+      if (html_fields - hidden_html_fields).empty?
+        attrs.delete('cached_markdown_version')
+      end
+
       attrs
     end
 

spec/models/concerns/cache_markdown_field_spec.rb

@@ -23,6 +23,7 @@ describe CacheMarkdownField do
     include CacheMarkdownField
     cache_markdown_field :foo
     cache_markdown_field :baz, pipeline: :single_line
+    cache_markdown_field :zoo, hidden: false
 
     def self.add_attr(name)
       self.attribute_names += [name]
@@ -35,7 +36,7 @@ describe CacheMarkdownField do
 
     add_attr :cached_markdown_version
 
-    [:foo, :foo_html, :bar, :baz, :baz_html].each do |name|
+    [:foo, :foo_html, :bar, :baz, :baz_html, :zoo, :zoo_html].each do |name|
       add_attr(name)
     end
 
@@ -84,8 +85,8 @@ describe CacheMarkdownField do
   end
 
   describe '.attributes' do
-    it 'excludes cache attributes' do
-      expect(thing.attributes.keys.sort).to eq(%w[bar baz foo])
+    it 'excludes cache attributes that is hidden by default' do
+      expect(thing.attributes.keys.sort).to eq(%w[bar baz cached_markdown_version foo zoo zoo_html])
     end
   end
 
@@ -297,7 +298,12 @@ describe CacheMarkdownField do
     it 'saves the changes using #update_columns' do
       expect(thing).to receive(:persisted?).and_return(true)
       expect(thing).to receive(:update_columns)
-        .with("foo_html" => updated_html, "baz_html" => "", "cached_markdown_version" => cache_version)
+        .with(
+          "foo_html" => updated_html,
+          "baz_html" => "",
+          "zoo_html" => "",
+          "cached_markdown_version" => cache_version
+        )
 
       thing.refresh_markdown_cache!
     end