1 files changed, 147 insertions, 0 deletions
diff --git a/actionview/lib/action_view/helpers/tags/base.rb b/actionview/lib/action_view/helpers/tags/base.rb
new file mode 100644
index 0000000000..3fe3f4e9df
--- /dev/null
+++ b/actionview/lib/action_view/helpers/tags/base.rb
@@ -0,0 +1,147 @@
+module ActionView
+  module Helpers
+    module Tags # :nodoc:
+      class Base # :nodoc:
+        include Helpers::ActiveModelInstanceTag, Helpers::TagHelper, Helpers::FormTagHelper
+        include FormOptionsHelper
+
+        attr_reader :object
+
+        def initialize(object_name, method_name, template_object, options = {})
+          @object_name, @method_name = object_name.to_s.dup, method_name.to_s.dup
+          @template_object = template_object
+
+          @object_name.sub!(/\[\]$/,"") || @object_name.sub!(/\[\]\]$/,"]")
+          @object = retrieve_object(options.delete(:object))
+          @options = options
+          @auto_index = retrieve_autoindex(Regexp.last_match.pre_match) if Regexp.last_match
+        end
+
+        # This is what child classes implement.
+        def render
+          raise NotImplementedError, "Subclasses must implement a render method"
+        end
+
+        private
+
+        def value(object)
+          object.send @method_name if object
+        end
+
+        def value_before_type_cast(object)
+          unless object.nil?
+            method_before_type_cast = @method_name + "_before_type_cast"
+
+            object.respond_to?(method_before_type_cast) ?
+              object.send(method_before_type_cast) :
+              value(object)
+          end
+        end
+
+        def retrieve_object(object)
+          if object
+            object
+          elsif @template_object.instance_variable_defined?("@#{@object_name}")
+            @template_object.instance_variable_get("@#{@object_name}")
+          end
+        rescue NameError
+          # As @object_name may contain the nested syntax (item[subobject]) we need to fallback to nil.
+          nil
+        end
+
+        def retrieve_autoindex(pre_match)
+          object = self.object || @template_object.instance_variable_get("@#{pre_match}")
+          if object && object.respond_to?(:to_param)
+            object.to_param
+          else
+            raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to to_param: #{object.inspect}"
+          end
+        end
+
+        def add_default_name_and_id_for_value(tag_value, options)
+          if tag_value.nil?
+            add_default_name_and_id(options)
+          else
+            specified_id = options["id"]
+            add_default_name_and_id(options)
+
+            if specified_id.blank? && options["id"].present?
+              options["id"] += "_#{sanitized_value(tag_value)}"
+            end
+          end
+        end
+
+        def add_default_name_and_id(options)
+          if options.has_key?("index")
+            options["name"] ||= options.fetch("name"){ tag_name_with_index(options["index"], options["multiple"]) }
+            options["id"] = options.fetch("id"){ tag_id_with_index(options["index"]) }
+            options.delete("index")
+          elsif defined?(@auto_index)
+            options["name"] ||= options.fetch("name"){ tag_name_with_index(@auto_index, options["multiple"]) }
+            options["id"] = options.fetch("id"){ tag_id_with_index(@auto_index) }
+          else
+            options["name"] ||= options.fetch("name"){ tag_name(options["multiple"]) }
+            options["id"] = options.fetch("id"){ tag_id }
+          end
+
+          options["id"] = [options.delete('namespace'), options["id"]].compact.join("_").presence
+        end
+
+        def tag_name(multiple = false)
+          "#{@object_name}[#{sanitized_method_name}]#{"[]" if multiple}"
+        end
+
+        def tag_name_with_index(index, multiple = false)
+          "#{@object_name}[#{index}][#{sanitized_method_name}]#{"[]" if multiple}"
+        end
+
+        def tag_id
+          "#{sanitized_object_name}_#{sanitized_method_name}"
+        end
+
+        def tag_id_with_index(index)
+          "#{sanitized_object_name}_#{index}_#{sanitized_method_name}"
+        end
+
+        def sanitized_object_name
+          @sanitized_object_name ||= @object_name.gsub(/\]\[|[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "")
+        end
+
+        def sanitized_method_name
+          @sanitized_method_name ||= @method_name.sub(/\?$/,"")
+        end
+
+        def sanitized_value(value)
+          value.to_s.gsub(/\s/, "_").gsub(/[^-\w]/, "").downcase
+        end
+
+        def select_content_tag(option_tags, options, html_options)
+          html_options = html_options.stringify_keys
+          add_default_name_and_id(html_options)
+          options[:include_blank] ||= true unless options[:prompt] || select_not_required?(html_options)
+          select = content_tag("select", add_options(option_tags, options, value(object)), html_options)
+
+          if html_options["multiple"] && options.fetch(:include_hidden, true)
+            tag("input", :disabled => html_options["disabled"], :name => html_options["name"], :type => "hidden", :value => "") + select
+          else
+            select
+          end
+        end
+
+        def select_not_required?(html_options)
+          !html_options["required"] || html_options["multiple"] || html_options["size"].to_i > 1
+        end
+
+        def add_options(option_tags, options, value = nil)
+          if options[:include_blank]
+            option_tags = content_tag_string('option', options[:include_blank].kind_of?(String) ? options[:include_blank] : nil, :value => '') + "\n" + option_tags
+          end
+          if value.blank? && options[:prompt]
+            option_tags = content_tag_string('option', prompt_text(options[:prompt]), :value => '') + "\n" + option_tags
+          end
+          option_tags
+        end
+      end
+    end
+  end
+end