This class implements the basic controller for data groupings in Ruport (a collection of Groups).

Supported Formatters

• Formatter::CSV
• Formatter::Text
• Formatter::HTML
• Formatter::PDF

Default layout options

• show_group_headers #=> true
• style #=> :inline

Formatter hooks called (in order)

• build_grouping_header
• build_grouping_body
• build_grouping_footer
• finalize_grouping