ActionView::BaseAction View Base Action View templates can be written in several ways. If the template file has a .erb extension, then it uses the erubi template system which can embed Ruby into an HTML document. If the template file has a .builder extension, then Jim Weirich’s Builder::XmlMarkup library is used. ERB You trigger ERB by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used
