# File lib/action_view/helpers/asset_tag_helper.rb, line 628 def image_tag(source, options = {}) options.symbolize_keys! src = options[:src] = path_to_image(source) unless src =~ /^cid:/ options[:alt] = options.fetch(:alt){ File.basename(src, '.*').capitalize } end if size = options.delete(:size) options[:width], options[:height] = size.split("x") if size =~ %r{^\d+x\d+$} end if mouseover = options.delete(:mouseover) options[:onmouseover] = "this.src='#{path_to_image(mouseover)}'" options[:onmouseout] = "this.src='#{src}'" end tag("img", options) end