def opf
      @opf_metainfo = opf_metainfo
      @opf_coverimage = opf_coverimage
      @opf_manifest = opf_manifest
      @opf_toc = opf_tocx

      tmplfile = File.expand_path('./opf/epubv2.opf.erb', ReVIEW::Template::TEMPLATE_DIR)
      tmpl = ReVIEW::Template.load(tmplfile)
      tmpl.result(binding)
    end
def opf
      @opf_metainfo = opf_metainfo
      @opf_coverimage = opf_coverimage
      @opf_manifest = opf_manifest
      @opf_toc = opf_tocx

      tmplfile = File.expand_path('./opf/epubv2.opf.erb', ReVIEW::Template::TEMPLATE_DIR)
      tmpl = ReVIEW::Template.load(tmplfile)
      tmpl.result(binding)
    end
Construct object with parameter hash +config+ and message resource hash +res+.
 Return opf file content.