= reverse_asciidoctor Based on https://github.com/xijo/reverse_markdown Transforms HTML into asciidoctor. == Requirements . http://nokogiri.org/[Nokogiri] . Ruby 1.9.3 or higher == Installation Install the gem [source,console] ---- [sudo] gem install reverse_asciidoctor ---- or add it to your Gemfile [source,ruby] ---- gem 'reverse_asciidoctor' ---- == Features As a port of reverse_markdown, reverse_asciidoctor shares its features: * Module based - if you miss a tag, just add it * Can deal with nested lists * Inline and block code is supported * Supports blockquote It supports the following html tags supported by reverse_markdown: * `a` * `blockquote` * `br` * `code`, `tt` (added: `kbd`, `samp`, `var`) * `div`, `article` * `em`, `i` (added: `cite`) * `h1`, `h2`, `h3`, `h4`, `h5`, `h6`, `hr` * `img` * `li`, `ol`, `ul` (added: `dir`) * `p`, `pre` * `strong`, `b` * `table`, `td`, `th`, `tr` [NOTE] ==== * reverse_asciidoctor does *not* support `del` or `strike`, because Asciidoctor out of the box does not * As with reverse_markdown, `pre` is only treated as sourcecode if it is contained in a `div@class = highlight-` element, or has a `@brush` attribute naming the language (Confluence). * The gem does not support `p@align`, because Asciidoctor doesn't ==== In addition, it supports: * `aside` * `audio`, `video` (with `@src` attributes) * `figure`, `figcaption` * `mark` * `q` * `sub`, `sup` * `@id` anchors * `blockquote@cite` * `img/@width`, `img/@height` * `ol/@style`, `ol/@start`, `ol/@reversed`, `ul/@type` * `td/@colspan`, `td/@rowspan`, `td@/align`, `td@/valign` * `table/caption`, `table/@width`, `table/@frame` (partial), `table/@rules` (partial) * Lists and paragraphs within cells ** Not tables within cells: Asciidoctor cannot deal with nested tabls It also supports MathML... sort of. * Asciidoctor supports AsciiMath and LaTeX for stem expressions. HTML uses MathML. The gem will recognise MathML expressions in HTML, and will wrap them in Asciidoctor `stem:[ ]` macros. The result of this gem is not actually legal Asciidoctor for stem: Asciidoctor will presumably think this is AsciiMath in the `stem:[ ]` macro, try to pass it into MathJax as AsciiMath, and fail. But of course, MathJax has no problem with MathML, and some postprocessing on the Asciidoctor output can ensure that the MathML is treated by MathJax (or whatever else uses the output) as such; so this is still much better than nothing for stem processing. * An alternative would be to attempt to map MathML to either LaTeX or AsciiMath. ** The self-description of https://github.com/learningobjectsinc/mathml-to-asciimath ("subset"... "this module is not: comprehensive, performant") does not recommend it, when MathJax is entirely happy with MathML anyway. ** https://github.com/transpect/mml2tex looks rather more robust, and is also used to export Word documents and their OOMML to LaTeX via MathML. But we'd still rather keep the MathML in place. The gem does not support: * `col`, `colgroup` * `source`, `picture` * `bdi`, `bdo`, `ruby`, `rt`, `rp`, `wbr` * `frame`, `frameset`, `iframe`, `noframes`, `noscript`, `script`, `input`, `output`, `progress` * `map`, `canvas`, `dialog`, `embed`, `object`, `param`, `svg`, `track` * `fieldset`, `button`, `datalist`, `form`, `label`, `legend`, `menu`, `menulist`, `optgroup`, `option`, `select`, `textarea` * `big`, `dfn`, `font`, `s`, `small`, `span`, `strike`, `u` * `center` * `data`, `meter` * `del`, `ins` * `footer`, `header`, `main`, `nav`, `details`, `section`, `summary`, `template` == Usage === Ruby You can convert html content as string or Nokogiri document: [source,ruby] ---- input = 'feelings' result = ReverseAsciidoctor.convert input result.inspect # " *feelings* " ---- === Commandline It's also possible to convert html files to markdown using the binary: [source,console] ---- $ bin/reverse_asciidoctor file.html > file.adoc $ cat file.html | bin/reverse_asciidoctor > file.adoc ---- In addition, the `bin/w2a` script (adapted from the `bin/w2m` script in https://github.com/benbalter/word-to-markdown[Ben Balter's word-to-markdown]) extracts HTML from Word docx documents, and converts it to Asciidoc. [source,console] ---- $ bundle exec bin/w2a document.docx > document.adoc ---- The script presumes that LibreOffice has already been installed: it uses LibreOffice's export to XHTML. LibreOffice's export of XHTML is superior to the native Microsoft Word export to HTML: it exports lists (which Word keeps as paragraphs), and it exports OOMML into MathML. On the other hand, the LibreOffice export relies on default styling being used in the document, and it may not cope with ordered lists or headings with customised appearance. For best results, reset the styles in the document you're converting to those in the default Normal.dot template. === Configuration The following options are available: * `unknown_tags` (default `pass_through`) - how to handle unknown tags. Valid options are: ** `pass_through` - Include the unknown tag completely into the result ** `drop` - Drop the unknown tag and its content ** `bypass` - Ignore the unknown tag but try to convert its content ** `raise` - Raise an error to let you know * `tag_border` (default `' '`) - how to handle tag borders. valid options are: ** `' '` - Add whitespace if there is none at tag borders. ** `''` - Do not not add whitespace. ==== As options Just pass your chosen configuration options in after the input. The given options will last for this operation only. [source,ruby] ---- ReverseAsciidoctor.convert(input, unknown_tags: :raise) ---- ==== Preconfigure Or configure it block style on a initializer level. These configurations will last for all conversions until they are set to something different. [source,ruby] ---- ReverseAsciidoctor.config do |config| config.unknown_tags = :bypass config.github_flavored = true config.tag_border = '' end ---- == Related stuff * https://github.com/xijo/reverse_markdown[Xijo's original reverse_markdown gem] * https://github.com/xijo/reverse_markdown/wiki/Write-your-own-converter[Write custom converters] - Wiki entry about how to write your own converter * https://github.com/harlantwood/html_massage[html_massage] - A gem by Harlan T. Wood to convert regular sites into markdown using reverse_markdown * https://github.com/benbalter/word-to-markdown[word-to-markdown] - Convert word docs into markdown while using reverse_markdown, by Ben Balter * https://github.com/asciidocfx/HtmlToAsciidoc[HtmlToAsciidoc] - Javascript regexp-based converter of HTML to Asciidoctor * https://asciidoctor.org/docs/user-manual/[The Asciidoctor User Manual]