Removed obsolete comment in emacs description.

[docutils.git] / FAQ.txt

.. -*- coding: utf-8 -*-

===========================================
 Docutils FAQ (Frequently Asked Questions)
===========================================

:Date: $Date$
:Revision: $Revision$
:Web site: http://docutils.sourceforge.net/
:Copyright: This document has been placed in the public domain.

.. Please note that until there's a Q&A-specific construct available,
   this FAQ will use section titles for questions.  Therefore
   questions must fit on one line.  The title may be a summary of the
   question, with the full question in the section body.


.. contents::
.. sectnum::


This is a work in progress.  Please feel free to ask questions and/or
provide answers; send email to the `Docutils-users`_ mailing list.
Project members should feel free to edit the source text file
directly.

.. _let us know:
.. _Docutils-users: docs/user/mailing-lists.html#docutils-users


Docutils
========

What is Docutils?
-----------------

Docutils_ is a system for processing plaintext documentation into
useful formats, such as HTML, XML, and LaTeX.  It supports multiple
types of input, such as standalone files (implemented), inline
documentation from Python modules and packages (under development),
`PEPs (Python Enhancement Proposals)`_ (implemented), and others as
discovered.

For an overview of the Docutils project implementation, see `PEP
258`_, "Docutils Design Specification".

Docutils is implemented in Python_.

.. _Docutils: http://docutils.sourceforge.net/
.. _PEPs (Python Enhancement Proposals):
   http://www.python.org/peps/pep-0012.html
.. _PEP 258: http://www.python.org/peps/pep-0258.html
.. _Python: http://www.python.org/


Why is it called "Docutils"?
----------------------------

Docutils is short for "Python Documentation Utilities".  The name
"Docutils" was inspired by "Distutils", the Python Distribution
Utilities architected by Greg Ward, a component of Python's standard
library.

The earliest known use of the term "docutils" in a Python context was
a `fleeting reference`__ in a message by Fred Drake on 1999-12-02 in
the Python Doc-SIG mailing list.  It was suggested `as a project
name`__ on 2000-11-27 on Doc-SIG, again by Fred Drake, in response to
a question from Tony "Tibs" Ibbs: "What do we want to *call* this
thing?".  This was shortly after David Goodger first `announced
reStructuredText`__ on Doc-SIG.

Tibs used the name "Docutils" for `his effort`__ "to document what the
Python docutils package should support, with a particular emphasis on
documentation strings".  Tibs joined the current project (and its
predecessors) and graciously donated the name.

For more history of reStructuredText and the Docutils project, see `An
Introduction to reStructuredText`_.

Please note that the name is "Docutils", not "DocUtils" or "Doc-Utils"
or any other variation.

.. _An Introduction to reStructuredText:
   http://docutils.sourceforge.net/docs/ref/rst/introduction.html
__ http://mail.python.org/pipermail/doc-sig/1999-December/000878.html
__ http://mail.python.org/pipermail/doc-sig/2000-November/001252.html
__ http://mail.python.org/pipermail/doc-sig/2000-November/001239.html
__ http://homepage.ntlworld.com/tibsnjoan/docutils/STpy.html


Is there a GUI authoring environment for Docutils?
--------------------------------------------------

DocFactory_ is under development.  It uses wxPython and looks very
promising.

.. _DocFactory:
   http://docutils.sf.net/sandbox/gschwant/docfactory/doc/


What is the status of the Docutils project?
-------------------------------------------

Although useful and relatively stable, Docutils is experimental code,
with APIs and architecture subject to change.

Our highest priority is to fix bugs as they are reported.  So the
latest code from the repository_ (or the snapshots_) is almost always
the most stable (bug-free) as well as the most featureful.


What is the Docutils project release policy?
--------------------------------------------

It's "release early & often".  We also have automatically-generated
snapshots_ which always contain the latest code from the repository_.
As the project matures, we may formalize on a
stable/development-branch scheme, but we're not using anything like
that yet.

.. _repository: docs/dev/repository.html
.. _snapshots: http://docutils.sourceforge.net/#download


reStructuredText
================

What is reStructuredText?
-------------------------

reStructuredText_ is an easy-to-read, what-you-see-is-what-you-get
plaintext markup syntax and parser system.  The reStructuredText
parser is a component of Docutils_.  reStructuredText is a revision
and reinterpretation of the StructuredText_ and Setext_ lightweight
markup systems.

If you are reading this on the web, you can see for yourself.  `The
source for this FAQ <FAQ.txt>`_ is written in reStructuredText; open
it in another window and compare them side by side.

`A ReStructuredText Primer`_ and the `Quick reStructuredText`_ user
reference are a good place to start.  The `reStructuredText Markup
Specification`_ is a detailed technical specification.

.. _A ReStructuredText Primer:
   http://docutils.sourceforge.net/docs/user/rst/quickstart.html
.. _Quick reStructuredText:
   http://docutils.sourceforge.net/docs/user/rst/quickref.html
.. _reStructuredText Markup Specification:
   http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
.. _StructuredText:
   http://dev.zope.org/Members/jim/StructuredTextWiki/FrontPage/
.. _Setext: http://docutils.sourceforge.net/mirror/setext.html


Why is it called "reStructuredText"?
------------------------------------

The name came from a combination of "StructuredText", one of
reStructuredText's predecessors, with "re": "revised", "reworked", and
"reinterpreted", and as in the ``re.py`` regular expression module.
For a detailed history of reStructuredText and the Docutils project,
see `An Introduction to reStructuredText`_.


What's the standard abbreviation for "reStructuredText"?
--------------------------------------------------------

"RST" and "ReST" (or "reST") are both acceptable.  Care should be
taken with capitalization, to avoid confusion with "REST__", an
acronym for "Representational State Transfer".

The abbreviations "reSTX" and "rSTX"/"rstx" should **not** be used;
they overemphasize reStructuredText's precedessor, Zope's
StructuredText.

__ http://en.wikipedia.org/wiki/Representational_State_Transfer


What's the standard filename extension for a reStructuredText file?
-------------------------------------------------------------------

It's ".txt".  Some people would like to use ".rest" or ".rst" or
".restx", but why bother?  ReStructuredText source files are meant to
be readable as plaintext, and most operating systems already associate
".txt" with text files.  Using a specialized filename extension would
require that users alter their OS settings, which is something that
many users will not be willing or able to do.


Are there any reStructuredText editor extensions?
-------------------------------------------------

See `Editor Support for reStructuredText`__.

__ http://docutils.sf.net/tools/editors/README.html


How can I indicate the document title?  Subtitle?
-------------------------------------------------

A uniquely-adorned section title at the beginning of a document is
treated specially, as the document title.  Similarly, a
uniquely-adorned section title immediately after the document title
becomes the document subtitle.  For example::

    This is the Document Title
    ==========================

    This is the Document Subtitle
    -----------------------------

    Here's an ordinary paragraph.

Counterexample::

    Here's an ordinary paragraph.

    This is *not* a Document Title
    ==============================

    The "ordinary paragraph" above the section title
    prevents it from becoming the document title.

Another counterexample::

    This is not the Document Title,  because...
    ===========================================

    Here's an ordinary paragraph.

    ... the title adornment is not unique
    =====================================

    Another ordinary paragraph.


How can I represent esoteric characters (e.g. character entities) in a document?
--------------------------------------------------------------------------------

For example, say you want an em-dash (XML character entity &mdash;,
Unicode character U+2014) in your document: use a real em-dash.
Insert concrete characters (e.g. type a *real* em-dash) into your
input file, using whatever encoding suits your application, and tell
Docutils the input encoding.  Docutils uses Unicode internally, so the
em-dash character is a real em-dash internally.

Emacs users should refer to the `Emacs Support for reStructuredText`__
document.  Tips for other editors are welcome.

__ http://docutils.sourceforge.net/tools/editors/emacs/README.html

ReStructuredText has no character entity subsystem; it doesn't know
anything about XML charents.  To Docutils, "&mdash;" in input text is
7 discrete characters; no interpretation happens.  When writing HTML,
the "&" is converted to "&amp;", so in the raw output you'd see
"&amp;mdash;".  There's no difference in interpretation for text
inside or outside inline literals or literal blocks -- there's no
character entity interpretation in either case.

If you can't use a Unicode-compatible encoding and must rely on 7-bit
ASCII, there is a workaround.  New in Docutils 0.3.10 is a set of
`Standard Substitution Definition Sets`_, which provide equivalents of
XML & HTML character entity sets as substitution definitions.  For
example, the Japanese yen currency symbol can be used as follows::

    .. include:: <xhtml1-lat1.txt>

    |yen| 600 for a complete meal?  That's cheap!

For earlier versions of Docutils, equivalent files containing
character entity set substitution definitions using the "unicode_"
directive `are available`_.  Please read the `description and
instructions`_ for use.  Thanks to David Priest for the original idea.

If you insist on using XML-style charents, you'll have to implement a
pre-processing system to convert to UTF-8 or something.  That
introduces complications though; you can no longer *write* about
charents naturally; instead of writing "&mdash;" you'd have to write
"&amp;mdash;".

For the common case of long dashes, you might also want to insert the
following substitution definitons into your document (both of them are
using the "unicode_" directive)::

    .. |--| unicode:: U+2013   .. en dash
    .. |---| unicode:: U+2014  .. em dash, trimming surrounding whitespace
       :trim:

.. |--| unicode:: U+2013   .. en dash
.. |---| unicode:: U+2014  .. em dash, trimming surrounding whitespace
   :trim:

Now you can write dashes using pure ASCII: "``foo |--| bar; foo |---|
bar``", rendered as "foo |--| bar; foo |---| bar".  (Note that Mozilla
and Firefox may render this incorrectly.)  The ``:trim:`` option for
the em dash is necessary because you cannot write "``foo|---|bar``";
thus you need to add spaces ("``foo |---| bar``") and advise the
reStructuredText parser to trim the spaces.

.. _Standard Substitution Definition Sets:
   http://docutils.sf.net/docs/ref/rst/substitutions.html
.. _unicode:
   http://docutils.sf.net/docs/ref/rst/directives.html#unicode-character-codes
.. _are available: http://docutils.sourceforge.net/tmp/charents/
.. _tarball: http://docutils.sourceforge.net/tmp/charents.tgz
.. _description and instructions:
   http://docutils.sourceforge.net/tmp/charents/README.html
.. _to-do list: http://docutils.sourceforge.net/docs/dev/todo.html


How can I generate backticks using a Scandinavian keyboard?
-----------------------------------------------------------

The use of backticks in reStructuredText is a bit awkward with
Scandinavian keyboards, where the backtick is a "dead" key.  To get
one ` character one must press SHIFT-` + SPACE.

Unfortunately, with all the variations out there, there's no way to
please everyone.  For Scandinavian programmers and technical writers,
this is not limited to reStructuredText but affects many languages and
environments.

Possible solutions include

* If you have to input a lot of backticks, simply type one in the
  normal/awkward way, select it, copy and then paste the rest (CTRL-V
  is a lot faster than SHIFT-` + SPACE).

* Use keyboard macros.

* Remap the keyboard.  The Scandinavian keyboard layout is awkward for
  other programming/technical characters too; for example, []{}
  etc. are a bit awkward compared to US keyboards.

  According to Axel Kollmorgen,

      Under Windows, you can use the `Microsoft Keyboard Layout Creator
      <http://www.microsoft.com/globaldev/tools/msklc.mspx>`__ to easily
      map the backtick key to a real backtick (no dead key). took me
      five minutes to load my default (german) keyboard layout, untick
      "Dead Key?" from the backtick key properties ("in all shift
      states"), "build dll and setup package", install the generated
      .msi, and add my custom keyboard layout via Control Panel >
      Regional and Language Options > Languages > Details > Add
      Keyboard layout (and setting it as default "when you start your
      computer").

* Use a virtual/screen keyboard or character palette, such as:

  - `Web-based keyboards <http://keyboard.lab.co.il/>`__ (IE only
    unfortunately).
  - Windows: `Click-N-Type <http://www.lakefolks.org/cnt/>`__.
  - Mac OS X: the Character Palette can store a set of favorite
    characters for easy input.  Open System Preferences,
    International, Input Menu tab, enable "Show input menu in menu
    bar", and be sure that Character Palette is enabled in the list.

If anyone knows of other/better solutions, please `let us know`_.


Are there any tools for HTML/XML-to-reStructuredText?  (Round-tripping)
-----------------------------------------------------------------------

People have tossed the idea around, and some implementations of
reStructuredText-generating tools can be found in the `Docutils Link
List`_.

There's no reason why reStructuredText should not be round-trippable
to/from XML; any technicalities which prevent round-tripping would be
considered bugs.  Whitespace would not be identical, but paragraphs
shouldn't suffer.  The tricky parts would be the smaller details, like
links and IDs and other bookkeeping.

For HTML, true round-tripping may not be possible.  Even adding lots
of extra "class" attributes may not be enough.  A "simple HTML" to RST
filter is possible -- for some definition of "simple HTML" -- but HTML
is used as dumb formatting so much that such a filter may not be
particularly useful.  An 80/20 approach should work though: build a
tool that does 80% of the work automatically, leaving the other 20%
for manual tweaks.

.. _Docutils Link List: docs/user/links.html


Are there any Wikis that use reStructuredText syntax?
-----------------------------------------------------

There are several, with various degrees of completeness.  With no
implied endorsement or recommendation, and in no particular order:

* `Webware for Python wiki
  <http://wiki.webwareforpython.org/thiswiki.html>`__
* `Ian Bicking's experimental code
  <http://docutils.sf.net/sandbox/ianb/wiki/Wiki.py>`__
* `MoinMoin <http://moinmoin.wikiwikiweb.de/>`__ has some support;
  `here's a sample <http://moinmoin.wikiwikiweb.de/RestSample>`__
* Zope-based `Zwiki <http://zwiki.org/>`__
* Zope3-based Zwiki (in the Zope 3 source tree as ``zope.products.zwiki``)
* `StikiWiki <http://mithrandr.moria.org/code/stikiwiki/>`__
* `Trac <http://projects.edgewall.com/trac/>`__ `supports using reStructuredText
  <http://projects.edgewall.com/trac/wiki/WikiRestructuredText>`__ as an
  alternative to wiki markup. This includes support for `TracLinks
  <http://projects.edgewall.com/trac/wiki/TracLinks>`__ from within RST
  text via a custom RST reference-directive or, even easier, an interpreted text
  role 'trac'
* `Vogontia <http://www.ososo.de/vogontia/>`__, a Wiki-like FAQ system

Please `let us know`_ of any other reStructuredText Wikis.

The example application for the `Web Framework Shootout
<http://colorstudy.com/docs/shootout.html>`__ article is a Wiki using
reStructuredText.


Are there any Weblog (Blog) projects that use reStructuredText syntax?
----------------------------------------------------------------------

With no implied endorsement or recommendation, and in no particular
order:

* `Firedrop <http://www.voidspace.org.uk/python/firedrop2/>`__
* `Python Desktop Server <http://pyds.muensterland.org/>`__
* `PyBloxsom <http://roughingit.subtlehints.net/pyblosxom/>`__
* `Lino WebMan <http://lino.sourceforge.net/webman.html>`__

Please `let us know`_ of any other reStructuredText Blogs.


Can lists be indented without generating block quotes?
------------------------------------------------------

Some people like to write lists with indentation, without intending a
block quote context, like this::

    paragraph

      * list item 1
      * list item 2

There has been a lot of discussion about this, but there are some
issues that would need to be resolved before it could be implemented.
There is a summary of the issues and pointers to the discussions in
`the to-do list`__.

__ http://docutils.sourceforge.net/docs/dev/todo.html#indented-lists


Could the requirement for blank lines around lists be relaxed?
--------------------------------------------------------------

Short answer: no.

In reStructuredText, it would be impossible to unambigously mark up
and parse lists without blank lines before and after.  Deeply nested
lists may look ugly with so many blank lines, but it's a price we pay
for unambiguous markup.  Some other plaintext markup systems do not
require blank lines in nested lists, but they have to compromise
somehow, either accepting ambiguity or requiring extra complexity.
For example, `Epytext <http://epydoc.sf.net/epytext.html#list>`__ does
not require blank lines around lists, but it does require that lists
be indented and that ambiguous cases be escaped.


How can I include mathematical equations in documents?
------------------------------------------------------

There is no elegant built-in way, yet.  There are several ideas, but
no obvious winner.  This issue requires a champion to solve the
technical and aesthetic issues and implement a generic solution.
Here's the `to-do list entry`__.

__ http://docutils.sourceforge.net/docs/dev/todo.html#math-markup

There are several quick & dirty ways to include equations in documents.
They all presently use LaTeX syntax or dialects of it.

* For LaTeX output, nothing beats raw LaTeX math.  A simple way is to
  use the `raw directive`_::

      .. raw:: latex

          \[ x^3 + 3x^2a + 3xa^2 + a^3, \]

  For inline math you could use substitutions of the raw directive but
  the recently added `raw role`_ is more convenient.  You must define a
  custom role based on it once in your document::

      .. role:: raw-latex(raw)
          :format: latex

  and then you can just use the new role in your text::

      the binomial expansion of :raw-latex:`$(x+a)^3$` is

  .. _raw directive: http://docutils.sourceforge.net/docs/ref/rst/
                     directives.html#raw-data-pass-through
  .. _raw role: http://docutils.sourceforge.net/docs/ref/rst/roles.html#raw

* Jens Jørgen Mortensen has implemented a "latex-math" role and
  directive, available from `his sandbox`__.

  __ http://docutils.sourceforge.net/sandbox/jensj/latex_math/

* For HTML the "Right" w3c-standard way to include math is MathML_.
  Unfortunately its rendering is still quite broken (or absent) on many
  browsers but it's getting better.  Another bad problem is that typing
  or reading raw MathML by humans is *really* painful, so embedding it
  in a reST document with the raw directive would defy the goals of
  readability and editability of reST (see an `example of raw MathML
  <http://sf.net/mailarchive/message.php?msg_id=2177102>`__).

  A much less painful way to generate HTML+MathML is to use itex2mml_ to
  convert a dialect of LaTeX syntax to presentation MathML.  Here is an
  example of potential `itex math markup
  <http://article.gmane.org/gmane.text.docutils.user/118>`__.  The
  simplest way to use it is to add ``html`` to the format lists for the
  raw directive/role and postprocess the resulting document with
  itex2mml.  This way you can *generate LaTeX and HTML+MathML from the
  same source*, but you must limit yourself to the intersection of LaTeX
  and itex markups for this to work.  Alan G. Isaac wrote a detailed
  HOWTO_ for this approach.

  .. _MathML: http://www.w3.org/Math/
  .. _itex2mml: http://pear.math.pitt.edu/mathzilla/itex2mml.html
  .. _HOWTO: http://www.american.edu/econ/itex2mml/mathhack.rst

* The other way to add math to HTML is to use images of the equations,
  typically generated by TeX.  This is inferior to MathML in the long
  term but is perhaps more accessible nowdays.

  Of course, doing it by hand is too much work.  Beni Cherniavsky has
  written some `preprocessing scripts`__ for converting the
  ``texmath`` role/directive into images for HTML output and raw
  directives/subsitution for LaTeX output.  This way you can *generate
  LaTeX and HTML+images from the same source*.  `Instructions here`__.

  __ http://docutils.sourceforge.net/sandbox/cben/rolehack/
  __ http://docutils.sourceforge.net/sandbox/cben/rolehack/README.html


Is nested inline markup possible?
---------------------------------

Not currently, no.  It's on the `to-do list`__ (`details here`__), and
hopefully will be part of the reStructuredText parser soon.  At that
time, markup like this will become possible::

    Here is some *emphasized text containing a `hyperlink`_ and
    ``inline literals``*.

__ http://docutils.sf.net/docs/dev/todo.html#nested-inline-markup
__ http://docutils.sf.net/docs/dev/rst/alternatives.html#nested-inline-markup

There are workarounds, but they are either convoluted or ugly or both.
They are not recommended.

* Inline markup can be combined with hyperlinks using `substitution
  definitions`__ and references__ with the `"replace" directive`__.
  For example::

      Here is an |emphasized hyperlink|_.

      .. |emphasized hyperlink| replace:: *emphasized hyperlink*
      .. _emphasized hyperlink: http://example.org

  It is not possible for just a portion of the replacement text to be
  a hyperlink; it's the entire replacement text or nothing.

  __ http://docutils.sf.net/docs/ref/rst/restructuredtext.html#substitution-definitions
  __ http://docutils.sf.net/docs/ref/rst/restructuredtext.html#substitution-references
  __ http://docutils.sf.net/docs/ref/rst/directives.html#replace

* The `"raw" directive`__ can be used to insert raw HTML into HTML
  output::

      Here is some |stuff|.

      .. |stuff| raw:: html

         <em>emphasized text containing a
         <a href="http://example.org">hyperlink</a> and
         <tt>inline literals</tt></em>

  Raw LaTeX is supported for LaTeX output, etc.

  __ http://docutils.sf.net/docs/ref/rst/directives.html#raw


How to indicate a line break or a significant newline?
------------------------------------------------------

`Line blocks`__ are designed for address blocks, verse, and other
cases where line breaks are significant and must be preserved.  Unlike
literal blocks, the typeface is not changed, and inline markup is
recognized.  For example::

    | A one, two, a one two three four
    |
    | Half a bee, philosophically,
    |     must, *ipso facto*, half not be.
    | But half the bee has got to be,
    |     *vis a vis* its entity.  D'you see?
    |
    | But can a bee be said to be
    |     or not to be an entire bee,
    |         when half the bee is not a bee,
    |             due to some ancient injury?
    |
    | Singing...

__ http://docutils.sf.net/docs/ref/rst/restructuredtext.html#line-blocks

Here's a workaround for manually inserting explicit line breaks in
HTML output::

    .. |br| raw:: html

       <br />

    I want to break this line here: |br| this is after the break.

    If the extra whitespace bothers you, |br|\ backslash-escape it.


A URL containing asterisks doesn't work.  What to do?
-----------------------------------------------------

Asterisks are valid URL characters (see :RFC:`2396`), sometimes used
in URLs.  For example::

    http://cvs.example.org/viewcvs.py/*checkout*/module/file

Unfortunately, the parser thinks the asterisks are indicating
emphasis.  The slashes serve as delineating punctuation, allowing the
asterisks to be recognized as markup.  The example above is separated
by the parser into a truncated URL, an emphasized word, and some
regular text::

    http://cvs.example.org/viewcvs.py/
    *checkout*
    /module/file

To turn off markup recognition, use a backslash to escape at least the
first asterisk, like this::

    http://cvs.example.org/viewcvs.py/\*checkout*/module/file

Escaping the second asterisk doesn't hurt, but it isn't necessary.


How can I make a literal block with *some* formatting?
------------------------------------------------------

Use the `parsed-literal`_ directive.

.. _parsed-literal: docs/ref/rst/directives.html#parsed-literal

Scenario: a document contains some source code, which calls for a
literal block to preserve linebreaks and whitespace.  But part of the
source code should be formatted, for example as emphasis or as a
hyperlink.  This calls for a *parsed* literal block::

    .. parsed-literal::

       print "Hello world!"  # *tricky* code [1]_

The emphasis (``*tricky*``) and footnote reference (``[1]_``) will be
parsed.


Can reStructuredText be used for web or generic templating?
-----------------------------------------------------------

Docutils and reStructuredText can be used with or as a component of a
templating system, but they do not themselves include templating
functionality.  Templating should simply be left to dedicated
templating systems.  Users can choose a templating system to apply to
their reStructuredText documents as best serves their interests.

There are many good templating systems for Python (ht2html_, YAPTU_,
Quixote_'s PTL, Cheetah_, etc.; see this non-exhaustive list of `some
other templating systems`_), and many more for other languages, each
with different approaches.  We invite you to try several and find one
you like.  If you adapt it to use Docutils/reStructuredText, please
consider contributing the code to Docutils or `let us know`_ and we'll
keep a list here.

One reST-specific web templating system is `rest2web
<http://www.voidspace.org.uk/python/rest2web>`_, a tool for
automatically building websites, or parts of websites.

.. _ht2html: http://ht2html.sourceforge.net/
.. _YAPTU:
   http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52305
.. _Quixote: http://www.mems-exchange.org/software/quixote/
.. _Cheetah: http://www.cheetahtemplate.org/
.. _some other templating systems:
   http://webware.sourceforge.net/Papers/Templates/


HTML Writer
===========

What is the status of the HTML Writer?
--------------------------------------

The HTML Writer module, ``docutils/writers/html4css1.py``, is a
proof-of-concept reference implementation.  While it is a complete
implementation, some aspects of the HTML it produces may be
incompatible with older browsers or specialized applications (such as
web templating).  Alternate implementations are welcome.


What kind of HTML does it produce?
----------------------------------

It produces XHTML compatible with the `XHTML 1.0`_ specification.  A
cascading stylesheet is required for proper viewing with a modern
graphical browser.  Correct rendering of the HTML produced depends on
the CSS support of the browser.  A general-purpose stylesheet,
``html4css1.css`` is provided with the code, and is embedded by
default.  It is installed in the "writers/support/" subdirectory
within the Docutils package.  Use the ``--help`` command-line option
to see the specific location on your machine.

.. _XHTML 1.0: http://www.w3.org/TR/xhtml1/


What browsers are supported?
----------------------------

No specific browser is targeted; all modern graphical browsers should
work.  Some older browsers, text-only browsers, and browsers without
full CSS support are known to produce inferior results.  Firefox,
Safari, Mozilla (version 1.0 and up), and MS Internet Explorer
(version 5.0 and up) are known to give good results.  Reports of
experiences with other browsers are welcome.


Unexpected results from tools/rst2html.py: H1, H1 instead of H1, H2.  Why?
--------------------------------------------------------------------------

Here's the question in full:

    I have this text::

        Heading 1
        =========

        All my life, I wanted to be H1.

        Heading 1.1
        -----------

        But along came H1, and so shouldn't I be H2?
        No!  I'm H1!

        Heading 1.1.1
        *************

        Yeah, imagine me, I'm stuck at H3!  No?!?

    When I run it through tools/rst2html.py, I get unexpected results
    (below).  I was expecting H1, H2, then H3; instead, I get H1, H1,
    H2::

        ...
        <html lang="en">
        <head>
        ...
        <title>Heading 1</title>
        </head>
        <body>
        <div class="document" id="heading-1">
        <h1 class="title">Heading 1</h1>                <-- first H1
        <p>All my life, I wanted to be H1.</p>
        <div class="section" id="heading-1-1">
        <h1><a name="heading-1-1">Heading 1.1</a></h1>        <-- H1
        <p>But along came H1, and so now I must be H2.</p>
        <div class="section" id="heading-1-1-1">
        <h2><a name="heading-1-1-1">Heading 1.1.1</a></h2>
        <p>Yeah, imagine me, I'm stuck at H3!</p>
        ...

    What gives?

Check the "class" attribute on the H1 tags, and you will see a
difference.  The first H1 is actually ``<h1 class="title">``; this is
the document title, and the default stylesheet renders it centered.
There can also be an ``<h2 class="subtitle">`` for the document
subtitle.

If there's only one highest-level section title at the beginning of a
document, it is treated specially, as the document title.  (Similarly, a
lone second-highest-level section title may become the document
subtitle.)  See `How can I indicate the document title?  Subtitle?`_ for
details.  Rather than use a plain H1 for the document title, we use ``<h1
class="title">`` so that we can use H1 again within the document.  Why
do we do this?  HTML only has H1-H6, so by making H1 do double duty, we
effectively reserve these tags to provide 6 levels of heading beyond the
single document title.

HTML is being used for dumb formatting for nothing but final display.
A stylesheet *is required*, and one is provided; see `What kind of
HTML does it produce?`_ above.  Of course, you're welcome to roll your
own.  The default stylesheet provides rules to format ``<h1
class="title">`` and ``<h2 class="subtitle">`` differently from
ordinary ``<h1>`` and ``<h2>``::

    h1.title {
      text-align: center }

    h2.subtitle {
      text-align: center }

If you don't want the top section heading to be interpreted as a
title at all, disable the `doctitle_xform`_ setting
(``--no-doc-title`` option).  This will interpret your document
differently from the standard settings, which might not be a good
idea.  If you don't like the reuse of the H1 in the HTML output, you
can tweak the `initial_header_level`_ setting
(``--initial-header-level`` option) -- but unless you match its value
to your specific document, you might end up with bad HTML (e.g. H3
without H2).

.. _doctitle_xform:
   http://docutils.sourceforge.net/docs/user/config.html#doctitle-xform
.. _initial_header_level:
   http://docutils.sourceforge.net/docs/user/config.html#initial-header-level

(Thanks to Mark McEahern for the question and much of the answer.)


Why do enumerated lists only use numbers (no letters or roman numerals)?
------------------------------------------------------------------------

The rendering of enumerators (the numbers or letters acting as list
markers) is completely governed by the stylesheet, so either the
browser can't find the stylesheet (try using the "--embed-stylesheet"
option), or the browser can't understand it (try a recent Firefox,
Mozilla, Konqueror, Opera, Safari, or even MSIE).


There appear to be garbage characters in the HTML.  What's up?
--------------------------------------------------------------

What you're seeing is most probably not garbage, but the result of a
mismatch between the actual encoding of the HTML output and the
encoding your browser is expecting.  Your browser is misinterpreting
the HTML data, which is encoded text.  A discussion of text encodings
is beyond the scope of this FAQ; see one or more of these documents
for more info:

* `UTF-8 and Unicode FAQ for Unix/Linux
  <http://www.cl.cam.ac.uk/~mgk25/unicode.html>`_

* Chapters 3 and 4 of `Introduction to i18n [Internationalization]
  <http://www.debian.org/doc/manuals/intro-i18n/>`_

* `Python Unicode Tutorial
  <http://www.reportlab.com/i18n/python_unicode_tutorial.html>`_

* `Python Unicode Objects: Some Observations on Working With Non-ASCII
  Character Sets <http://effbot.org/zone/unicode-objects.htm>`_

The common case is with the default output encoding (UTF-8), when
either numbered sections are used (via the "sectnum_" directive) or
symbol-footnotes.  3 non-breaking spaces are inserted in each numbered
section title, between the generated number and the title text.  Most
footnote symbols are not available in ASCII, nor are non-breaking
spaces.  When encoded with UTF-8 and viewed with ordinary ASCII tools,
these characters will appear to be multi-character garbage.

You may have an decoding problem in your browser (or editor, etc.).
The encoding of the output is set to "utf-8", but your browswer isn't
recognizing that.  You can either try to fix your browser (enable
"UTF-8 character set", sometimes called "Unicode"), or choose a
different encoding for the HTML output.  You can also try
``--output-encoding=ascii:xmlcharrefreplace`` for HTML (not applicable
to non-XMLish outputs).

If you're generating document fragments, the "Content-Type" metadata
(between the HTML ``<head>`` and ``</head>`` tags) must agree with the
encoding of the rest of the document.  For UTF-8, it should be::

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

Also, Docutils normally generates an XML declaration as the first line
of the output.  It must also match the document encoding.  For UTF-8::

    <?xml version="1.0" encoding="utf-8" ?>

.. _sectnum:
   http://docutils.sourceforge.net/docs/ref/rst/directives.html#sectnum


How can I retrieve the body of the HTML document?
-------------------------------------------------

(This is usually needed when using Docutils in conjunction with a
templating system.)

You can use the `docutils.core.publish_parts()`_ function, which
returns a dictionary containing an 'html_body_' entry.

.. _docutils.core.publish_parts():
   docs/api/publisher.html#publish-parts
.. _html_body:
   docs/api/publisher.html#html-body


Why is the Docutils XHTML served as "Content-type: text/html"?
--------------------------------------------------------------

Full question:

    Docutils' HTML output looks like XHTML and is advertised as such::

      <?xml version="1.0" encoding="utf-8" ?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
       "http://www.w3.org/TR/xht ml1/DTD/xhtml1-transitional.dtd">

    But this is followed by::

      <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    Shouldn't this be "application/xhtml+xml" instead of "text/html"?

In a perfect web, the Docutils XHTML output would be 100% strict
XHTML.  But it's not a perfect web, and a major source of imperfection
is Internet Explorer.  Despite it's drawbacks, IE still represents the
majority of web browsers, and cannot be ignored.

Short answer: if we didn't serve XHTML as "text/html" (which is a
perfectly valid thing to do), it couldn't be viewed in Internet
Explorer.  

Long answer: see the `"Criticisms of Internet Explorer" Wikipedia
entry <http://en.wikipedia.org/wiki/Criticisms_of_Internet_Explorer#XHTML>`__.

However, there's also `Sending XHTML as text/html Considered
Harmful`__.  What to do, what to do?  We're damned no matter what we
do.  So we'll continue to do the practical instead of the pure:
support the browsers that are actually out there, and not fight for
strict standards compliance.

__ http://hixie.ch/advocacy/xhtml

(Thanks to Martin F. Krafft, Robert Kern, Michael Foord, and Alan
G. Isaac.)


Python Source Reader
====================

Can I use Docutils for Python auto-documentation?
-------------------------------------------------

Yes, in conjunction with other projects.

Docstring extraction functionality from within Docutils is still under
development.  There is most of a source code parsing module in
docutils/readers/python/moduleparser.py.  We do plan to finish it
eventually.  Ian Bicking wrote an initial front end for the
moduleparser.py module, in sandbox/ianb/extractor/extractor.py.  Ian
also did some work on the Python Source Reader
(docutils.readers.python) component at PyCon DC 2004.

Version 2.0 of Ed Loper's `Epydoc <http://epydoc.sourceforge.net/>`_
supports reStructuredText-format docstrings for HTML output.  Docutils
0.3 or newer is required.  Development of a Docutils-specific
auto-documentation tool will continue.  Epydoc works by importing
Python modules to be documented, whereas the Docutils-specific tool,
described above, will parse modules without importing them (as with
`HappyDoc <http://happydoc.sourceforge.net/>`_, which doesn't support
reStructuredText).

The advantages of parsing over importing are security and flexibility;
the disadvantage is complexity/difficulty.

* Security: untrusted code that shouldn't be executed can be parsed;
  importing a module executes its top-level code.
* Flexibility: comments and unofficial docstrings (those not supported
  by Python syntax) can only be processed by parsing.
* Complexity/difficulty: it's a lot harder to parse and analyze a
  module than it is to ``import`` and analyze one.

For more details, please see "Docstring Extraction Rules" in `PEP
258`_, item 3 ("How").


Miscellaneous
=============

Is the Docutils document model based on any existing XML models?
----------------------------------------------------------------

Not directly, no.  It borrows bits from DocBook, HTML, and others.  I
(David Goodger) have designed several document models over the years,
and have my own biases.  The Docutils document model is designed for
simplicity and extensibility, and has been influenced by the needs of
the reStructuredText markup.