# Using the Lore Documentation System

## Writing Lore Documents

### Overview

Lore documents are a special subset of XHTML documents. They use specific subset of XHTML, together with custom classes, to allow a wide variety of document elements, including some Python-specific ones. Lore documents, in particular, are well-formed XML documents. XML can be written using a wide variety of tools: from run of the mill editors such as vi, through editors with XML help like EMACS and ending with XML specific tools like (need name of XML editor here). Here, we will not cover the specifics of writing XML documents, except for a very broad overview.

XML documents contain elements, which are delimited by an opening tag which looks like `<tag-name attribute="value">` and ends with a closing tag, which looks like `</tag-name>`. If an elements happen to contain nothing, it can be shortened to `<tag-name />`. Elements can contain other elements, or text. Text can contain any characters except <, > and &. These characters are rendered by &lt;, &gt; and &amp;, respectively.

A Lore document is a single `html` element. Inside this element, there are exactly two top-level elements: `head` and `body`. The `head` element must contain exactly one element: `title`, containing the title of the document. Most of the document will be contained in the `body` element. The `body` element must start with an `h1` (top-level header) element, which contains the exact same content as the `title` element.

Thus, a fairly minimal Lore document might look like:

    <html>
    <head><title>Title</title></head>
    <body><h1>Title</h1></body>
    </html>

### Elements and Their Uses

`p`: The paragraph element. Most of the document should be inside paragraphs.

`span`: The span element is an element which has no meaning -- unless it has a special `class` attributes. The following classes have the stated meanings:

`footnote`
  a small comment which should not be inside the main text-flow.
`manhole-output`
  This signifies, within a manhole transcript, that the enclosed text is the output and not something the user has to input.
`span`
  This should be an empty element, with an attribute `value`. That attribute should be an index term, in the format of `generic!specific!more specific`. Usually, you will only have one level, in which case `value="term"` works.

`div`: The div element is equivalent to a span, except it always appears outside paragraphs. The following classes have the given meanings:

`note`
  A short note which is not necessary for the understanding of the text.
`doit`
  An indication that the discussed feature is not complete or implemented yet.
`boxed`
  An indication that the text should be clearly separated from its surroundings.

`a`: This element can have several meanings, depending on the attributes:

`name` attribute
  Add a label to the current position, which might be used in this document or other documents to refer to.
`href=URL`
  Refer to some WWW resource.
`href=relative-path`, `href=relative-path#label` or `href=#label`
  Refer to a position in a Lore resource. By default, relative links to `.html` files are changed to point to a `.xhtml` file. If you need a link to a local non-Lore .html file, use `class=absolute` to make Lore treat it as an absolute link.
`href=relative-path` with `class=py-listing` or `class=html-listing`
  Indicate the given resource is a part of the text flow, and should be inlined (and if possible, syntax highlighted).

`ol`, `ul`: A list. It can be enumerated or bulleted. Inside a list, the element `li` (for a list element) is valid.

`h2`, `h3`: Second- and third-level section headings.

`code`: a string which has meaning to the computer. There are many possible classes:

`API`
  A class, function or a module. It does not have to be a fully qualified name -- but if it isn't, a `base` attribute is necessary. Example: `<code class="API" base="urllib">urlencode<code>`.
`shell`
  Shell (usually Bourne) code.
`python`
  Python code
`py-prototype`
  Function prototype
`py-filename`
  Python file
`py-src-string`
  Python string
`py-signature`
  Function signature
`py-src-parameter`
  Parameter
`py-src-identifier`
  Identifier
`py-src-keyword`
  Keyword

`pre`: Preformatted text, usually for file listings. It can be used with the `python` class to indicate Python syntax coloring. Other possible classes are `shell` (to indicate a shell-transcript) or `python-interpreter` (to indicate an interactive interpreter transcript).

`img`: Insert the image indicated by the `src` attribute.

`q`: The quote signs (`"`) are not recommended except in preformatted or code environment. Instead, quote by using the `q` element which allows nested quotes and properly distinguishes opening quote from closing quote.

`em`, `strong`: Emphasise (or strongly emphasise) text.

`table`: Tabular data. Inside a table, use the `tr` element for each rows, and inside it use either `td` for a regular table cell or `th` for a table header (column or row).

`blockquote`: A long quote which should be properly seperated from the main text.

`cite`: Cite a resource.

`sub`, `sup`: subscripts and superscripts.

`link`: currently, the only `link` elements supported are for for indicating authorship. `<link rel="author" href="author-address@examples.com" title="Author Name" />` should be used to indicate authorship. Multiple instances are allowed, and indicate shared authorship.

## Writing Lore XHTML Templates

One of Lore's output formats is XHTML. Lore itself is very markup-light, but the output XHTML is much more markup intensive. Part of the auto-generated markup is directed by a special template.

The output of Lore is inserted into template in the following way:

- The title is appended into each element with class `title`.
- The body is inserted into the first element that has class `body`.
- The table of contents is inserted into the first element that has class `toc`.

In particular, most of the header is not tampered with -- so it is easy to indicate a CSS stylesheet in the template.

## Using Lore to Generate HTML

After having written a template, the easiest way to build HTML from the Lore document is by:

    % lore --config template=mytemplate.tpl mydocument.html

This will create a file called `mydocument.xhtml`.

For example, to generate the HTML version of the Twisted docs from a CVS checkout, do:See also the `admin/process-docs` script.

    % lore --config template=doc/howto/template.tpl doc/howto/*.html

## Using Lore to Generate LaTex

### Articles

    % lore --output latex mydocument.html

### Books

Have a Lore file for each section. Then, have a LaTeX file which inputs all the given LaTeX files. Generate all the LaTeX files by using

    % lore --output latex --config section *.html

in the relevant directory.

## Using Lore to Generate Slides

Lore can also be used to generate slides for presentations. The start of a new slide is indicated by use of an h2 tag, with the content between the opening and closing tags the title of the slide. Slides are generated by

    % lore --input lore-slides myslides.html

This, by default, will produce HTML output with one HTML file for each slide. For our example, the files would be named myslides-<number>.xhtml, where number is the slide number, starting with 0 for the title slide. Lore will look for a template file, either indicated by the `--config template=mytemplate.tpl` or the default template.tpl in the current directory. An example slide template is found in `doc/examples/slides-template.tpl`

The slides module currently supports three major output types: HTML, Magic Point, and LaTeX. The options for the latter two will be covered individually.

### Magic Point Output

Lore supports outputting to the Magic Point file format. Magicpoint is a presentation program for X, which can be installed on Debian by `apt-get install mgp` or by visiting the Magic Point homepage otherwise. A template file is required, `template.mgp` is shipped in the `twisted/lore` directory. Magic Point slides are generated by

    % lore --input lore-slides --output mgp \
      --config template=~/Twisted/twisted/lore/template.mgp \
      myslides.html

That will produce `myslides.mgp`.

### LaTeX Output

Lore can also produce slides in LaTeX format. It supports three main styles: one slide per page, two per page, and Prosper format, with the `--config` parameters being `page`, `twopage`, and `prosper` respectively. Prosper is a LaTeX class for creating slides, which can be installed on Debian by `apt-get install prosper` or by visiting the Prosper homepage. LaTeX format slides (using the Prosper option, for example) are generated by

    % lore --input lore-slides --output latex \
      --config prosper myslides.html

This will generate `myslides.tex` file that can be processed with `latex` or `pdftex` or the appropriate LaTeX processing command.

## Linting

    % lore --output lint mydocument.html

This will generate compiler-style (file:line:column:message) warnings. It is possible to integrate these warnings into a smart editor such as EMACS, but it has not been done yet.