lua-resty-hoedown

lua-resty-hoedown is a Markdown, SmartyPants, buffer, and html and href/url escaping library implementing LuaJIT bindings to Hoedown.

Hello World with lua-resty-hoedown

local hoedown = require "resty.hoedown"
hoedown[[
# Are you ready for the truth?

Now that there is the Tec-9, a crappy spray gun from South Miami.
This gun is advertised as the most popular gun in American crime.
Do you believe that shit? It actually says that in the little book
that comes with it: the most popular gun in American crime. Like
they're actually proud of that shit.

## I'm serious as a heart attack

The path of the righteous man is beset on all sides by the iniquities
of the selfish and the tyranny of evil men. Blessed is he who, in the
name of charity and good will, shepherds the weak through the valley
of darkness, for he is truly his brother's keeper and the finder of
lost children. And I will strike down upon thee with great vengeance
and furious anger those who would attempt to poison and destroy My
brothers.
]]

This will return string containing:

<h1>Are you ready for the truth?</h1>

<p>Now that there is the Tec-9, a crappy spray gun from South Miami.
This gun is advertised as the most popular gun in American crime.
Do you believe that shit? It actually says that in the little book
that comes with it: the most popular gun in American crime. Like
they&#39;re actually proud of that shit.</p>

<h2>I&#39;m serious as a heart attack</h2>

<p>The path of the righteous man is beset on all sides by the iniquities
of the selfish and the tyranny of evil men. Blessed is he who, in the
name of charity and good will, shepherds the weak through the valley
of darkness, for he is truly his brother&#39;s keeper and the finder of
lost children. And I will strike down upon thee with great vengeance
and furious anger those who would attempt to poison and destroy My
brothers.</p>

Installation

Just place resty directory somewhere in your package.path. If you are using OpenResty, the default location would be /usr/local/openresty/lualib. Please check though that you do not overwrite the existing resty-directory if one exists already.

Compiling and Installing Hoedown C-library

These are just rudimentary notes. Better installation instructions will follow:

1. First download Hoedown from here: https://github.com/hoedown/hoedown
2. Run make
3. Place libhoedown.so somewhere in the default search path for dynamic libraries of your operating system (or modify resty/hoedown/library.lua and point ffi_load("libhoedown") with full path to libhoedown.so.

Using LuaRocks or MoonRocks

If you are using LuaRocks >= 2.2:

$ luarocks install lua-resty-hoedown

If you are using LuaRocks < 2.2:

$ luarocks install --server=http://rocks.moonscript.org moonrocks
$ moonrocks install lua-resty-hoedown

MoonRocks repository for lua-resty-hoedown is located here: https://rocks.moonscript.org/modules/bungle/lua-resty-hoedown.

Lua API

There are some functions called free on the API (to be complete implementation of Hoedown). You don't really need to call :free() as the library automatically handles freeing the external resources using normal LuaJIT garbage collector (the library registers the garbage collector handlers with ffi.gc).

Document Processing Extensions

With extensions, you may extend how to document processing works. Here are the available extensions:

tables                = HOEDOWN_EXT_TABLES,
fenced_code           = HOEDOWN_EXT_FENCED_CODE,
footnotes             = HOEDOWN_EXT_FOOTNOTES,
autolink              = HOEDOWN_EXT_AUTOLINK,
strikethrough         = HOEDOWN_EXT_STRIKETHROUGH,
underline             = HOEDOWN_EXT_UNDERLINE,
highlight             = HOEDOWN_EXT_HIGHLIGHT,
quote                 = HOEDOWN_EXT_QUOTE,
superscript           = HOEDOWN_EXT_SUPERSCRIPT,
math                  = HOEDOWN_EXT_MATH,
no_intra_emphasis     = HOEDOWN_EXT_NO_INTRA_EMPHASIS,
space_headers         = HOEDOWN_EXT_SPACE_HEADERS,
math_explicit         = HOEDOWN_EXT_MATH_EXPLICIT,
disable_indented_code = HOEDOWN_EXT_DISABLE_INDENTED_CODE

Example

local hoedown = require "resty.hoedown"
print(hoedown.document.extensions.tables)
local doc = require "resty.hoedown.document"
local extensions = doc.extensions
print(extensions.tables)

HTML Rendering Flags

With HTML rendering flags you can control the HTML rendering process. Hare are the available flags:

skip_html = HOEDOWN_HTML_SKIP_HTML,
escape    = HOEDOWN_HTML_ESCAPE,
hard_wrap = HOEDOWN_HTML_HARD_WRAP,
use_xhtml = HOEDOWN_HTML_USE_XHTML

Example

local hoedown = require "resty.hoedown"
print(hoedown.html.flags.skip_html)
local html  = require "resty.hoedown.html"
local flags = html.flags
print(flags.use_xhtml)

HTML Tag States

These present values returned from resty.hoedown.html.is_tag function. The possible values are:

none  = HOEDOWN_HTML_TAG_NONE,
open  = HOEDOWN_HTML_TAG_OPEN,
close = HOEDOWN_HTML_TAG_CLOSE

Example

local hoedown = require "resty.hoedown"
print(hoedown.html.tag.open)
local html = require "resty.hoedown.html"
local tag  = html.tag
print(tag.open)

resty.hoedown

A helper library that you may require with a single statement.

string hoedown(source, opts)

Helper function to rendering. source is a string containing a source document. You can also pass in options with opts argument. Here are the different options that you may use (you can also skip passing options):

opts = {
    renderer    = ("html" or "html.toc" or function or nil),
    extensions  = (table or number or nil),
    max_nesting = (number or nil),
    flags       = (table or number or nil),
    nesting     = (number or nil),
    smartypants = (true or false or nil)
}

Example

local hoedown = require "resty.hoedown"
print(hoedown[[
# Hello World

Hi this is Markdown.
]])

local flags = hoedown.html.flags

print(hoedown([[
# Hello World

Hi this is Markdown.
]], {
    rendered    = "html.toc",
    nesting     = 1,
    flags       = { flags.use_xhtml, "escape", 1 },
    extensions  = { "underline", "quote" },
    smartypants = true
}))

Fields

table resty.hoedown.buffer

This returns a buffer module.

table resty.hoedown.document

This returns a document module.

table resty.hoedown.html

This returns an html module.

table resty.hoedown.escape

This returns an escape module.

table resty.hoedown.version

This returns a version module.

resty.hoedown.buffer

cdata buffer.context

string buffer.data

number buffer.size

number buffer.asize

number buffer.unit

table buffer.new(size)

buffer:reset()

buffer:grow(size)

buffer:put(str)

buffer:puts(str)

buffer:set(str)

buffer:sets(str)

boolean buffer:eq(str)

boolean buffer:eqs(str)

number buffer:prefix(prefix)

buffer:slurp(size)

cdata buffer:cstr()

buffer:printf(format, ...)

buffer:free()

number buffer.__len()

boolean buffer:__eq()

string buffer:__concat(x, y)

string buffer:__tostring()

resty.hoedown.document

cdata document.context

table document.extensions

table document.new(renderer, extensions, max_nesting)

string document:render(data)

string document:render_inline(date)

document:free()

resty.hoedown.html

cdata html.context

table html.flags

table html.tag

string html.smartypants(data)

number html.is_tag(data, tag)

table html.new(flags, nesting)

html:free()

table html.toc

table html.toc.new(nesting)

html.toc:free()

resty.hoedown.escape

string escape(source, secure)

string escape.href(source)

string escape.html(source, secure)

resty.hoedown.version

number version.major

number version.minor

number version.revision

string version:__tostring()

License

lua-resty-hoedown uses two clause BSD license.

Copyright (c) 2014, Aapo Talvensaari
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice, this
  list of conditions and the following disclaimer in the documentation and/or
  other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.