require 'cgi'
require 'uri'
# :main: Creole
# The Creole parses and translates Creole formatted text into
# XHTML. Creole is a lightweight markup syntax similar to what many
# WikiWikiWebs use. Example syntax:
#
# = Heading 1 =
# == Heading 2 ==
# === Heading 3 ===
# **Bold text**
# //Italic text//
# [[Links]]
# |=Table|=Heading|
# |Table |Cells |
# {{image.png}}
#
# The simplest interface is Creole.creolize. The default handling of
# links allow explicit local links using the [[link]] syntax. External
# links will only be allowed if specified using http(s) and ftp(s)
# schemes. If special link handling is needed, such as inter-wiki or
# hierachical local links, you must inherit Creole::CreoleParser and
# override make_local_link.
#
# You can customize the created image markup by overriding
# make_image.
# Main Creole parser class. Call CreoleParser#parse to parse Creole
# formatted text.
#
# This class is not reentrant. A separate instance is needed for
# each thread that needs to convert Creole to HTML.
#
# Inherit this to provide custom handling of links. The overrideable
# methods are: make_local_link
module Creole
class Parser
# Allowed url schemes
# Examples: http https ftp ftps
attr_accessor :allowed_schemes
# Non-standard wiki text extensions enabled?
# E.g. underlined, deleted text etc
attr_writer :extensions
def extensions?; @extensions; end
# Disable url escaping for local links
# Escaping: [[/Test]] --> %2FTest
# No escaping: [[/Test]] --> Test
attr_writer :no_escape
def no_escape?; @no_escape; end
# Create a new CreoleParser instance.
def initialize(text, options = {})
@allowed_schemes = %w(http https ftp ftps)
@text = text
@extensions = @no_escape = nil
options.each_pair {|k,v| send("#{k}=", v) }
end
# Convert CCreole text to HTML and return
# the result. The resulting HTML does not contain and
# tags.
#
# Example:
#
# parser = CreoleParser.new("**Hello //World//**", :extensions => true)
# parser.to_html
# #=> "Hello World
"
def to_html
@out = ''
@p = false
@stack = []
parse_block(@text)
@out
end
protected
# Escape any characters with special meaning in HTML using HTML
# entities.
def escape_html(string)
CGI::escapeHTML(string)
end
# Escape any characters with special meaning in URLs using URL
# encoding.
def escape_url(string)
CGI::escape(string)
end
def start_tag(tag)
@stack.push(tag)
@out << '<' << tag << '>'
end
def end_tag
@out << ''
end
def toggle_tag(tag, match)
if @stack.include?(tag)
if @stack.last == tag
end_tag
else
@out << escape_html(match)
end
else
start_tag(tag)
end
end
def end_paragraph
end_tag while !@stack.empty?
@p = false
end
def start_paragraph
if @p
@out << ' ' if @out[-1] != ?\s
else
end_paragraph
start_tag('p')
@p = true
end
end
# Translate an explicit local link to a desired URL that is
# properly URL-escaped. The default behaviour is to convert local
# links directly, escaping any characters that have special
# meaning in URLs. Relative URLs in local links are not handled.
#
# Examples:
#
# make_local_link("LocalLink") #=> "LocalLink"
# make_local_link("/Foo/Bar") #=> "%2FFoo%2FBar"
#
# Must ensure that the result is properly URL-escaped. The caller
# will handle HTML escaping as necessary. HTML links will not be
# inserted if the function returns nil.
#
# Example custom behaviour:
#
# make_local_link("LocalLink") #=> "/LocalLink"
# make_local_link("Wikipedia:Bread") #=> "http://en.wikipedia.org/wiki/Bread"
def make_local_link(link) #:doc:
no_escape? ? link : escape_url(link)
end
# Sanatize a direct url (e.g. http://wikipedia.org/). The default
# behaviour returns the original link as-is.
#
# Must ensure that the result is properly URL-escaped. The caller
# will handle HTML escaping as necessary. Links will not be
# converted to HTML links if the function returns link.
#
# Custom versions of this function in inherited classes can
# implement specific link handling behaviour, such as redirection
# to intermediate pages (for example, for notifing the user that
# he is leaving the site).
def make_direct_link(url) #:doc:
url
end
# Sanatize and prefix image URLs. When images are encountered in
# Creole text, this function is called to obtain the actual URL of
# the image. The default behaviour is to return the image link
# as-is. No image tags are inserted if the function returns nil.
#
# Custom version of the method can be used to sanatize URLs
# (e.g. remove query-parts), inhibit off-site images, or add a
# base URL, for example:
#
# def make_image_link(url)
# URI.join("http://mywiki.org/images/", url)
# end
def make_image_link(url) #:doc:
url
end
# Create image markup. This
# method can be overridden to generate custom
# markup, for example to add html additional attributes or
# to put divs around the imgs.
def make_image(uri, alt)
if alt
' << ')
'
else
''
end
end
def make_headline(level, text)
"" << escape_html(text) << ""
end
def make_explicit_link(link)
begin
uri = URI.parse(link)
return uri.to_s if uri.scheme && @allowed_schemes.include?(uri.scheme)
rescue URI::InvalidURIError
end
make_local_link(link)
end
def parse_inline(str)
until str.empty?
case str
when /\A(\~)?((https?|ftps?):\/\/\S+?)(?=([\,.?!:;"'\)]+)?(\s|$))/
str = $'
if $1
@out << escape_html($2)
else
if uri = make_direct_link($2)
@out << '' << escape_html($2) << ''
else
@out << escape_html($&)
end
end
when /\A\[\[\s*([^|]*?)\s*(\|\s*(.*?))?\s*\]\]/m
str = $'
link, content = $1, $3
if uri = make_explicit_link(link)
@out << ''
if content
until content.empty?
content = parse_inline_tag(content)
end
else
@out << escape_html(link)
end
@out << ''
else
@out << escape_html($&)
end
else
str = parse_inline_tag(str)
end
end
end
def parse_inline_tag(str)
case str
when /\A\{\{\{(.*?\}*)\}\}\}/
@out << '' << escape_html($1) << ''
when /\A\{\{\s*(.*?)\s*(\|\s*(.*?)\s*)?\}\}/
if uri = make_image_link($1)
@out << make_image(uri, $3)
else
@out << escape_html($&)
end
when /\A([:alpha:]|[:digit:])+/
@out << $&
when /\A\s+/
@out << ' ' if @out[-1] != ?\s
when /\A\*\*/
toggle_tag 'strong', $&
when /\A\/\//
toggle_tag 'em', $&
when /\A\\\\/
@out << '
'
else
if @extensions
case str
when /\A__/
toggle_tag 'u', $&
when /\A\-\-/
toggle_tag 'del', $&
when /\A\+\+/
toggle_tag 'ins', $&
when /\A\^\^/
toggle_tag 'sup', $&
when /\A\~\~/
toggle_tag 'sub', $&
when /\A\(R\)/i
@out << '®'
when /\A\(C\)/i
@out << '©'
when /\A~([^\s])/
@out << escape_html($1)
when /./
@out << escape_html($&)
end
else
case str
when /\A~([^\s])/
@out << escape_html($1)
when /./
@out << escape_html($&)
end
end
end
return $'
end
def parse_table_row(str)
@out << ''
str.scan(/\s*\|(=)?\s*((\[\[.*?\]\]|\{\{.*?\}\}|[^|~]|~.)*)(?=\||$)/) do
if !$2.empty? || !$'.empty?
@out << ($1 ? '| ' : ' | ')
parse_inline($2) if $2
end_tag while @stack.last != 'table'
@out << ($1 ? '' : ' | ')
end
end
@out << '
'
end
def make_nowikiblock(input)
input.gsub(/^ (?=\}\}\})/, '')
end
def ulol?(x); x == 'ul' || x == 'ol'; end
def parse_block(str)
until str.empty?
case str
when /\A\{\{\{\r?\n(.*?)\r?\n\}\}\}/m
end_paragraph
nowikiblock = make_nowikiblock($1)
@out << '' << escape_html(nowikiblock) << '
'
when /\A\s*-{4,}\s*$/
end_paragraph
@out << '
'
when /\A\s*(={1,6})\s*(.*?)\s*=*\s*$(\r?\n)?/
end_paragraph
level = $1.size
@out << make_headline(level, $2)
when /\A[ \t]*\|.*$(\r?\n)?/
if !@stack.include?('table')
end_paragraph
start_tag('table')
end
parse_table_row($&)
when /\A\s*$(\r?\n)?/
end_paragraph
when /\A(\s*([*#]+)\s*(.*?))$(\r?\n)?/
line, bullet, item = $1, $2, $3
tag = (bullet[0,1] == '*' ? 'ul' : 'ol')
if bullet[0,1] == '#' || bullet.size != 2 || @stack.find {|x| ulol?(x) }
count = @stack.select { |x| ulol?(x) }.size
while !@stack.empty? && count > bullet.size
count -= 1 if ulol?(@stack.last)
end_tag
end
end_tag while !@stack.empty? && @stack.last != 'li'
if @stack.last == 'li' && count == bullet.size
end_tag
if @stack.last != tag
end_tag
count -= 1
end
end
while count < bullet.size
start_tag tag
count += 1
start_tag 'li' if count < bullet.size
end
@p = true
start_tag('li')
parse_inline(item)
else
start_paragraph
parse_inline(line)
end
when /\A([ \t]*\S+.*?)$(\r?\n)?/
start_paragraph
parse_inline($1)
else
raise "Parse error at #{str[0,30].inspect}"
end
#p [$&, $']
str = $'
end
end_paragraph
@out
end
end
end