lib/gitlab/markdown.rb
module Gitlab
# Custom parser for GitLab-flavored Markdown
#
# It replaces references in the text with links to the appropriate items in
# GitLab.
#
# Supported reference formats are:
# * @foo for team members
# * #123 for issues
# * #JIRA-123 for Jira issues
# * !123 for merge requests
# * $123 for snippets
# * 123456 for commits
#
# It also parses Emoji codes to insert images. See
# http://www.emoji-cheat-sheet.com/ for a list of the supported icons.
#
# Examples
#
# >> gfm("Hey @david, can you fix this?")
# => "Hey <a href="/u/david">@david</a>, can you fix this?"
#
# >> gfm("Commit 35d5f7c closes #1234")
# => "Commit <a href="/gitlab/commits/35d5f7c">35d5f7c</a> closes <a href="/gitlab/issues/1234">#1234</a>"
#
# >> gfm(":trollface:")
# => "<img alt=\":trollface:\" class=\"emoji\" src=\"/images/trollface.png" title=\":trollface:\" />
module Markdown
include IssuesHelper
attr_reader :html_options
# Public: Parse the provided text with GitLab-Flavored Markdown
#
# text - the source text
# html_options - extra options for the reference links as given to link_to
#
# Note: reference links will only be generated if @project is set
def gfm(text, html_options = {})
return text if text.nil?
# Duplicate the string so we don't alter the original, then call to_str
# to cast it back to a String instead of a SafeBuffer. This is required
# for gsub calls to work as we need them to.
text = text.dup.to_str
@html_options = html_options
# Extract pre blocks so they are not altered
# from http://github.github.com/github-flavored-markdown/
text.gsub!(%r{<pre>.*?</pre>|<code>.*?</code>}m) { |match| extract_piece(match) }
# Extract links with probably parsable hrefs
text.gsub!(%r{<a.*?>.*?</a>}m) { |match| extract_piece(match) }
# Extract images with probably parsable src
text.gsub!(%r{<img.*?>}m) { |match| extract_piece(match) }
# TODO: add popups with additional information
text = parse(text)
# Insert pre block extractions
text.gsub!(/\{gfm-extraction-(\h{32})\}/) do
insert_piece($1)
end
sanitize text.html_safe, attributes: ActionView::Base.sanitized_allowed_attributes + %w(id class), tags: ActionView::Base.sanitized_allowed_tags + %w(table tr td th)
end
private
def extract_piece(text)
@extractions ||= {}
md5 = Digest::MD5.hexdigest(text)
@extractions[md5] = text
"{gfm-extraction-#{md5}}"
end
def insert_piece(id)
@extractions[id]
end
# Private: Parses text for references and emoji
#
# text - Text to parse
#
# Note: reference links will only be generated if @project is set
#
# Returns parsed text
def parse(text)
parse_references(text) if @project
parse_emoji(text)
text
end
REFERENCE_PATTERN = %r{
(?<prefix>\W)? # Prefix
( # Reference
@(?<user>[a-zA-Z][a-zA-Z0-9_\-\.]*) # User name
|\#(?<issue>([a-zA-Z]+-)?\d+) # Issue ID
|!(?<merge_request>\d+) # MR ID
|\$(?<snippet>\d+) # Snippet ID
|(?<commit>[\h]{6,40}) # Commit ID
|(?<skip>gfm-extraction-[\h]{6,40}) # Skip gfm extractions. Otherwise will be parsed as commit
)
(?<suffix>\W)? # Suffix
}x.freeze
TYPES = [:user, :issue, :merge_request, :snippet, :commit].freeze
def parse_references(text)
# parse reference links
text.gsub!(REFERENCE_PATTERN) do |match|
prefix = $~[:prefix]
suffix = $~[:suffix]
type = TYPES.select{|t| !$~[t].nil?}.first
if type
identifier = $~[type]
# Avoid HTML entities
if prefix && suffix && prefix[0] == '&' && suffix[-1] == ';'
match
elsif ref_link = reference_link(type, identifier)
"#{prefix}#{ref_link}#{suffix}"
else
match
end
else
match
end
end
end
EMOJI_PATTERN = %r{(:(\S+):)}.freeze
def parse_emoji(text)
# parse emoji
text.gsub!(EMOJI_PATTERN) do |match|
if valid_emoji?($2)
image_tag(url_to_image("emoji/#{$2}.png"), class: 'emoji', title: $1, alt: $1, size: "20x20")
else
match
end
end
end
# Private: Checks if an emoji icon exists in the image asset directory
#
# emoji - Identifier of the emoji as a string (e.g., "+1", "heart")
#
# Returns boolean
def valid_emoji?(emoji)
Emoji.names.include? emoji
end
# Private: Dispatches to a dedicated processing method based on reference
#
# reference - Object reference ("@1234", "!567", etc.)
# identifier - Object identifier (Issue ID, SHA hash, etc.)
#
# Returns string rendered by the processing method
def reference_link(type, identifier)
send("reference_#{type}", identifier)
end
def reference_user(identifier)
if member = @project.team_members.find { |user| user.username == identifier }
link_to("@#{identifier}", user_url(identifier), html_options.merge(class: "gfm gfm-team_member #{html_options[:class]}")) if member
end
end
def reference_issue(identifier)
if @project.issue_exists? identifier
url = url_for_issue(identifier)
title = title_for_issue(identifier)
link_to("##{identifier}", url, html_options.merge(title: "Issue: #{title}", class: "gfm gfm-issue #{html_options[:class]}"))
end
end
def reference_merge_request(identifier)
if merge_request = @project.merge_requests.where(iid: identifier).first
link_to("!#{identifier}", project_merge_request_url(@project, merge_request), html_options.merge(title: "Merge Request: #{merge_request.title}", class: "gfm gfm-merge_request #{html_options[:class]}"))
end
end
def reference_snippet(identifier)
if snippet = @project.snippets.where(id: identifier).first
link_to("$#{identifier}", project_snippet_url(@project, snippet), html_options.merge(title: "Snippet: #{snippet.title}", class: "gfm gfm-snippet #{html_options[:class]}"))
end
end
def reference_commit(identifier)
if @project.valid_repo? && commit = @project.repository.commit(identifier)
link_to(identifier, project_commit_url(@project, commit), html_options.merge(title: commit.link_title, class: "gfm gfm-commit #{html_options[:class]}"))
end
end
end
end