gitlab-org--gitlab-foss/app/helpers/gitlab_markdown_helper.rb
2015-12-16 13:44:50 +01:00

194 lines
6.2 KiB
Ruby

require 'nokogiri'
module GitlabMarkdownHelper
# Use this in places where you would normally use link_to(gfm(...), ...).
#
# It solves a problem occurring with nested links (i.e.
# "<a>outer text <a>gfm ref</a> more outer text</a>"). This will not be
# interpreted as intended. Browsers will parse something like
# "<a>outer text </a><a>gfm ref</a> more outer text" (notice the last part is
# not linked any more). link_to_gfm corrects that. It wraps all parts to
# explicitly produce the correct linking behavior (i.e.
# "<a>outer text </a><a>gfm ref</a><a> more outer text</a>").
def link_to_gfm(body, url, html_options = {})
return "" if body.blank?
escaped_body = if body =~ /\A\<img/
body
else
escape_once(body)
end
user = current_user if defined?(current_user)
gfm_body = Banzai.render(escaped_body, project: @project, current_user: user, pipeline: :single_line)
fragment = Nokogiri::HTML::DocumentFragment.parse(gfm_body)
if fragment.children.size == 1 && fragment.children[0].name == 'a'
# Fragment has only one node, and it's a link generated by `gfm`.
# Replace it with our requested link.
text = fragment.children[0].text
fragment.children[0].replace(link_to(text, url, html_options))
else
# Traverse the fragment's first generation of children looking for pure
# text, wrapping anything found in the requested link
fragment.children.each do |node|
next unless node.text?
node.replace(link_to(node.text, url, html_options))
end
end
# Add any custom CSS classes to the GFM-generated reference links
if html_options[:class]
fragment.css('a.gfm').add_class(html_options[:class])
end
fragment.to_html.html_safe
end
def markdown(text, context = {})
return "" unless text.present?
context[:project] ||= @project
html = Banzai.render(text, context)
context.merge!(
current_user: (current_user if defined?(current_user)),
# RelativeLinkFilter
requested_path: @path,
project_wiki: @project_wiki,
ref: @ref
)
Banzai.post_process(html, context)
end
def asciidoc(text)
Gitlab::Asciidoc.render(
text,
project: @project,
current_user: (current_user if defined?(current_user)),
# RelativeLinkFilter
project_wiki: @project_wiki,
requested_path: @path,
ref: @ref,
commit: @commit
)
end
# Return the first line of +text+, up to +max_chars+, after parsing the line
# as Markdown. HTML tags in the parsed output are not counted toward the
# +max_chars+ limit. If the length limit falls within a tag's contents, then
# the tag contents are truncated without removing the closing tag.
def first_line_in_markdown(text, max_chars = nil, options = {})
md = markdown(text, options).strip
truncate_visible(md, max_chars || md.length) if md.present?
end
def render_wiki_content(wiki_page)
case wiki_page.format
when :markdown
markdown(wiki_page.content)
when :asciidoc
asciidoc(wiki_page.content)
else
wiki_page.formatted_content.html_safe
end
end
MARKDOWN_TIPS = [
"End a line with two or more spaces for a line-break, or soft-return",
"Inline code can be denoted by `surrounding it with backticks`",
"Blocks of code can be denoted by three backticks ``` or four leading spaces",
"Emoji can be added by :emoji_name:, for example :thumbsup:",
"Notify other participants using @user_name",
"Notify a specific group using @group_name",
"Notify the entire team using @all",
"Reference an issue using a hash, for example issue #123",
"Reference a merge request using an exclamation point, for example MR !123",
"Italicize words or phrases using *asterisks* or _underscores_",
"Bold words or phrases using **double asterisks** or __double underscores__",
"Strikethrough words or phrases using ~~two tildes~~",
"Make a bulleted list using + pluses, - minuses, or * asterisks",
"Denote blockquotes using > at the beginning of a line",
"Make a horizontal line using three or more hyphens ---, asterisks ***, or underscores ___"
].freeze
# Returns a random markdown tip for use as a textarea placeholder
def random_markdown_tip
MARKDOWN_TIPS.sample
end
private
# Return +text+, truncated to +max_chars+ characters, excluding any HTML
# tags.
def truncate_visible(text, max_chars)
doc = Nokogiri::HTML.fragment(text)
content_length = 0
truncated = false
doc.traverse do |node|
if node.text? || node.content.empty?
if truncated
node.remove
next
end
# Handle line breaks within a node
if node.content.strip.lines.length > 1
node.content = "#{node.content.lines.first.chomp}..."
truncated = true
end
num_remaining = max_chars - content_length
if node.content.length > num_remaining
node.content = node.content.truncate(num_remaining)
truncated = true
end
content_length += node.content.length
end
truncated = truncate_if_block(node, truncated)
end
doc.to_html
end
# Used by #truncate_visible. If +node+ is the first block element, and the
# text hasn't already been truncated, then append "..." to the node contents
# and return true. Otherwise return false.
def truncate_if_block(node, truncated)
if node.element? && node.description.block? && !truncated
node.inner_html = "#{node.inner_html}..." if node.next_sibling
true
else
truncated
end
end
# Returns the text necessary to reference `entity` across projects
#
# project - Project to reference
# entity - Object that responds to `to_reference`
#
# Examples:
#
# cross_project_reference(project, project.issues.first)
# # => 'namespace1/project1#123'
#
# cross_project_reference(project, project.merge_requests.first)
# # => 'namespace1/project1!345'
#
# Returns a String
def cross_project_reference(project, entity)
if entity.respond_to?(:to_reference)
"#{project.to_reference}#{entity.to_reference}"
else
''
end
end
end