module Gitlab module Gfm ## # Class that unfolds local references in text. # # The initializer takes text in Markdown and project this text is valid # in context of. # # `unfold` method tries to find all local references and unfold each of # those local references to cross reference format, assuming that the # argument passed to this method is a project that references will be # viewed from (see `Referable#to_reference method). # # Examples: # # 'Hello, this issue is related to #123 and # other issues labeled with ~"label"', will be converted to: # # 'Hello, this issue is related to gitlab-org/gitlab-ce#123 and # other issue labeled with gitlab-org/gitlab-ce~"label"'. # # It does respect markdown lexical rules, so text in code block will not be # replaced, see another example: # # 'Merge request for issue #1234, see also link: # http://gitlab.com/some/link/#1234, and code `puts #1234`' => # # 'Merge request for issue gitlab-org/gitlab-ce#1234, se also link: # http://gitlab.com/some/link/#1234, and code `puts #1234`' # class ReferenceRewriter RewriteError = Class.new(StandardError) def initialize(text, source_project, current_user) @text = text @source_project = source_project @current_user = current_user @original_html = markdown(text) @pattern = Gitlab::ReferenceExtractor.references_pattern end def rewrite(target_project) return @text unless needs_rewrite? @text.gsub(@pattern) do |reference| unfold_reference(reference, Regexp.last_match, target_project) end end def needs_rewrite? @text =~ @pattern end private def unfold_reference(reference, match, target_project) before = @text[0...match.begin(0)] after = @text[match.end(0)..-1] referable = find_referable(reference) return reference unless referable cross_reference = build_cross_reference(referable, target_project) return reference if reference == cross_reference if cross_reference.nil? raise RewriteError, "Unspecified reference detected for #{referable.class.name}" end new_text = before + cross_reference + after substitution_valid?(new_text) ? cross_reference : reference end def find_referable(reference) extractor = Gitlab::ReferenceExtractor.new(@source_project, @current_user) extractor.analyze(reference) extractor.all.first end def build_cross_reference(referable, target_project) if referable.respond_to?(:project) referable.to_reference(target_project) else referable.to_reference(@source_project, target_project: target_project) end end def substitution_valid?(substituted) @original_html == markdown(substituted) end def markdown(text) Banzai.render(text, project: @source_project, no_original_data: true) end end end end