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Diffstat (limited to 'lib/gitlab/gfm/reference_rewriter.rb')
-rw-r--r-- | lib/gitlab/gfm/reference_rewriter.rb | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/gitlab/gfm/reference_rewriter.rb b/lib/gitlab/gfm/reference_rewriter.rb new file mode 100644 index 00000000000..a1c6ee7bd69 --- /dev/null +++ b/lib/gitlab/gfm/reference_rewriter.rb @@ -0,0 +1,79 @@ +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 + def initialize(text, source_project, current_user) + @text = text + @source_project = source_project + @current_user = current_user + @original_html = markdown(text) + end + + def rewrite(target_project) + pattern = Gitlab::ReferenceExtractor.references_pattern + + @text.gsub(pattern) do |reference| + unfold_reference(reference, Regexp.last_match, target_project) + end + 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 = referable.to_reference(target_project) + return reference if reference == cross_reference + + 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 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 |