gistfile1.rb

class ChangeInPathsTrigger

  def initialize(triggered_project, triggered_paths)
    @triggered_project = triggered_project
    @triggered_paths = triggered_paths
  end

  def build_necessary?(reasons)
    p = @triggered_project
    p.notify :polling_source_control

    p.source_control.execute_in_local_copy(["git", "fetch"], {})
    @triggered_paths.each do |path|
      p.source_control.execute_in_local_copy(["git", "diff", "origin/master", "--", path], {}) do |io|
        lines = io.readlines
        if not lines.empty?
          p.notify :new_revisions_detected, []
          return true
        end
      end
    end

    return false
  end

end