1 files changed, 27 insertions, 0 deletions
diff --git a/lib/gitlab/string_placeholder_replacer.rb b/lib/gitlab/string_placeholder_replacer.rb
new file mode 100644
index 00000000000..9a2219b7d77
--- /dev/null
+++ b/lib/gitlab/string_placeholder_replacer.rb
@@ -0,0 +1,27 @@
+module Gitlab
+  class StringPlaceholderReplacer
+    # This method accepts the following paras
+    # - string: the string to be analyzed
+    # - placeholder_regex: i.e. /%{project_path|project_id|default_branch|commit_sha}/
+    # - block: this block will be called with each placeholder found in the string using
+    # the placeholder regex. If the result of the block is nil, the original
+    # placeholder will be returned.
+
+    def self.replace_string_placeholders(string, placeholder_regex = nil, &block)
+      return string if string.blank? || placeholder_regex.blank? || !block_given?
+
+      replace_placeholders(string, placeholder_regex, &block)
+    end
+
+    class << self
+      private
+
+      # If the result of the block is nil, then the placeholder is returned
+      def replace_placeholders(string, placeholder_regex, &block)
+        string.gsub(/%{(#{placeholder_regex})}/) do |arg|
+          yield($~[1]) || arg
+        end
+      end
+    end
+  end
+end