1 files changed, 47 insertions, 0 deletions
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index aa3a8d7..15d5082 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2020 IN COMMON Collective <collective@incommon.cc>
+#
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
 module ApplicationHelper
   def current_agency
     current_user.agencies.where(agent: current_agent).first
@@ -21,4 +25,47 @@ module ApplicationHelper
             'map-zoom': map.zoom
           })
   end
+
+  # Markdown helper
+  # Always use all extensions. Additional parser and render options may be
+  # passed as a second argument.
+  #
+  # @param markdown (String) a string to parse as Markdown source
+  # @param options (String or Array) an optional parser/renderer option
+  # @return String HTML-formatted from Mardkown source
+  def m(markdown, options = nil)
+    tag.div(
+      CommonMarker.render_doc(
+        markdown.to_s,
+        options.to_a + default_commonmarker_options,
+        default_commonmarker_extensions
+      ).to_html.html_safe, class: 'markdown')
+  end
+
+  private
+
+  # CommonMarker extensions
+  # See https://github.com/gjtorikian/commonmarker#extensions
+  def default_commonmarker_extensions
+    [
+      :table,
+      :tasklist,
+      :strikethrough,
+      :autolink,
+      :tagfilter
+    ]
+  end
+
+  # CommonMarker options
+  # See https://github.com/gjtorikian/commonmarker#options
+  def default_commonmarker_options
+    [
+      #:HARDBREAKS, # only seems to work with render_html, but then all others
+                    # only work with render_doc
+      :FOOTNOTES,
+      :SMART,
+      :STRIKETHROUGH_DOUBLE_TILDE,
+      :VALIDATE_UTF8
+    ]
+  end
 end