footnote back and forth navigation

1 files changed, 15 insertions, 2 deletions

diff --git a/megapixels/app/site/parser.py b/megapixels/app/site/parser.py
index ef83b655..9e904e00 100644
--- a/megapixels/app/site/parser.py
+++ b/megapixels/app/site/parser.py
@@ -10,6 +10,8 @@ import app.site.s3 as s3
 renderer = mistune.Renderer(escape=False)
 markdown = mistune.Markdown(renderer=renderer)
 
+footnote_count = 0
+
 def parse_markdown(metadata, sections, s3_path, skip_h1=False):
   """
   parse page into sections, preprocess the markdown to handle our modifications
@@ -94,7 +96,18 @@ def parse_markdown(metadata, sections, s3_path, skip_h1=False):
 
   if footnote_lookup:
     for key, index in footnote_lookup.items():
-      content = content.replace(key, '<a href="#{}" class="footnote" title="Footnote {}">{}</a>'.format(key, index, index))
+      global footnote_count
+      footnote_count = 0
+      letters = "abcdefghijklmnopqrstuvwxyz"
+      footnote_backlinks = []
+      def footnote_tag(match):
+        global footnote_count
+        footnote_count += 1
+        footnote_backlinks.append('<a href="#{}_{}">{}</a>'.format(key, footnote_count, letters[footnote_count-1]))
+        return '<a class="footnote_shim" name="{}_{}"> </a><a href="#{}" class="footnote" title="Footnote {}">{}</a>'.format(key, footnote_count, key, index, index)
+      key_regex = re.compile(key.replace('[', '\\[').replace('^', '\\^').replace(']', '\\]'))
+      content = key_regex.sub(footnote_tag, content)
+      footnote_txt = footnote_txt.replace("{}_BACKLINKS".format(index), "".join(footnote_backlinks))
     content += footnote_txt
   return content
 
@@ -197,7 +210,7 @@ def format_footnotes(footnotes, s3_path):
       continue
     key, note = footnote.split(': ', 1)
     footnote_index_lookup[key] = index
-    footnote_list.append('<a name="{}" class="footnote_anchor">^</a>'.format(key) + markdown(note))
+    footnote_list.append('<a name="{}" class="footnote_shim"></a><span class="backlinks">{}_BACKLINKS</span>'.format(key, index) + markdown(note))
     index += 1
 
   footnote_txt = '<section><ul class="footnotes"><li>' + '</li><li>'.join(footnote_list) + '</li></ul></section>'