Alternative way to make anchor_link_text configurable

Closes jupytergh-412, alternative to jupytergh-520

nbconvert/exporters/html.py

@@ -5,10 +5,11 @@
 
 import os
 
-from traitlets import default
+from traitlets import default, Unicode
 from traitlets.config import Config
 
 from nbconvert.filters.highlight import Highlight2HTML
+from nbconvert.filters.markdown_mistune import IPythonRenderer, MarkdownWithMath
 
 from .templateexporter import TemplateExporter
 
@@ -21,6 +22,9 @@ class HTMLExporter(TemplateExporter):
     filters, just change the 'template_file' config option.
     """
 
+    anchor_link_text = Unicode(u'¶',
+        help="The text used as the text for anchor links.").tag(config=True)
+
     @default('file_extension')
     def _file_extension_default(self):
         return '.html'
@@ -61,6 +65,17 @@ def default_config(self):
         c.merge(super(HTMLExporter,self).default_config)
         return c
 
+    def markdown2html(self, source):
+        """Markdown to HTML filter respecting the anchor_link_text setting"""
+        renderer = IPythonRenderer(escape=False,
+                                   anchor_link_text=self.anchor_link_text)
+        return MarkdownWithMath(renderer=renderer).render(source)
+
+    def default_filters(self):
+        for pair in super(HTMLExporter, self).default_filters():
+            yield pair
+        yield ('markdown2html', self.markdown2html)
+
     def from_notebook_node(self, nb, resources=None, **kw):
         langinfo = nb.metadata.get('language_info', {})
         lexer = langinfo.get('pygments_lexer', langinfo.get('name', None))

nbconvert/filters/markdown_mistune.py

@@ -102,7 +102,8 @@ def block_code(self, code, lang):
 
     def header(self, text, level, raw=None):
         html = super(IPythonRenderer, self).header(text, level, raw=raw)
-        return add_anchor(html)
+        anchor_link_text = self.options.get('anchor_link_text', u'¶')
+        return add_anchor(html, anchor_link_text=anchor_link_text)
 
     # Pass math through unaltered - mathjax does the rendering in the browser
     def block_math(self, text):

nbconvert/filters/strings.py

@@ -86,7 +86,7 @@ def _convert_header_id(header_contents):
     """
     return header_contents.replace(' ', '-')
 
-def add_anchor(html):
+def add_anchor(html, anchor_link_text=u'¶'):
     """Add an id and an anchor-link to an html header
     
     For use on markdown headings
@@ -99,7 +99,7 @@ def add_anchor(html):
     link = _convert_header_id(html2text(h))
     h.set('id', link)
     a = ElementTree.Element("a", {"class" : "anchor-link", "href" : "#" + link})
-    a.text = u'¶'
+    a.text = anchor_link_text
     h.append(a)
 
     # Known issue of Python3.x, ElementTree.tostring() returns a byte string