use traitlet for highlight_class

IPython/nbconvert/transformers/csshtmlheader.py

@@ -1,106 +1,111 b''
 """Module that pre-processes the notebook for export to HTML.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import io
 
 from pygments.formatters import HtmlFormatter
         
 from IPython.utils import path
 
 from .activatable import ActivatableTransformer
         
+from IPython.utils.traitlets import Unicode
+        
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class CSSHtmlHeaderTransformer(ActivatableTransformer):
     """
     Transformer used to pre-process notebook for HTML output.  Adds IPython notebook
     front-end CSS and Pygments CSS to HTML output.
     """
 
     header = []
 
+    highlight_class = Unicode('highlight', config=True,
+                              help="CSS highlight class identifier")
+
     def __init__(self, config=None, **kw):
         """
         Public constructor
         
         Parameters
         ----------
         config : Config
             Configuration file structure
         **kw : misc
             Additional arguments
         """
         
         super(CSSHtmlHeaderTransformer, self).__init__(config=config, **kw)
 
         if self.enabled :
             self._regen_header()
 
 
     def __call__(self, nb, resources):
         """Fetch and add CSS to the resource dictionary
 
         Fetch CSS from IPython and Pygments to add at the beginning
         of the html files.  Add this css in resources in the 
         "inlining.css" key
         
         Parameters
         ----------
         nb : NotebookNode
             Notebook being converted
         resources : dictionary
             Additional resources used in the conversion process.  Allows
             transformers to pass variables into the Jinja engine.
         """
         
         resources['inlining'] = {}
         resources['inlining']['css'] = self.header
         
         return nb, resources
 
 
     def _regen_header(self):
         """ 
         Fills self.header with lines of CSS extracted from IPython 
         and Pygments.
         """
         
         #Clear existing header.
         header = []
         
         #Construct path to IPy CSS
         sheet_filename = os.path.join(path.get_ipython_package_dir(), 
             'html', 'static', 'style', 'style.min.css')
         
         #Load style CSS file.
         try:
             with io.open(sheet_filename, encoding='utf-8') as file:
                 file_text = file.read()
                 header.append(file_text)
         except IOError:
             
             # New version of IPython with style.min.css, pass
             pass
 
         #Add pygments CSS
-        highlight_class = '.' + self.config.get('highlight_class', 'highlight')
-        pygments_css = HtmlFormatter().get_style_defs(highlight_class)
+        formatter = HtmlFormatter()
+        pygments_css = formatter.get_style_defs('.' + self.highlight_class)
         header.append(pygments_css)
 
         #Set header        
         self.header = header