make default language highlight configurable for html

IPython/nbconvert/exporters/templateexporter.py

@@ -1,315 +1,315 b''
 """This module defines Exporter, a highly configurable converter
 that uses Jinja2 to export notebook files into different formats.
 """
 
 #-----------------------------------------------------------------------------
 # 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
 #-----------------------------------------------------------------------------
 
 from __future__ import print_function, absolute_import
 
 # Stdlib imports
 import os
 
 # other libs/dependencies
 from jinja2 import Environment, FileSystemLoader, ChoiceLoader, TemplateNotFound
 
 # IPython imports
 from IPython.utils.traitlets import MetaHasTraits, Unicode, List, Dict, Any
 from IPython.utils.importstring import import_item
 from IPython.utils import py3compat, text
 
 from IPython.nbconvert import filters
 from .exporter import Exporter
 
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
 
 #Jinja2 extensions to load.
 JINJA_EXTENSIONS = ['jinja2.ext.loopcontrols']
 
 default_filters = {
         'indent': text.indent,
         'markdown2html': filters.markdown2html,
         'ansi2html': filters.ansi2html,
         'filter_data_type': filters.DataTypeFilter,
         'get_lines': filters.get_lines,
-        'highlight2html': filters.highlight2html,
+        'highlight2html': filters.Highlight2Html,
         'highlight2latex': filters.highlight2latex,
         'ipython2python': filters.ipython2python,
         'posix_path': filters.posix_path,
         'markdown2latex': filters.markdown2latex,
         'markdown2rst': filters.markdown2rst,
         'comment_lines': filters.comment_lines,
         'strip_ansi': filters.strip_ansi,
         'strip_dollars': filters.strip_dollars,
         'strip_files_prefix': filters.strip_files_prefix,
         'html2text' : filters.html2text,
         'add_anchor': filters.add_anchor,
         'ansi2latex': filters.ansi2latex,
         'wrap_text': filters.wrap_text,
         'escape_latex': filters.escape_latex,
         'citation2latex': filters.citation2latex,
         'path2url': filters.path2url,
         'add_prompts': filters.add_prompts,
 }
 
 #-----------------------------------------------------------------------------
 # Class
 #-----------------------------------------------------------------------------
 
 class TemplateExporter(Exporter):
     """
     Exports notebooks into other file formats.  Uses Jinja 2 templating engine
     to output new formats.  Inherit from this class if you are creating a new
     template type along with new filters/preprocessors.  If the filters/
     preprocessors provided by default suffice, there is no need to inherit from
     this class.  Instead, override the template_file and file_extension
     traits via a config file.
 
     {filters}
     """
     
     # finish the docstring
     __doc__ = __doc__.format(filters = '- '+'\n    - '.join(default_filters.keys()))
 
 
     template_file = Unicode(u'default',
             config=True,
             help="Name of the template file to use")
     def _template_file_changed(self, name, old, new):
         if new == 'default':
             self.template_file = self.default_template
         else:
             self.template_file = new
         self.template = None
         self._load_template()
     
     default_template = Unicode(u'')
     template = Any()
     environment = Any()
 
     template_path = List(['.'], config=True)
     def _template_path_changed(self, name, old, new):
         self._load_template()
 
     default_template_path = Unicode(
         os.path.join("..", "templates"), 
         help="Path where the template files are located.")
 
     template_skeleton_path = Unicode(
         os.path.join("..", "templates", "skeleton"), 
         help="Path where the template skeleton files are located.") 
 
     #Jinja block definitions
     jinja_comment_block_start = Unicode("", config=True)
     jinja_comment_block_end = Unicode("", config=True)
     jinja_variable_block_start = Unicode("", config=True)
     jinja_variable_block_end = Unicode("", config=True)
     jinja_logic_block_start = Unicode("", config=True)
     jinja_logic_block_end = Unicode("", config=True)
     
     #Extension that the template files use.    
     template_extension = Unicode(".tpl", config=True)
 
     filters = Dict(config=True,
         help="""Dictionary of filters, by name and namespace, to add to the Jinja
         environment.""")
 
 
     def __init__(self, config=None, extra_loaders=None, **kw):
         """
         Public constructor
     
         Parameters
         ----------
         config : config
             User configuration instance.
         extra_loaders : list[of Jinja Loaders]
             ordered list of Jinja loader to find templates. Will be tried in order
             before the default FileSystem ones.
         template : str (optional, kw arg)
             Template to use when exporting.
         """
         if not config:
             config = self.default_config
         
         super(Exporter, self).__init__(config=config, **kw)
 
         #Init
         self._init_template()
         self._init_environment(extra_loaders=extra_loaders)
         self._init_preprocessors()
         self._init_filters()
 
 
     def _load_template(self):
         """Load the Jinja template object from the template file
         
         This is a no-op if the template attribute is already defined,
         or the Jinja environment is not setup yet.
         
         This is triggered by various trait changes that would change the template.
         """
         if self.template is not None:
             return
         # called too early, do nothing
         if self.environment is None:
             return
         # Try different template names during conversion.  First try to load the
         # template by name with extension added, then try loading the template
         # as if the name is explicitly specified, then try the name as a 
         # 'flavor', and lastly just try to load the template by module name.
         module_name = self.__module__.rsplit('.', 1)[-1]
         try_names = []
         if self.template_file:
             try_names.extend([
                 self.template_file + self.template_extension,
                 self.template_file,
                 module_name + '_' + self.template_file + self.template_extension,
             ])
         try_names.append(module_name + self.template_extension)
         for try_name in try_names:
             self.log.debug("Attempting to load template %s", try_name)
             try:
                 self.template = self.environment.get_template(try_name)
             except (TemplateNotFound, IOError):
                 pass
             except Exception as e:
                 self.log.warn("Unexpected exception loading template: %s", try_name, exc_info=True)
             else:
                 self.log.info("Loaded template %s", try_name)
                 break
     
     def from_notebook_node(self, nb, resources=None, **kw):
         """
         Convert a notebook from a notebook node instance.
     
         Parameters
         ----------
         nb : Notebook node
         resources : dict (**kw) 
             of additional resources that can be accessed read/write by 
             preprocessors and filters.
         """
         nb_copy, resources = super(TemplateExporter, self).from_notebook_node(nb, resources, **kw)
 
         self._load_template()
 
         if self.template is not None:
             output = self.template.render(nb=nb_copy, resources=resources)
         else:
             raise IOError('template file "%s" could not be found' % self.template_file)
         return output, resources
 
 
     def register_filter(self, name, jinja_filter):
         """
         Register a filter.
         A filter is a function that accepts and acts on one string.  
         The filters are accesible within the Jinja templating engine.
     
         Parameters
         ----------
         name : str
             name to give the filter in the Jinja engine
         filter : filter
         """
         if jinja_filter is None:
             raise TypeError('filter')
         isclass = isinstance(jinja_filter, type)
         constructed = not isclass
 
         #Handle filter's registration based on it's type
         if constructed and isinstance(jinja_filter, py3compat.string_types):
             #filter is a string, import the namespace and recursively call
             #this register_filter method
             filter_cls = import_item(jinja_filter)
             return self.register_filter(name, filter_cls)
         
         if constructed and hasattr(jinja_filter, '__call__'):
             #filter is a function, no need to construct it.
             self.environment.filters[name] = jinja_filter
             return jinja_filter
 
         elif isclass and isinstance(jinja_filter, MetaHasTraits):
             #filter is configurable.  Make sure to pass in new default for 
             #the enabled flag if one was specified.
             filter_instance = jinja_filter(parent=self)
             self.register_filter(name, filter_instance )
 
         elif isclass:
             #filter is not configurable, construct it
             filter_instance = jinja_filter()
             self.register_filter(name, filter_instance)
 
         else:
             #filter is an instance of something without a __call__ 
             #attribute.  
             raise TypeError('filter')
 
         
     def _init_template(self):
         """
         Make sure a template name is specified.  If one isn't specified, try to
         build one from the information we know.
         """
         self._template_file_changed('template_file', self.template_file, self.template_file)
         
 
     def _init_environment(self, extra_loaders=None):
         """
         Create the Jinja templating environment.
         """
         here = os.path.dirname(os.path.realpath(__file__))
         loaders = []
         if extra_loaders:
             loaders.extend(extra_loaders)
 
         paths = self.template_path
         paths.extend([os.path.join(here, self.default_template_path),
                       os.path.join(here, self.template_skeleton_path)])
         loaders.append(FileSystemLoader(paths))
 
         self.environment = Environment(
             loader= ChoiceLoader(loaders),
             extensions=JINJA_EXTENSIONS
             )
         
         #Set special Jinja2 syntax that will not conflict with latex.
         if self.jinja_logic_block_start:
             self.environment.block_start_string = self.jinja_logic_block_start
         if self.jinja_logic_block_end:
             self.environment.block_end_string = self.jinja_logic_block_end
         if self.jinja_variable_block_start:
             self.environment.variable_start_string = self.jinja_variable_block_start
         if self.jinja_variable_block_end:
             self.environment.variable_end_string = self.jinja_variable_block_end
         if self.jinja_comment_block_start:
             self.environment.comment_start_string = self.jinja_comment_block_start
         if self.jinja_comment_block_end:
             self.environment.comment_end_string = self.jinja_comment_block_end
 
     
     def _init_filters(self):
         """
         Register all of the filters required for the exporter.
         """
         
         #Add default filters to the Jinja2 environment
         for key, value in default_filters.items():
             self.register_filter(key, value)
 
         #Load user filters.  Overwrite existing filters if need be.
         if self.filters:
             for key, user_filter in self.filters.items():
                 self.register_filter(key, user_filter)

IPython/nbconvert/filters/highlight.py

@@ -1,110 +1,118 b''
 """
 Module containing filter functions that allow code to be highlighted
 from within Jinja templates.
 """
 #-----------------------------------------------------------------------------
 # 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
 #-----------------------------------------------------------------------------
 
 from pygments import highlight as pygements_highlight
 from pygments.lexers import get_lexer_by_name
 from pygments.formatters import HtmlFormatter
 from pygments.formatters import LatexFormatter
+from IPython.config import catch_config_error, Configurable
+from IPython.utils.traitlets import Unicode
 
 # Our own imports
 from IPython.nbconvert.utils.lexers import IPythonLexer
 
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
 
 MULTILINE_OUTPUTS = ['text', 'html', 'svg', 'latex', 'javascript', 'json']
 
 #-----------------------------------------------------------------------------
 # Utility functions
 #-----------------------------------------------------------------------------
 
 __all__ = [
-    'highlight2html',
+    'Highlight2Html',
     'highlight2latex'
 ]
 
 
-def highlight2html(source, language='ipython', metadata=None):
+class Highlight2Html(Configurable):
+
+    language = Unicode('ipython', config=True, help='default highlight language')
+
+    def __call__(self, source, language=None, metadata=None):
     """
     Return a syntax-highlighted version of the input source as html output.
 
     Parameters
     ----------
     source : str
         source of the cell to highlight
     language : str
         language to highlight the syntax of
     metadata : NotebookNode cell metadata
         metadata of the cell to highlight
     """
+        if not language:
+            language=self.language
 
     return _pygment_highlight(source, HtmlFormatter(), language, metadata)
 
 
 def highlight2latex(source, language='ipython', metadata=None, strip_verbatim=False):
     """
     Return a syntax-highlighted version of the input source as latex output.
 
     Parameters
     ----------
     source : str
         source of the cell to highlight
     language : str
         language to highlight the syntax of
     metadata : NotebookNode cell metadata
         metadata of the cell to highlight
     strip_verbatim : bool
         remove the Verbatim environment that pygments provides by default
     """
     latex = _pygment_highlight(source, LatexFormatter(), language, metadata)
     if strip_verbatim:
         latex = latex.replace(r'\begin{Verbatim}[commandchars=\\\{\}]' + '\n', '')
         return latex.replace('\n\\end{Verbatim}\n', '')
     else:
         return latex
 
 
 
 def _pygment_highlight(source, output_formatter, language='ipython', metadata=None):
     """
     Return a syntax-highlighted version of the input source
 
     Parameters
     ----------
     source : str
         source of the cell to highlight
     output_formatter : Pygments formatter
     language : str
         language to highlight the syntax of
     metadata : NotebookNode cell metadata
         metadata of the cell to highlight
     """
 
     # If the cell uses a magic extension language,
     # use the magic language instead.
     if language == 'ipython' \
         and metadata \
         and 'magics_language' in metadata:
 
         language = metadata['magics_language']
 
     if language == 'ipython':
         lexer = IPythonLexer()
     else:
         lexer = get_lexer_by_name(language, stripall=True)
 
     return pygements_highlight(source, lexer, output_formatter)