"""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 io import os import inspect import types import copy import collections import datetime # other libs/dependencies from jinja2 import Environment, FileSystemLoader, ChoiceLoader # IPython imports from IPython.config.configurable import Configurable from IPython.config import Config from IPython.nbformat import current as nbformat from IPython.utils.traitlets import MetaHasTraits, DottedObjectName, Unicode, List, Dict from IPython.utils.importstring import import_item from IPython.utils.text import indent from IPython.nbconvert import transformers as nbtransformers from IPython.nbconvert import filters #----------------------------------------------------------------------------- # Globals and constants #----------------------------------------------------------------------------- #Jinja2 extensions to load. JINJA_EXTENSIONS = ['jinja2.ext.loopcontrols'] default_filters = { 'indent': indent, 'markdown': filters.markdown2html, 'ansi2html': filters.ansi2html, 'filter_data_type': filters.DataTypeFilter, 'get_lines': filters.get_lines, 'highlight': filters.highlight, 'highlight2html': filters.highlight, 'highlight2latex': filters.highlight2latex, 'markdown2latex': filters.markdown2latex, 'markdown2rst': filters.markdown2rst, 'pycomment': filters.python_comment, 'rm_ansi': filters.remove_ansi, 'rm_dollars': filters.strip_dollars, 'rm_fake': filters.rm_fake, 'ansi2latex': filters.ansi2latex, 'rm_math_space': filters.rm_math_space, 'wrap': filters.wrap } #----------------------------------------------------------------------------- # Class #----------------------------------------------------------------------------- class Exporter(Configurable): """ 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/transformers. If the filters/ transformers 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( '', config=True, help="Name of the template file to use") file_extension = Unicode( 'txt', config=True, help="Extension of the file that should be written to disk" ) template_path = Unicode( os.path.join("..", "templates"), config=True, help="Path where the template files are located.") template_skeleton_path = Unicode( os.path.join("..", "templates", "skeleton"), config=True, 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) #Configurability, allows the user to easily add filters and transformers. transformers = List(config=True, help="""List of transformers, by name or namespace, to enable.""") filters = Dict(config=True, help="""Dictionary of filters, by name and namespace, to add to the Jinja environment.""") default_transformers = List([nbtransformers.coalesce_streams, nbtransformers.ExtractFigureTransformer], config=True, help="""List of transformers available by default, by name, namespace, instance, or type.""") 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 loder to find templates. Will be tried in order before the default FileSysteme ones. """ #Call the base class constructor c = self.default_config if config: c.merge(config) super(Exporter, self).__init__(config=c, **kw) #Init self._init_environment(extra_loaders=extra_loaders) self._init_transformers() self._init_filters() @property def default_config(self): return Config() 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 transformers and filters. """ nb_copy = copy.deepcopy(nb) resources = self._init_resources(resources) #Preprocess nb_copy, resources = self._transform(nb_copy, resources) #Convert self.template = self.environment.get_template(self.template_file + self.template_extension) output = self.template.render(nb=nb_copy, resources=resources) return output, resources def from_filename(self, filename, resources=None, **kw): """ Convert a notebook from a notebook file. Parameters ---------- filename : str Full filename of the notebook file to open and convert. """ #Pull the metadata from the filesystem. if not 'metadata' in resources: resources['metadata'] = ResourcesDict() basename = os.path.basename(filename) notebook_name = basename[:basename.rfind('.')] resources['metadata']['name'] = notebook_name modified_date = datetime.datetime.fromtimestamp(os.path.getmtime(filename)) resources['metadata']['modified_date'] = modified_date.strftime("%B %-d, %Y") with io.open(filename) as f: return self.from_notebook_node(nbformat.read(f, 'json'), resources=resources,**kw) def from_file(self, file_stream, resources=None, **kw): """ Convert a notebook from a notebook file. Parameters ---------- file_stream : file-like object Notebook file-like object to convert. """ return self.from_notebook_node(nbformat.read(file_stream, 'json'), resources=resources, **kw) def register_transformer(self, transformer, enabled=None): """ Register a transformer. Transformers are classes that act upon the notebook before it is passed into the Jinja templating engine. Transformers are also capable of passing additional information to the Jinja templating engine. Parameters ---------- transformer : transformer """ #Handle transformer's registration based on it's type if inspect.isfunction(transformer): #Transformer is a function, no need to construct it. self._transformers.append(transformer) return transformer elif isinstance(transformer, types.StringTypes): #Transformer is a string, import the namespace and recursively call #this register_transformer method transformer_cls = import_item(DottedObjectName(transformer)) return self.register_transformer(transformer_cls, enabled=None) elif isinstance(transformer, MetaHasTraits): #Transformer is configurable. Make sure to pass in new default for #the enabled flag if one was specified. transformer_instance = transformer(parent=self) if enabled is not None: transformer_instance.enabled = True else: #Transformer is not configurable, construct it transformer_instance = transformer() #Register and return the transformer. self._transformers.append(transformer_instance) return transformer_instance def register_filter(self, name, 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 inspect.isfunction(filter): self.environment.filters[name] = filter elif isinstance(filter, types.StringTypes): filter_cls = import_item(DottedObjectName(filter)) self.register_filter(name, filter_cls) elif isinstance(filter, MetaHasTraits): self.environment.filters[name] = filter(config=self.config) else: self.environment.filters[name] = filter() return self.environment.filters[name] 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) loaders.append(FileSystemLoader([ os.path.join(here, self.template_path), os.path.join(here, self.template_skeleton_path), ])) 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_transformers(self): """ Register all of the transformers needed for this exporter, disabled unless specified explicitly. """ self._transformers = [] #Load default transformers (not necessarly enabled by default). if self.default_transformers: for transformer in self.default_transformers: self.register_transformer(transformer) #Load user transformers. Enable by default. if self.transformers: for transformer in self.transformers: self.register_transformer(transformer, enabled=True) 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.iteritems(): self.register_filter(key, value) #Load user filters. Overwrite existing filters if need be. if self.filters: for key, user_filter in self.filters.iteritems(): self.register_filter(key, user_filter) def _init_resources(self, resources): #Make sure the resources dict is of ResourcesDict type. if resources is None: resources = ResourcesDict() if not isinstance(resources, ResourcesDict): new_resources = ResourcesDict() new_resources.update(resources) resources = new_resources #Make sure the metadata extension exists in resources if 'metadata' in resources: if not isinstance(resources['metadata'], ResourcesDict): resources['metadata'] = ResourcesDict(resources['metadata']) else: resources['metadata'] = ResourcesDict() resources['metadata']['name'] = 'Notebook' resources['metadata']['modified_date'] = '' #Set the output extension resources['output_extension'] = self.file_extension return resources def _transform(self, nb, resources): """ Preprocess the notebook before passing it into the Jinja engine. To preprocess the notebook is to apply all of the Parameters ---------- nb : notebook node notebook that is being exported. resources : a dict of additional resources that can be accessed read/write by transformers and filters. """ # Do a deepcopy first, # we are never safe enough with what the transformers could do. nbc = deepcopy(nb) resc = deepcopy(resources) #Run each transformer on the notebook. Carry the output along #to each transformer for transformer in self._transformers: nbc, resc = transformer(nbc, resc) return nbc, resc