converters/markdown.py

"""Converter implementing Markdown export.

Implements a Converter that allows IPython notebooks to reasonably rendered
as a Markdown document.
"""
#-----------------------------------------------------------------------------
# Copyright (c) 2012, 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
#-----------------------------------------------------------------------------

# Our own imports
from converters.base import Converter
from converters.utils import highlight, remove_ansi
from IPython.utils.text import indent


#-----------------------------------------------------------------------------
# Class declarations
#-----------------------------------------------------------------------------
class ConverterMarkdown(Converter):
    #-------------------------------------------------------------------------
    # Class-level attributes determining the behaviour of the class but
    # probably not varying from instance to instance.
    #-------------------------------------------------------------------------
    extension = 'md'
    #-------------------------------------------------------------------------
    # Instance-level attributes that are set in the constructor for this
    # class.
    #-------------------------------------------------------------------------
    # show_prompts controls the display of In[} and Out[] prompts for code
    # cells.
    show_prompts = False
    # If inline_prompt is False, display prompts on a separate line.
    inline_prompt = False

    def __init__(self, infile, highlight_source=True, show_prompts=False,
                 inline_prompt=False):
        super(ConverterMarkdown, self).__init__(infile)
        self.highlight_source = highlight_source
        self.show_prompts = show_prompts
        self.inline_prompt = inline_prompt

    def render_heading(self, cell):
        return ['{0} {1}'.format('#' * cell.level, cell.source), '']

    def render_code(self, cell):
        if not cell.input:
            return []
        lines = []
        n = self._get_prompt_number(cell)
        if self.show_prompts:
            if not self.inline_prompt:
                lines.extend(['*In[%s]:*' % n, ''])
            else:
                prompt = 'In[%s]: ' % n
                input_lines = cell.input.split('\n')
                src = (prompt + input_lines[0] + '\n' +
                       indent('\n'.join(input_lines[1:]), nspaces=len(prompt)))
        else:
            src = cell.input
        src = highlight(src) if self.highlight_source else indent(src)
        lines.extend([src, ''])
        if cell.outputs and self.show_prompts and not self.inline_prompt:
            lines.extend(['*Out[%s]:*' % n, ''])
        for output in cell.outputs:
            conv_fn = self.dispatch(output.output_type)
            lines.extend(conv_fn(output))

        #lines.append('----')
        lines.append('')
        return lines

    def render_markdown(self, cell):
        return [cell.source, '']

    def render_raw(self, cell):
        if self.raw_as_verbatim:
            return [indent(cell.source), '']
        else:
            return [cell.source, '']

    def render_pyout(self, output):
        lines = []

        ## if 'text' in output:
        ##     lines.extend(['*Out[%s]:*' % self._get_prompt_number(cell), ''])

        # output is a dictionary like object with type as a key
        if 'latex' in output:
            pass

        if 'text' in output:
            lines.extend(['<pre>', indent(output.text), '</pre>'])

        lines.append('')
        return lines

    def render_pyerr(self, output):
        # Note: a traceback is a *list* of frames.
        return [indent(remove_ansi('\n'.join(output.traceback))), '']

    def _img_lines(self, img_file):
        return ['', '![](%s)' % img_file, '']

    def render_display_format_text(self, output):
        return [indent(output.text)]

    def _unknown_lines(self, data):
        return ['Warning: Unknown cell', data]

    def render_display_format_html(self, output):
        return [output.html]

    def render_display_format_latex(self, output):
        return ['LaTeX::', indent(output.latex)]

    def render_display_format_json(self, output):
        return ['JSON:', indent(output.json)]

    def render_display_format_javascript(self, output):
        return ['JavaScript:', indent(output.javascript)]