pyplots.py

# -*- coding: utf-8 -*-

# Copyright © 2012-2015 Roberto Alsina and others.

# Permission is hereby granted, free of charge, to any
# person obtaining a copy of this software and associated
# documentation files (the "Software"), to deal in the
# Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the
# Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice
# shall be included in all copies or substantial portions of
# the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
# PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
# OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from hashlib import md5
import io
import os

from docutils import nodes
from docutils.parsers.rst import directives
from docutils.parsers.rst.directives import images

try:
    import matplotlib
    import matplotlib._pylab_helpers
    import matplotlib.pyplot as plt
except ImportError:
    matplotlib = None

from nikola.plugin_categories import RestExtension
from nikola.utils import req_missing, makedirs

_site = None


class Plugin(RestExtension):

    name = "pyplots"

    def set_site(self, site):
        global _site
        _site = self.site = site
        directives.register_directive('plot', PyPlot)
        PyPlot.out_dir = os.path.join(site.config['OUTPUT_FOLDER'], 'pyplots')
        return super(Plugin, self).set_site(site)


pyplot_spec = images.Image.option_spec
pyplot_spec['include-source'] = directives.flag


class PyPlot(images.Image):
    """ Reimplementation of http://matplotlib.org/sampledoc/extensions.html#inserting-matplotlib-plots."""

    has_content = True
    option_spec = pyplot_spec
    optional_arguments = 1
    required_arguments = 0

    def run(self):
        if matplotlib is None:
            msg = req_missing(['matplotlib'], 'use the plot directive', optional=True)
            return [nodes.raw('', '<div class="text-error">{0}</div>'.format(msg), format='html')]

        if not self.arguments and not self.content:
            raise self.error('The plot directive needs either an argument or content.')

        if self.arguments and self.content:
            raise self.error('The plot directive needs either an argument or content, not both.')

        if self.arguments:
            plot_path = self.arguments[0]
            with io.open(plot_path, encoding='utf-8') as fd:
                data = fd.read()
        elif self.content:
            data = '\n'.join(self.content)
            plot_path = md5(data).hexdigest()

        # Always reset context
        plt.close('all')
        matplotlib.rc_file_defaults()
        # Run plot
        exec(data)

        out_path = os.path.join(self.out_dir, plot_path + '.svg')
        plot_url = '/' + os.path.join('pyplots', plot_path + '.svg').replace(os.sep, '/')

        figures = [manager.canvas.figure for manager in matplotlib._pylab_helpers.Gcf.get_all_fig_managers()]
        for figure in figures:
            makedirs(os.path.dirname(out_path))
            figure.savefig(out_path, format='svg')  # Yes, if there's more than one, it's overwritten, sucks.
        self.arguments = [plot_url]
        return super(PyPlot, self).run()