A save hook for Jupyter that automatically exports notebooks as slides

jupyter_notebook_config.py

"""This is a save hook for Jupyter that automatically exports your notebook to reveal slides, 
every time you save it, if
- it has at least one cell with a "slideshow" metadata
- and if the notebook is not `Untitled...`

Add the following to your `.jupyter/jupyter_notebook_config.py` file:
(source: https://gist.github.com/mwouts/04a6dfa571bda5cc59fa1429d130998f )
"""

import io
import os
import nbformat
from nbconvert.exporters import SlidesExporter
from notebook.utils import to_api_path


def export_to_slides(model, path, contents_manager, **kwargs):
    """A pre-save hook that exports notebooks as slides if one of their cell has a "slideshow" metadata"""
    if model["type"] != "notebook":
        return

    nb = model['content']
    assert nb is not None, "Please call this function as a pre_save_hook"

    try:
        # Is this a paired notebook?
        from jupytext.paired_paths import paired_paths
        if path in contents_manager.paired_notebooks:
            fmt, formats = contents_manager.paired_notebooks.get(path)
            alt_paths = paired_paths(path, fmt, formats)

            # run the export only if this function is called on the first element of the pair
            if len(alt_paths) > 1 and path != alt_paths[0][0]:
                return

    except (AttributeError, ImportError):
        pass

    slideshow = False
    for cell in nb['cells']:
        if 'slideshow' in cell['metadata']:
            slideshow = True
            break

    if not slideshow:
        return

    log = contents_manager.log
    log.debug('Notebook %s has a slideshow cell metadata', path)

    os_path = contents_manager._get_os_path(path)
    if os.path.basename(os_path).startswith('Untitled'):
        log.info("Not exporting %s as slides because it's untitled", path)
        return

    exporter = SlidesExporter(parent=contents_manager)
    slides, resources = exporter.from_notebook_node(nbformat.from_dict(nb))

    base, __ = os.path.splitext(os_path)
    slides_fname = base + resources.get('output_extension', '.html')
    log.info("Saving slides at /%s", to_api_path(slides_fname, contents_manager.root_dir))

    with io.open(slides_fname, "w", encoding="utf-8") as f:
        f.write(slides)


c.FileContentsManager.pre_save_hook = export_to_slides