Refactor template system to be easily extensible and voila compatible

.travis.yml

@@ -37,7 +37,7 @@ install:
     - pip install check-manifest
     - python -m ipykernel.kernelspec --user
 script:
-    - check-manifest
+    - check-manifest --ignore "share/**"
     # cd so we test the install, not the repo
     - cd `mktemp -d`
     - py.test --cov nbconvert -v --pyargs nbconvert

nbconvert/exporters/asciidoc.py

@@ -18,8 +18,8 @@ class ASCIIDocExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.asciidoc'
 
-    @default('template_file')
-    def _template_file_default(self):
+    @default('template_name')
+    def _template_name_default(self):
         return 'asciidoc'
 
     output_mimetype = 'text/asciidoc'

nbconvert/exporters/exporter.py

@@ -52,7 +52,7 @@ class Exporter(LoggingConfigurable):
     accompanying resources dict.
     """
 
-    file_extension = FilenameExtension('.txt',
+    file_extension = FilenameExtension(
         help="Extension of the file that should be written to disk"
     ).tag(config=True)
 

nbconvert/exporters/html.py

@@ -5,11 +5,15 @@
 # Distributed under the terms of the Modified BSD License.
 
 import os
+import mimetypes
+import base64
 
 from traitlets import default, Unicode
 from traitlets.config import Config
 from jupyter_core.paths import jupyter_path
 from jinja2 import contextfilter
+from jinja2.loaders import split_template_path
+import jinja2
 
 from nbconvert.filters.highlight import Highlight2HTML
 from nbconvert.filters.markdown_mistune import IPythonRenderer, MarkdownWithMath
@@ -33,17 +37,18 @@ class HTMLExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.html'
 
-    @default('default_template_path')
-    def _default_template_path_default(self):
-        return os.path.join("..", "templates", "html")
+    @default('template_name')
+    def _template_name_default(self):
+        return 'classic'
 
     @default('template_data_paths')
     def _template_data_paths_default(self):
         return jupyter_path("nbconvert", "templates", "html")
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'full.tpl'
+
+    theme = Unicode('light',
+                    help='Template specific theme(e.g. the JupyterLab CSS theme for the lab template)'
+    ).tag(config=True)
 
     output_mimetype = 'text/html'
 
@@ -93,3 +98,46 @@ def from_notebook_node(self, nb, resources=None, **kw):
         highlight_code = self.filters.get('highlight_code', Highlight2HTML(pygments_lexer=lexer, parent=self))
         self.register_filter('highlight_code', highlight_code)
         return super(HTMLExporter, self).from_notebook_node(nb, resources, **kw)
+
+    def _init_resources(self, resources):
+        def resources_include_css(name):
+            env = self.environment
+            code = """<style type="text/css">\n%s</style>""" % (env.loader.get_source(env, name)[0])
+            return jinja2.Markup(code)
+
+        def resources_include_js(name):
+            env = self.environment
+            code = """<script>\n%s</script>""" % (env.loader.get_source(env, name)[0])
+            return jinja2.Markup(code)
+
+        def resources_include_url(name):
+            env = self.environment
+            mime_type, encoding = mimetypes.guess_type(name)
+            try:
+                # we try to load via the jinja loader, but that tries to load
+                # as (encoded) text
+                data = env.loader.get_source(env, name)[0].encode('utf8')
+            except UnicodeDecodeError:
+                # if that fails (for instance a binary file, png or ttf)
+                # we mimic jinja2
+                pieces = split_template_path(name)
+                searchpaths = self.get_template_paths()
+                for searchpath in searchpaths:
+                    filename = os.path.join(searchpath, *pieces)
+                    print(filename, os.path.exists(filename))
+                    if os.path.exists(filename):
+                        with open(filename, "rb") as f:
+                            data = f.read()
+                            break
+                else:
+                    raise ValueError("No file %r found in %r" % (name, searchpaths))
+            data = base64.b64encode(data)
+            data = data.replace(b'\n', b'').decode('ascii')
+            src = 'data:{mime_type};base64,{data}'.format(mime_type=mime_type, data=data)
+            return jinja2.Markup(src)
+        resources = super(HTMLExporter, self)._init_resources(resources)
+        resources['theme'] = self.theme
+        resources['include_css'] = resources_include_css
+        resources['include_js'] = resources_include_js
+        resources['include_url'] = resources_include_url
+        return resources

nbconvert/exporters/latex.py

@@ -27,25 +27,14 @@ class LatexExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.tex'
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'article.tplx'
-
-    # Latex constants
-    @default('default_template_path')
-    def _default_template_path_default(self):
-        return os.path.join("..", "templates", "latex")
-
-    @default('template_skeleton_path')
-    def _template_skeleton_path_default(self):
-        return os.path.join("..", "templates", "latex", "skeleton")
 
     @default('template_data_paths')
     def _template_data_paths_default(self):
         return jupyter_path("nbconvert", "templates", "latex")
-
-    #Extension that the template files use.
-    template_extension = Unicode(".tplx").tag(config=True)
+
+    @default('template_name')
+    def _template_name_default(self):
+        return 'latex'
 
     output_mimetype = 'text/latex'
 

nbconvert/exporters/markdown.py

@@ -19,9 +19,9 @@ class MarkdownExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.md'
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'markdown.tpl'
+    @default('template_name')
+    def _template_name_default(self):
+        return 'markdown'
 
     output_mimetype = 'text/markdown'
 

nbconvert/exporters/pdf.py

@@ -73,6 +73,11 @@ class PDFExporter(LatexExporter):
     def _file_extension_default(self):
         return '.pdf'
 
+
+    @default('template_extension')
+    def _template_extension_default(self):
+        return '.tex.j2'
+
     def run_command(self, command_list, filename, count, log_function, raise_on_failure=None):
         """Run command_list count times.
 

nbconvert/exporters/python.py

@@ -16,8 +16,8 @@ class PythonExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.py'
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'python.tpl'
+    @default('template_name')
+    def _template_name_default(self):
+        return 'python'
 
     output_mimetype = 'text/x-python'

nbconvert/exporters/rst.py

@@ -18,9 +18,9 @@ class RSTExporter(TemplateExporter):
     def _file_extension_default(self):
         return '.rst'
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'rst.tpl'
+    @default('template_name')
+    def _template_name_default(self):
+        return 'rst'
 
     output_mimetype = 'text/restructuredtext'
     export_from_notebook = "reST"

nbconvert/exporters/script.py

@@ -18,7 +18,11 @@ class ScriptExporter(TemplateExporter):
 
     @default('template_file')
     def _template_file_default(self):
-        return 'script.tpl'
+        return 'script.j2'
+
+    @default('template_name')
+    def _template_name_default(self):
+        return 'script'
 
     def _get_language_exporter(self, lang_name):
         """Find an exporter for the language name from notebook metadata.

nbconvert/exporters/slides.py

@@ -77,6 +77,14 @@ class SlidesExporter(HTMLExporter):
 
     export_from_notebook = "Reveal.js slides"
 
+    @default('template_name')
+    def _template_name_default(self):
+        return 'reveal'
+
+    template_name = Unicode('reveal',
+            help="Name of the template to use"
+    ).tag(config=True, affects_template=True)
+
     reveal_url_prefix = Unicode(
         help="""The URL prefix for reveal.js (version 3.x).
         This defaults to the reveal CDN, but can be any url pointing to a copy 
@@ -160,9 +168,9 @@ def _reveal_url_prefix_default(self):
     def _file_extension_default(self):
         return '.slides.html'
 
-    @default('template_file')
-    def _template_file_default(self):
-        return 'slides_reveal.tpl'
+    @default('template_extension')
+    def _template_extension_default(self):
+        return '.html.j2'
 
     output_mimetype = 'text/html'