[collapsible_headings] simplify embedding js into main html page

by detecting whether we're in a live notebook, then defining
with/without an explicit module name as appropriate

Author: jcb91

src/jupyter_contrib_nbextensions/nbconvert_support/collapsible_headings.py

@@ -32,8 +32,7 @@ def __init__(self, *args, **kwargs):
             'collapsible_headings')
 
         with open(os.path.join(ch_dir, 'main.css'), 'r') as f:
-            main_css = f.read()
-        self.inliner_resources['css'].append(main_css)
+            self.inliner_resources['css'].append(f.read())
 
         self.inliner_resources['css'].append("""
 /* no local copies of fontawesome fonts from basic templates, so get them from cdn */
@@ -50,11 +49,7 @@ def __init__(self, *args, **kwargs):
 """)  # noqa: E501
 
         with open(os.path.join(ch_dir, 'main.js'), 'r') as f:
-            self.inliner_resources['js'].append(
-                f.read().replace(
-                    "define([",
-                    "define('nbextensions/collapsible_headings/main', [")
-            )
+            self.inliner_resources['js'].append(f.read())
 
         cm = ConfigManager()
         collapsible_headings_options = cm.get('notebook').get(

src/jupyter_contrib_nbextensions/nbextensions/collapsible_headings/main.js

@@ -1,4 +1,9 @@
-define(['jquery', 'require'], function ($, require) {
+(require.specified('base/js/namespace') ? define : function (deps, callback) {
+	// if here, the Jupyter namespace hasn't been specified to be loaded.
+	// This means that we're probably embedded in a page, so we need to make
+	// our definition with a specific module name
+	return define('nbextensions/collapsible_headings/main', deps, callback);
+})(['jquery', 'require'], function ($, require) {
 	"use strict";
 
 	var mod_name = 'collapsible_headings';
@@ -632,7 +637,7 @@ define(['jquery', 'require'], function ($, require) {
 					var filter_func;
 					if (is_h) {
 						var lvl = get_cell_level(cell);
-						filter_func = function (c) { return get_cell_level(c) < lvl; }
+						filter_func = function (c) { return get_cell_level(c) < lvl; };
 					}
 					cell = find_header_cell(cell, filter_func);
 					if (cell !== undefined) {
@@ -1025,7 +1030,7 @@ define(['jquery', 'require'], function ($, require) {
 			add_buttons_and_shortcuts();
 		})
 		.catch(function on_reject (reason) {
-			console.error(log_prefix, 'error:', reason)
+			console.error(log_prefix, 'error:', reason);
 		});
 	}