Patch Sphinx Include to support substitutions

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

docs/conf.py

@@ -13,7 +13,13 @@ from __future__ import unicode_literals
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import os
+import inspect
+import sys
+
+from docutils.parsers.rst import directives
+import docutils.parsers.rst.directives.misc
+from sphinx.directives.other import Include as SphinxInclude
 
 sys.path.insert(0, os.path.abspath('..'))
 
@@ -258,26 +264,55 @@ extlinks = {
 
 
 def _load_env_file(filename='../config.env'):
-    print('Loading env file: {}'.format(filename))
     result = []
     with open(filename) as file_object:
         for line in file_object:
             if not line.startswith('#'):
-                print('Found entry: {}'.format(line))
                 key, value = line.strip().split('=')
                 result.append(('|{}|'.format(key), value))
 
     return result
 
 
-def GlobalSubstitution(app, docname, source):
-    for old, new in global_subtitutions:
+def global_substitution_function(app, docname, source):
+    for old, new in global_subtitutions_list:
         source[0] = source[0].replace(old, new)
 
 
+def monkey_path_include():
+    """
+    Monkey path docutil's Include directive to support global substitutions.
+    The Include class doesn't have a hook to modify the content before
+    inserting it back, so we add a call to our own transformation
+    method. We patch the base Include class, recreate Sphinx's Include class,
+    and register it as the new main include directive.
+    All this avoids copy and paste of the original code here.
+    """
+    source_code = ''.join(inspect.getsourcelines(
+        docutils.parsers.rst.directives.misc.Include)[0]
+    )
+    source_code = source_code.replace(
+        'self.state_machine.insert_input(include_lines, path)',
+        'include_lines=self.global_substitution(lines=include_lines)\n        self.state_machine.insert_input(include_lines, path)',
+    )
+    exec(source_code, docutils.parsers.rst.directives.misc.__dict__)
+
+    class Include(docutils.parsers.rst.directives.misc.Include, SphinxInclude):
+        def global_substitution(self, lines):
+            result = []
+            for line in lines:
+                for old, new in global_subtitutions_list:
+                    line = line.replace(old, new)
+                result.append(line)
+            return result
+
+    return Include
+
+
 def setup(app):
     app.add_stylesheet('css/custom.css')
-    app.connect('source-read', GlobalSubstitution)
+    app.connect('source-read', global_substitution_function)
+    directives.register_directive('include', monkey_path_include())
 
 
-global_subtitutions = _load_env_file()
+global_subtitutions_list = _load_env_file()