Update converter to use app registry and deferred imports

apps/converter/__init__.py

@@ -2,4 +2,7 @@ from __future__ import absolute_import
 
 from navigation.api import register_sidebar_template
 
+from .exceptions import (UnknownFileFormat, IdentifyError, UnkownConvertError,
+    OfficeConversionError, OfficeBackendError)
+
 register_sidebar_template(['formats_list'], 'converter_file_formats_help.html')

apps/converter/api.py

@@ -12,7 +12,6 @@ from mimetype.api import get_mimetype
 
 from .literals import (DEFAULT_PAGE_NUMBER,
     DEFAULT_ZOOM_LEVEL, DEFAULT_ROTATION, DEFAULT_FILE_FORMAT)
-from .runtime import backend
 from .literals import (TRANSFORMATION_CHOICES, TRANSFORMATION_RESIZE,
     TRANSFORMATION_ROTATE, TRANSFORMATION_ZOOM, DIMENSION_SEPARATOR,
     FILE_FORMATS)
@@ -43,6 +42,8 @@ def create_image_cache_filename(input_filepath, *args, **kwargs):
 
 
 def convert(input_filepath, output_filepath=None, cleanup_files=False, mimetype=None, *args, **kwargs):
+    from .runtime import backend
+
     size = kwargs.get('size')
     file_format = kwargs.get('file_format', DEFAULT_FILE_FORMAT)
     zoom = kwargs.get('zoom', DEFAULT_ZOOM_LEVEL)
@@ -121,6 +122,8 @@ def convert(input_filepath, output_filepath=None, cleanup_files=False, mimetype=
 
 
 def get_page_count(input_filepath):
+    from .runtime import backend
+
     # Try to determine the page count first with the TextParser
     with open(input_filepath, 'rb') as descriptor:
         mimetype, encoding = get_mimetype(descriptor, input_filepath, mimetype_only=True)

apps/converter/office_converter.py

@@ -7,7 +7,6 @@ import logging
 from mimetype.api import get_mimetype
 from common.settings import TEMPORARY_DIRECTORY
 
-from .settings import LIBREOFFICE_PATH
 from .exceptions import OfficeBackendError, UnknownFileFormat
 
 CACHED_FILE_SUFFIX = u'_office_converter'
@@ -79,7 +78,9 @@ class OfficeConverter(object):
 
 class OfficeConverterBackendDirect(object):
     def __init__(self):
-        self.libreoffice_path = LIBREOFFICE_PATH if LIBREOFFICE_PATH else u'/usr/bin/libreoffice'
+        from .settings import LIBREOFFICE_PATH
+
+        self.libreoffice_path = LIBREOFFICE_PATH
         if not os.path.exists(self.libreoffice_path):
             raise OfficeBackendError('cannot find LibreOffice executable')
         logger.debug('self.libreoffice_path: %s' % self.libreoffice_path)