Refactor rest_api app and the method end points are registered. All apps API URL endpoints are now registered under the 'rest_api' namespace.

Update DRF and DRF swagger versions. Update all apps API registration method.

mayan/apps/documents/widgets.py

@@ -99,11 +99,12 @@ def document_html_widget(document_page, click_view=None, click_view_arguments=No
 
     alt_text = _('Document page image')
 
+    if not document_page:
+        return mark_safe('<span class="fa-stack fa-lg"><i class="fa fa-file-o fa-stack-2x"></i><i class="fa fa-question fa-stack-1x text-danger"></i></span>')
+
     document = document_page.document
-    page = document_page.page_number
 
     query_dict = {
-        'page': page,
         'zoom': zoom,
         'rotation': rotation,
         'size': size,
@@ -117,12 +118,12 @@ def document_html_widget(document_page, click_view=None, click_view_arguments=No
     query_string = urlencode(query_dict)
 
     preview_view = '%s?%s' % (
-        reverse('document-image', args=[document.pk]), query_string
+        reverse('rest_api:documentpage-image', args=[document_page.pk]), query_string
     )
 
     result.append(
         '<div class="tc" id="document-%d-%d">' % (
-            document.pk, page if page else 1
+            document.pk, document_page.page_number if document_page.page_number else 1
         )
     )