Improve DataObjFormatters Handling for New Tables

specifyweb/context/app_resource.py

@@ -58,6 +58,42 @@ def get_app_resource(collection, user, resource_name, additional_default=False):
     logger.info('looking for app resource %r for user %s in %s',
                 resource_name, user and user.name, collection and collection.collectionname)
 
+    # Handling for DataObjFormatters to support fallback to defaults
+    if resource_name == 'DataObjFormatters':
+        custom_formatter = None
+        default_formatter = None
+
+        # Try to search for the the custom formatter first
+        for level in DIR_LEVELS:
+            # First look in the database.
+            from_db = get_app_resource_from_db(collection, user, level, resource_name)
+            if from_db is not None:
+                custom_formatter = from_db
+                break
+
+            # If resource was not found, look on the filesystem.
+            from_fs = load_resource_at_level(collection, user, level, resource_name)
+            if from_fs is not None:
+                custom_formatter = from_fs
+                break
+
+        # If custom formatter not found, try to load the default formatter from the backstop level
+        default_formatter = load_resource_at_level(collection, user, 'Backstop', resource_name)
+
+        # If both custom and default formatters are found, merge them
+        if custom_formatter is not None and default_formatter is not None:
+            merged_formatter = merge_formatters(custom_formatter[0], default_formatter[0])
+            return merged_formatter, custom_formatter[1], custom_formatter[2]
+
+        # Return the custom formatter if it exists, otherwise return the default
+        if custom_formatter is not None:
+            return custom_formatter
+
+        if default_formatter is not None:
+            return default_formatter
+
+        return None
+
     if not additional_default:
         # Traverse the hierarchy.
         for level in DIR_LEVELS:
@@ -202,3 +238,29 @@ def get_app_resource_dirs_for_level(collection, user, level):
 
     # Build the queryset.
     return Spappresourcedir.objects.filter(**filters)
+
+def merge_formatters(custom_xml, default_xml):
+    """Merge custom and default XML formatters.
+    This function takes two XML strings, one for custom formatters and one for default formatters,
+    and merges them by adding any formatters from the default XML that are not already present in
+    the custom XML. It returns the merged XML as a string.
+    """
+
+    custom_root = ElementTree.fromstring(custom_xml)
+    default_root = ElementTree.fromstring(default_xml)
+
+    # Create a set of existing classes in the custom XML to avoid duplicates
+    custom_classes = set()
+    for format_elem in custom_root.findall('format'):
+        class_attr = format_elem.get('class')
+        if class_attr:
+            custom_classes.add(class_attr)
+
+    # Add formatters from default that don't exist in custom
+    for format_elem in default_root.findall('format'):
+        class_attr = format_elem.get('class')
+        if class_attr and class_attr not in custom_classes:
+            custom_root.append(format_elem)
+
+    # Convert the merged XML tree back to a string
+    return ElementTree.tostring(custom_root, encoding='utf-8').decode('utf-8')