TG-35 : Structure TU + TU LoginAPI

backend/app/utils.py

@@ -2,6 +2,9 @@ import random
 import string
 from hashlib import sha512
 
+from flask import json
+from sqlalchemy.ext.declarative import DeclarativeMeta
+
 SIMPLE_CHARS = string.ascii_letters + string.digits
 
 
@@ -13,3 +16,38 @@ def get_random_hash(length=64):
     hash = sha512()
     hash.update(get_random_string())
     return hash.hexdigest()[:length]
+
+
+def new_alchemy_encoder(revisit_self=False, fields_to_expand=[]):
+    _visited_objs = []
+
+    class AlchemyEncoder(json.JSONEncoder):
+        def default(self, obj):
+            if isinstance(obj.__class__, DeclarativeMeta):
+                # don't re-visit self
+                if revisit_self:
+                    if obj in _visited_objs:
+                        return None
+                    _visited_objs.append(obj)
+
+                # go through each field in this SQLalchemy class
+                fields = {}
+                for field in [x for x in dir(obj) if not x.startswith('_') and x != 'metadata']:
+                    val = obj.__getattribute__(field)
+
+                    # is this field another SQLalchemy object, or a list of SQLalchemy objects?
+                    if isinstance(val.__class__, DeclarativeMeta) or (
+                            isinstance(val, list) and len(val) > 0 and isinstance(val[0].__class__, DeclarativeMeta)):
+                        # unless we're expanding this field, stop here
+                        if field not in fields_to_expand:
+                            # not expanding this field: set it to None and continue
+                            fields[field] = None
+                            continue
+
+                    fields[field] = val
+                # a json-encodable dict
+                return fields
+
+            return json.JSONEncoder.default(self, obj)
+
+    return AlchemyEncoder