Add helper to map API field name to DB column

Author: harminius

server/mergin/sync/public_api_v2_controller.py

@@ -49,7 +49,7 @@
 from .storages.disk import move_to_tmp, save_to_file
 from .utils import get_device_id, get_ip, get_user_agent, get_chunk_location
 from .workspace import WorkspaceRole
-from ..utils import parse_order_params
+from ..utils import parse_order_params, get_schema_fields_map
 
 
 @auth_required
@@ -437,7 +437,9 @@ def list_workspace_projects(workspace_id, page, per_page, order_params=None, q=N
         projects = projects.filter(Project.name.ilike(f"%{q}%"))
 
     if order_params:
-        order_by_params = parse_order_params(Project, order_params)
+        order_by_params = parse_order_params(
+            Project, order_params, field_map=ProjectSchemaV2.field_map
+        )
         projects = projects.order_by(*order_by_params)
 
     result = projects.paginate(page, per_page).items

server/mergin/sync/schemas_v2.py

@@ -11,6 +11,7 @@
     Project,
     ProjectVersion,
 )
+from ..utils import get_schema_fields_map
 
 
 class ProjectSchema(ma.SQLAlchemyAutoSchema):
@@ -46,3 +47,6 @@ class Meta:
             "workspace",
             "role",
         )
+
+
+ProjectSchema.field_map = get_schema_fields_map(ProjectSchema)

server/mergin/tests/test_public_api_v2.py

@@ -643,6 +643,13 @@ def test_list_workspace_projects(client):
         url + f"?page={page}&per_page={per_page}&q=1&order_params=created DESC"
     )
     assert response.json["projects"][0]["name"] == "project_10"
+    # using field name instead column names for sorting
+    p4 = Project.query.filter(Project.name == project_name).first()
+    p4.disk_usage = 1234567
+    db.session.commit()
+    response = client.get(url + f"?page=1&per_page=10&order_params=size DESC")
+    resp_data = json.loads(response.data)
+    assert resp_data["projects"][0]["name"] == project_name
 
     # no permissions to workspace
     user2 = add_user("user", "password")

server/mergin/utils.py

@@ -6,8 +6,9 @@
 from datetime import datetime, timedelta, timezone
 from enum import Enum
 import os
-from flask import current_app
+from flask import current_app, abort
 from flask_sqlalchemy import Model
+from marshmallow import Schema
 from pathvalidate import sanitize_filename
 from sqlalchemy import Column, JSON
 from sqlalchemy.sql.elements import UnaryExpression
@@ -33,7 +34,7 @@ def split_order_param(order_param: str) -> Optional[OrderParam]:
 
 
 def get_order_param(
-    cls: Model, order_param: OrderParam, json_sort: dict = None
+    cls: Model, order_param: OrderParam, json_sort: dict = None, field_map: dict = None
 ) -> Optional[UnaryExpression]:
     """Return order by clause parameter for SQL query
 
@@ -43,12 +44,18 @@ def get_order_param(
     :type order_param: OrderParam
     :param json_sort: type mapping for sort by json field, e.g. '{"storage": "int"}', defaults to None
     :type json_sort: dict
+    :param field_map: mapping for translating public field names to internal DB columns, e.g. '{"size": "disk_usage"}'
+    :type field_map: dict
     """
+    # translate field name to column name
+    db_column_name = order_param.name
+    if field_map and order_param.name in field_map:
+        db_column_name = field_map[order_param.name]
     # find candidate for nested json sort
-    if "." in order_param.name:
-        col, attr = order_param.name.split(".")
+    if "." in db_column_name:
+        col, attr = db_column_name.split(".")
     else:
-        col = order_param.name
+        col = db_column_name
         attr = None
     order_attr = cls.__table__.c.get(col, None)
     if not isinstance(order_attr, Column):
@@ -80,7 +87,9 @@ def get_order_param(
         return order_attr.desc()
 
 
-def parse_order_params(cls: Model, order_params: str, json_sort: dict = None):
+def parse_order_params(
+    cls: Model, order_params: str, json_sort: dict = None, field_map: dict = None
+) -> list[UnaryExpression]:
     """Convert order parameters in query string to list of order by clauses.
 
     :param cls: Db model class
@@ -89,6 +98,8 @@ def parse_order_params(cls: Model, order_params: str, json_sort: dict = None):
     :type order_params: str
     :param json_sort: type mapping for sort by json field, e.g. '{"storage": "int"}', defaults to None
     :type json_sort: dict
+    :param field_map: mapping response fields to database column names, e.g. '{"size": "disk_usage"}'
+    :type field_map: dict
 
     :rtype: List[Column]
     """
@@ -97,7 +108,7 @@ def parse_order_params(cls: Model, order_params: str, json_sort: dict = None):
         order_param = split_order_param(p)
         if not order_param:
             continue
-        order_attr = get_order_param(cls, order_param, json_sort)
+        order_attr = get_order_param(cls, order_param, json_sort, field_map)
         if order_attr is not None:
             order_by_params.append(order_attr)
     return order_by_params
@@ -135,3 +146,16 @@ def save_diagnostic_log_file(app: str, username: str, body: bytes) -> str:
         f.write(content)
 
     return file_name
+
+
+def get_schema_fields_map(schema: Schema) -> dict:
+    """
+    Creates a mapping of schema field names to corresponding DB columns.
+    This allows sorting by the API field name (e.g. 'size') while
+    actually sorting by the database column (e.g. 'disk_usage').
+    """
+    mapping = {}
+    for name, field in schema._declared_fields.items():
+        if field and field.attribute:
+            mapping[name] = field.attribute
+    return mapping