study.custom_heuristic changed to be non-nullable

Heuristic column should not be nullable. Refactored slightly to set
default to be whatever is stored under study.custom_heuristic, and
making the column non-nullable.

autobidsportal/forms.py

@@ -53,21 +53,6 @@ def get_default_bidsignore() -> str:
         return bidsignore_file.read()
 
 
-@lru_cache
-def get_default_heuristic() -> str:
-    """Read default heuristic file.
-
-    Returns
-    -------
-    str
-        Contents of heuristic
-    """
-    with (Path(__file__).parent / "resources" / "heuristics.py.default").open(
-        encoding="utf-8",
-    ) as heuristics_file:
-        return heuristics_file.read()
-
-
 def _gen_familiarity_field(label: str) -> SelectField:
     """Generate familiarty selections.
 
@@ -388,11 +373,7 @@ def defaults_from_study(
         if study.retrospective_data:
             self.retrospective_start.default = study.retrospective_start
             self.retrospective_end.default = study.retrospective_end
-        self.heuristic.default = (
-            get_default_heuristic()
-            if study.custom_heuristic is None
-            else study.custom_heuristic
-        )
+        self.heuristic.default = study.heuristic
         if study.subj_expr is None:
             self.subj_expr.default = "*_{subject}"
         else:
@@ -528,7 +509,7 @@ def update_study(
         study.principal = self.pi_name.data
         study.project_name = self.project_name.data
         study.dataset_name = self.dataset_name.data
-        study.custom_heuristic = self.heuristic.data
+        study.heuristic = self.heuristic.data
         study.subj_expr = self.subj_expr.data
         study.deface = self.deface.data
         study.patient_str = self.patient_str.data

autobidsportal/models.py

@@ -8,6 +8,8 @@
 from collections.abc import Sequence
 from datetime import datetime
 from enum import Enum
+from functools import lru_cache
+from pathlib import Path
 from time import time
 from typing import Any
 
@@ -22,6 +24,21 @@
 
 from autobidsportal.dateutils import TIME_ZONE
 
+
+@lru_cache
+def get_default_heuristic() -> str:
+    """Read default heuristic file.
+
+    Returns
+    -------
+    str
+        Contents of heuristic
+    """
+    with (Path(__file__).parent / "resources" / "heuristics.py.default").open(
+        encoding="utf-8",
+    ) as heuristics_file:
+        return heuristics_file.read()
+
 login = LoginManager()
 convention = {
     "ix": "ix_%(column_0_label)s",
@@ -393,7 +410,10 @@ class Study(db.Model):
 
     custom_bidsignore = db.Column(db.Text, nullable=True)
 
-    custom_heuristic = db.Column(db.Text, nullable=True)
+    # There should be a default here
+    heuristic = db.Column(
+        db.Text, nullable=False, default=get_default_heuristic(),
+    )
 
     def __repr__(self) -> str:
         """Generate a str representation of this study."""
@@ -478,7 +498,7 @@ class Tar2bidsOutput(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     study_id = db.Column(db.Integer, db.ForeignKey("study.id"), nullable=False)
     bids_dir = db.Column(db.String(200), index=True, nullable=True)
-    heuristic = db.Column(db.Text, index=True, nullable=True)
+    heuristic = db.Column(db.Text, index=True, nullable=False)
 
     def __repr__(self) -> str:
         """Generate a str representation of this output."""