fix(data): update field value in database

Update temporal_frequency field values in the database
following update to (forgotten) single TemporalFrequency
TextChoices value in models.py to fix potential data
divergence.

apis_ontology/migrations/0087_data_migration_fix_textchoices_value.py

@@ -0,0 +1,113 @@
+"""
+Data migration to update DB values of `Work` entity`temporal_frequency` field
+following the discovery that one `TextChoices` value was not updated
+from English to German in models.py.
+
+Reuses migration 0084's most pared down value conversion approach so far.
+"""
+
+# Generated by Django 4.2.15 on 2024-09-19 08:07
+
+import logging
+from functools import partial
+
+from django.db import migrations
+
+
+logger = logging.getLogger(__name__)
+
+# list of dicts containing old and new field (string) values
+TEMPORAL_FREQUENCY_VALUES = [  #  TemporalFrequency in models
+    {
+        "old": "singulative",
+        "new": "singulativ",
+    },
+]
+
+# list of dicts linking fields with field value dicts and models they appear in
+UPDATE_FIELDS = [
+    {
+        "models": ["Work", "VersionWork"],
+        "fields": [
+            {
+                "name": "temporal_frequency",
+                "values": TEMPORAL_FREQUENCY_VALUES,
+            },
+        ],
+    },
+]
+
+
+def update_field_values(apps, schema_editor, from_key="old", to_key="new"):
+    """
+    Replace existing field values in the database with new values if
+    they match a given string.
+
+    Assumes affected fields contain strings (CharField, TextField,...)
+    or a list of strings (PostgreSQL ArrayField with a string field for
+    base_field).
+
+    :param from_key: identifier for current value in field value dict
+    :type from_key: str
+    :param to_key: identifier for replacement value in field value dict
+    :type to_key: str
+    """
+
+    for item in UPDATE_FIELDS:
+        for model in item["models"]:
+            model_class = apps.get_model("apis_ontology", model)
+
+            for obj in model_class.objects.all():
+                for field in item["fields"]:
+                    field_name = field["name"]
+                    field_values = field["values"]
+
+                    field_data = getattr(obj, field_name, None)
+
+                    if field_data:
+                        converted_data = field_data
+
+                        if isinstance(field_data, str):
+                            for c in field_values:
+                                if field_data == c[from_key]:
+                                    converted_data = c[to_key]
+
+                        if isinstance(field_data, list):
+                            converted_data = []
+                            for value in field_data:
+                                for c in field_values:
+                                    if value == c[from_key]:
+                                        value = c[to_key]
+                                converted_data.append(value)
+
+                        if converted_data != field_data:
+                            setattr(obj, field_name, converted_data)
+
+                            # log value conversions
+                            logger.info(
+                                f"Converted: {','.join(field_data) if isinstance(field_data, list) else field_data} "
+                                f"-> {','.join(converted_data) if isinstance(converted_data, list) else converted_data} "
+                                f"({model}, ID: {getattr(obj, 'id', [])})"
+                            )
+
+                            if hasattr(obj, "skip_history_when_saving"):
+                                obj.skip_history_when_saving = True
+
+                            obj.save()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("apis_ontology", "0086_alter_versionwork_temporal_frequency_and_more"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            code=update_field_values,
+            reverse_code=partial(
+                update_field_values,
+                from_key="new",
+                to_key="old",
+            ),
+        ),
+    ]