Merge branch '204-fix-stopiteration-error' into 'develop'

Resolve "Fix StopIteration error"

Closes #204

See merge request bramw/baserow!124

backend/src/baserow/contrib/database/api/fields/errors.py

@@ -30,3 +30,8 @@ ERROR_ORDER_BY_FIELD_NOT_POSSIBLE = (
     'It is not possible to order by {e.field_name} because the field type '
     '{e.field_type} does not support filtering.'
 )
+ERROR_INCOMPATIBLE_PRIMARY_FIELD_TYPE = (
+    'ERROR_INCOMPATIBLE_PRIMARY_FIELD_TYPE',
+    HTTP_400_BAD_REQUEST,
+    'The field type {e.field_type} is not compatible with the primary field.'
+)

backend/src/baserow/contrib/database/fields/exceptions.py

@@ -59,3 +59,11 @@ class OrderByFieldNotPossible(Exception):
         self.field_name = field_name
         self.field_type = field_type
         super().__init__(*args, **kwargs)
+
+
+class IncompatiblePrimaryFieldTypeError(Exception):
+    """Raised when the primary field is changed to an incompatible field type."""
+
+    def __init__(self, field_type=None, *args, **kwargs):
+        self.field_type = field_type
+        super().__init__(*args, **kwargs)

backend/src/baserow/contrib/database/fields/field_types.py

@@ -19,7 +19,8 @@ from baserow.contrib.database.api.fields.serializers import (
     LinkRowValueSerializer, FileFieldRequestSerializer, FileFieldResponseSerializer
 )
 from baserow.contrib.database.api.fields.errors import (
-    ERROR_LINK_ROW_TABLE_NOT_IN_SAME_DATABASE, ERROR_LINK_ROW_TABLE_NOT_PROVIDED
+    ERROR_LINK_ROW_TABLE_NOT_IN_SAME_DATABASE, ERROR_LINK_ROW_TABLE_NOT_PROVIDED,
+    ERROR_INCOMPATIBLE_PRIMARY_FIELD_TYPE
 )
 
 from .handler import FieldHandler
@@ -28,7 +29,10 @@ from .models import (
     NUMBER_TYPE_INTEGER, NUMBER_TYPE_DECIMAL, TextField, LongTextField, URLField,
     NumberField, BooleanField, DateField, LinkRowField, EmailField, FileField
 )
-from .exceptions import LinkRowTableNotInSameDatabase, LinkRowTableNotProvided
+from .exceptions import (
+    LinkRowTableNotInSameDatabase, LinkRowTableNotProvided,
+    IncompatiblePrimaryFieldTypeError
+)
 
 
 class TextFieldType(FieldType):
@@ -292,9 +296,11 @@ class LinkRowFieldType(FieldType):
     }
     api_exceptions_map = {
         LinkRowTableNotProvided: ERROR_LINK_ROW_TABLE_NOT_PROVIDED,
-        LinkRowTableNotInSameDatabase: ERROR_LINK_ROW_TABLE_NOT_IN_SAME_DATABASE
+        LinkRowTableNotInSameDatabase: ERROR_LINK_ROW_TABLE_NOT_IN_SAME_DATABASE,
+        IncompatiblePrimaryFieldTypeError: ERROR_INCOMPATIBLE_PRIMARY_FIELD_TYPE
     }
     can_order_by = False
+    can_be_primary_field = False
 
     def enhance_queryset(self, queryset, field, name):
         """

backend/src/baserow/contrib/database/fields/handler.py

@@ -12,7 +12,7 @@ from baserow.contrib.database.views.handler import ViewHandler
 
 from .exceptions import (
     PrimaryFieldAlreadyExists, CannotDeletePrimaryField, CannotChangeFieldType,
-    FieldDoesNotExist
+    FieldDoesNotExist, IncompatiblePrimaryFieldTypeError
 )
 from .registries import field_type_registry, field_converter_registry
 from .models import Field
@@ -168,6 +168,10 @@ class FieldHandler:
         # to remove all view filters.
         if new_type_name and field_type.type != new_type_name:
             field_type = field_type_registry.get(new_type_name)
+
+            if field.primary and not field_type.can_be_primary_field:
+                raise IncompatiblePrimaryFieldTypeError(new_type_name)
+
             new_model_class = field_type.model_class
             field.change_polymorphic_type_to(new_model_class)
 

backend/src/baserow/contrib/database/fields/registries.py

@@ -39,6 +39,9 @@ class FieldType(MapAPIExceptionsInstanceMixin, APIUrlsInstanceMixin,
     can_order_by = True
     """Indicates whether it is possible to order by this field type."""
 
+    can_be_primary_field = True
+    """Some field types cannot be the primary field."""
+
     def prepare_value_for_db(self, instance, value):
         """
         When a row is created or updated all the values are going to be prepared for the

backend/src/baserow/contrib/database/migrations/0020_fix_primary_link_row.py

@@ -0,0 +1,76 @@
+# Generated by Django 2.2.11 on 2020-11-16 08:53
+
+from django.db import migrations, connections
+from django.db.models import Exists, OuterRef, Q
+from django.conf import settings
+
+from baserow.contrib.database.table.models import Table as TableModel
+from baserow.contrib.database.fields.models import Field as FieldModel
+
+
+def forward(apps, schema_editor):
+    """
+    This migration fixes the not allowed situations where link row fields are primary
+    fields or if a table doesn't have a primary field anymore (because it was
+    deleted by the related link row field). In both cases a new primary text field is
+    created because that is allowed.
+    """
+
+    Table = apps.get_model('database', 'Table')
+    Field = apps.get_model('database', 'Field')
+    LinkRowField = apps.get_model('database', 'LinkRowField')
+    TextField = apps.get_model('database', 'TextField')
+    ContentType = apps.get_model('contenttypes', 'ContentType')
+    text_field_content_type = ContentType.objects.get_for_model(TextField)
+
+    # Check if there are tables without a primary field or where the primary field is
+    # a link row field, which is not allowed.
+    tables_without_primary = Table.objects.annotate(
+        has_primary=Exists(Field.objects.filter(table=OuterRef('pk'), primary=True)),
+        has_link_row_primary=Exists(
+            LinkRowField.objects.filter(table=OuterRef('pk'), primary=True)
+        )
+    ).filter(Q(has_primary=False) | Q(has_link_row_primary=True))
+    for table in tables_without_primary:
+        # If the table has a link row field as primary field it needs to be marked as
+        # normal field because they are not allowed to be primary.
+        if table.has_link_row_primary:
+            link_row_primary = LinkRowField.objects.get(table=table, primary=True)
+            link_row_primary.primary = False
+            link_row_primary.save()
+
+        # It might be possible in the future that the get_model or db_column methods
+        # are going to disappear. If that is the case then the creation of the field
+        # cannot be executed, so we can skip that.
+        if (
+            not hasattr(TableModel, 'get_model') or
+            not hasattr(FieldModel, 'db_column')
+        ):
+            continue
+
+        # We now know for sure there isn't a primary field in the table, so we can
+        # create a new primary text field because the table expects one.
+        new_primary = TextField.objects.create(
+            table=table,
+            name='Primary (auto created)',
+            order=0,
+            content_type=text_field_content_type,
+            primary=True
+        )
+        connection = connections[settings.USER_TABLE_DATABASE]
+        with connection.schema_editor() as tables_schema_editor:
+            to_model = TableModel.get_model(table, field_ids=[new_primary.id])
+            field_name = FieldModel.db_column.__get__(new_primary, FieldModel)
+            model_field = to_model._meta.get_field(field_name)
+            tables_schema_editor.add_field(to_model, model_field)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('database', '0019_filefield'),
+    ]
+
+    operations = [
+        migrations.RunPython(forward, migrations.RunPython.noop),
+    ]

backend/tests/baserow/contrib/database/api/fields/test_field_views.py

@@ -168,7 +168,7 @@ def test_update_field(api_client, data_fixture):
     user_2, token_2 = data_fixture.create_user_and_token()
     table = data_fixture.create_database_table(user=user)
     table_2 = data_fixture.create_database_table(user=user_2)
-    text = data_fixture.create_text_field(table=table)
+    text = data_fixture.create_text_field(table=table, primary=True)
     text_2 = data_fixture.create_text_field(table=table_2)
 
     url = reverse('api:database:fields:item', kwargs={'field_id': text_2.id})
@@ -192,6 +192,22 @@ def test_update_field(api_client, data_fixture):
     assert response.status_code == HTTP_404_NOT_FOUND
     assert response.json()['error'] == 'ERROR_FIELD_DOES_NOT_EXIST'
 
+    # The primary field is not compatible with a link row field so that should result
+    # in an error.
+    url = reverse('api:database:fields:item', kwargs={'field_id': text.id})
+    response = api_client.patch(
+        url,
+        {'type': 'link_row'},
+        format='json',
+        HTTP_AUTHORIZATION=f'JWT {token}'
+    )
+    assert response.status_code == HTTP_400_BAD_REQUEST
+    assert response.json()['error'] == 'ERROR_INCOMPATIBLE_PRIMARY_FIELD_TYPE'
+    assert (
+        response.json()['detail'] ==
+        'The field type link_row is not compatible with the primary field.'
+    )
+
     url = reverse('api:database:fields:item', kwargs={'field_id': text.id})
     response = api_client.patch(
         url,

backend/tests/baserow/contrib/database/field/test_field_handler.py

@@ -8,7 +8,7 @@ from baserow.contrib.database.fields.models import (
 )
 from baserow.contrib.database.fields.exceptions import (
     FieldTypeDoesNotExist, PrimaryFieldAlreadyExists, CannotDeletePrimaryField,
-    FieldDoesNotExist
+    FieldDoesNotExist, IncompatiblePrimaryFieldTypeError
 )
 
 
@@ -165,6 +165,15 @@ def test_update_field(data_fixture):
     with pytest.raises(FieldTypeDoesNotExist):
         handler.update_field(user=user, field=field, new_type_name='NOT_EXISTING')
 
+    # The link row field is not compatible with a primary field so an exception
+    # is expected.
+    field.primary = True
+    field.save()
+    with pytest.raises(IncompatiblePrimaryFieldTypeError):
+        handler.update_field(user=user, field=field, new_type_name='link_row')
+    field.primary = False
+    field.save()
+
     # Change some values of the text field and test if they have been changed.
     field = handler.update_field(user=user, field=field, name='Text field',
                                  text_default='Default value')

changelog.md

@@ -11,6 +11,8 @@
 * Set un-secure lax cookie when public web frontend url isn't over a secure connection.
 * Fixed bug where the sort choose field item didn't have a hover effect.
 * Implemented a file field and user files upload.
+* Made it impossible for the `link_row` field to be a primary field because that can
+  cause the primary field to be deleted.
 
 ## Released (2020-11-02)
 

web-frontend/modules/database/components/field/FieldForm.vue

@@ -29,6 +29,7 @@
             :icon="fieldType.iconClass"
             :name="fieldType.name"
             :value="fieldType.type"
+            :disabled="primary && !fieldType.canBePrimaryField"
           ></DropdownItem>
         </Dropdown>
         <div v-if="$v.values.type.$error" class="error">
@@ -62,6 +63,11 @@ export default {
       type: Object,
       required: true,
     },
+    primary: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
   },
   data() {
     return {

web-frontend/modules/database/components/field/UpdateFieldContext.vue

@@ -4,6 +4,7 @@
       ref="form"
       :table="table"
       :default-values="field"
+      :primary="field.primary"
       @submitted="submit"
     >
       <div class="context__form-actions">

web-frontend/modules/database/fieldTypes.js

@@ -96,6 +96,13 @@ export class FieldType extends Registerable {
     return true
   }
 
+  /**
+   * Indicates if is possible for the field type to be the primary field.
+   */
+  getCanBePrimaryField() {
+    return true
+  }
+
   constructor() {
     super()
     this.type = this.getType()
@@ -103,6 +110,7 @@ export class FieldType extends Registerable {
     this.name = this.getName()
     this.sortIndicator = this.getSortIndicator()
     this.canSortInView = this.getCanSortInView()
+    this.canBePrimaryField = this.getCanBePrimaryField()
 
     if (this.type === null) {
       throw new Error('The type name of a view type must be set.')
@@ -364,6 +372,10 @@ export class LinkRowFieldType extends FieldType {
     return false
   }
 
+  getCanBePrimaryField() {
+    return false
+  }
+
   prepareValueForCopy(field, value) {
     return JSON.stringify({
       tableId: field.link_row_table,