Simplify the various settings objects, to improve retrieval of 'parameters' from the base class

- Remove the GenericReferencedSettingsClass mixin
- Each subclass defines a very simple get_kwargs() method
- Now, at object level *and* class level we can perform lookup of settings and actually get proper data back
- Adds "model" option to setting (precursor of things to come)

InvenTree/common/models.py

@@ -136,6 +136,19 @@ class BaseInvenTreeSetting(models.Model):
 
         return settings
 
+    def get_kwargs(self):
+        """
+        Construct kwargs for doing class-based settings lookup,
+        depending on *which* class we are.
+
+        This is necessary to abtract the settings object
+        from the implementing class (e.g plugins)
+        
+        Subclasses should override this function to ensure the kwargs are correctly set.
+        """
+
+        return {}
+
     @classmethod
     def get_setting_definition(cls, key, **kwargs):
         """
@@ -319,11 +332,11 @@ class BaseInvenTreeSetting(models.Model):
             value = setting.value
 
             # Cast to boolean if necessary
-            if setting.is_bool(**kwargs):
+            if setting.is_bool():
                 value = InvenTree.helpers.str2bool(value)
 
             # Cast to integer if necessary
-            if setting.is_int(**kwargs):
+            if setting.is_int():
                 try:
                     value = int(value)
                 except (ValueError, TypeError):
@@ -390,19 +403,19 @@ class BaseInvenTreeSetting(models.Model):
 
     @property
     def name(self):
-        return self.__class__.get_setting_name(self.key)
+        return self.__class__.get_setting_name(self.key, **self.get_kwargs())
 
     @property
     def default_value(self):
-        return self.__class__.get_setting_default(self.key)
+        return self.__class__.get_setting_default(self.key, **self.get_kwargs())
 
     @property
     def description(self):
-        return self.__class__.get_setting_description(self.key)
+        return self.__class__.get_setting_description(self.key, **self.get_kwargs())
 
     @property
     def units(self):
-        return self.__class__.get_setting_units(self.key)
+        return self.__class__.get_setting_units(self.key, **self.get_kwargs())
 
     def clean(self, **kwargs):
         """
@@ -512,12 +525,12 @@ class BaseInvenTreeSetting(models.Model):
         except self.DoesNotExist:
             pass
 
-    def choices(self, **kwargs):
+    def choices(self):
         """
         Return the available choices for this setting (or None if no choices are defined)
         """
 
-        return self.__class__.get_setting_choices(self.key, **kwargs)
+        return self.__class__.get_setting_choices(self.key, **self.get_kwargs())
 
     def valid_options(self):
         """
@@ -531,14 +544,14 @@ class BaseInvenTreeSetting(models.Model):
 
         return [opt[0] for opt in choices]
 
-    def is_choice(self, **kwargs):
+    def is_choice(self):
         """
         Check if this setting is a "choice" field
         """
 
-        return self.__class__.get_setting_choices(self.key, **kwargs) is not None
+        return self.__class__.get_setting_choices(self.key, **self.get_kwargs()) is not None
 
-    def as_choice(self, **kwargs):
+    def as_choice(self):
         """
         Render this setting as the "display" value of a choice field,
         e.g. if the choices are:
@@ -547,7 +560,7 @@ class BaseInvenTreeSetting(models.Model):
         then display 'A4 paper'
         """
 
-        choices = self.get_setting_choices(self.key, **kwargs)
+        choices = self.get_setting_choices(self.key, **self.get_kwargs())
 
         if not choices:
             return self.value
@@ -558,12 +571,28 @@ class BaseInvenTreeSetting(models.Model):
 
         return self.value
 
-    def is_bool(self, **kwargs):
+    def is_model(self):
+        """
+        Check if this setting references a model instance in the database
+        """
+
+        return self.model_name() is not None
+
+    def model_name(self):
+        """
+        Return the model name associated with this setting
+        """
+
+        setting = self.get_setting_definition(self.key, **self.get_kwargs())
+
+        return setting.get('model', None)
+
+    def is_bool(self):
         """
         Check if this setting is required to be a boolean value
         """
 
-        validator = self.__class__.get_setting_validator(self.key, **kwargs)
+        validator = self.__class__.get_setting_validator(self.key, **self.get_kwargs())
 
         return self.__class__.validator_is_bool(validator)
 
@@ -576,17 +605,20 @@ class BaseInvenTreeSetting(models.Model):
 
         return InvenTree.helpers.str2bool(self.value)
 
-    def setting_type(self, **kwargs):
+    def setting_type(self):
         """
         Return the field type identifier for this setting object
         """
 
-        if self.is_bool(**kwargs):
+        if self.is_bool():
             return 'boolean'
 
-        elif self.is_int(**kwargs):
+        elif self.is_int():
             return 'integer'
 
+        elif self.is_model():
+            return 'model'
+
         else:
             return 'string'
 
@@ -603,12 +635,12 @@ class BaseInvenTreeSetting(models.Model):
 
         return False
 
-    def is_int(self, **kwargs):
+    def is_int(self,):
         """
         Check if the setting is required to be an integer value:
         """
 
-        validator = self.__class__.get_setting_validator(self.key, **kwargs)
+        validator = self.__class__.get_setting_validator(self.key, **self.get_kwargs())
 
         return self.__class__.validator_is_int(validator)
 
@@ -651,88 +683,7 @@ class BaseInvenTreeSetting(models.Model):
 
     @property
     def protected(self):
-        return self.__class__.is_protected(self.key)
+        return self.__class__.is_protected(self.key, **self.get_kwargs())
-
-
-class GenericReferencedSettingClass:
-    """
-    This mixin can be used to add reference keys to static properties
-
-    Sample:
-    ```python
-    class SampleSetting(GenericReferencedSettingClass, common.models.BaseInvenTreeSetting):
-        class Meta:
-            unique_together = [
-                ('sample', 'key'),
-            ]
-
-        REFERENCE_NAME = 'sample'
-
-        @classmethod
-        def get_setting_definition(cls, key, **kwargs):
-            # mysampledict contains the dict with all settings for this SettingClass - this could also be a dynamic lookup
-
-            kwargs['settings'] = mysampledict
-            return super().get_setting_definition(key, **kwargs)
-
-        sample = models.charKey(  # the name for this field is the additonal key and must be set in the Meta class an REFERENCE_NAME
-            max_length=256,
-            verbose_name=_('sample')
-        )
-    ```
-    """
-
-    REFERENCE_NAME = None
-
-    def _get_reference(self):
-        """
-        Returns dict that can be used as an argument for kwargs calls.
-        Helps to make overriden calls generic for simple reuse.
-
-        Usage:
-        ```python
-        some_random_function(argument0, kwarg1=value1, **self._get_reference())
-        ```
-        """
-        return {
-            self.REFERENCE_NAME: getattr(self, self.REFERENCE_NAME)
-        }
-
-    """
-    We override the following class methods,
-    so that we can pass the modified key instance as an additional argument
-    """
-
-    def clean(self, **kwargs):
-
-        kwargs[self.REFERENCE_NAME] = getattr(self, self.REFERENCE_NAME)
-
-        super().clean(**kwargs)
-
-    def is_bool(self, **kwargs):
-
-        kwargs[self.REFERENCE_NAME] = getattr(self, self.REFERENCE_NAME)
-
-        return super().is_bool(**kwargs)
-
-    @property
-    def name(self):
-        return self.__class__.get_setting_name(self.key, **self._get_reference())
-
-    @property
-    def default_value(self):
-        return self.__class__.get_setting_default(self.key, **self._get_reference())
-
-    @property
-    def description(self):
-        return self.__class__.get_setting_description(self.key, **self._get_reference())
-
-    @property
-    def units(self):
-        return self.__class__.get_setting_units(self.key, **self._get_reference())
-
-    def choices(self):
-        return self.__class__.get_setting_choices(self.key, **self._get_reference())
 
 
 def settings_group_options():
@@ -1558,6 +1509,16 @@ class InvenTreeUserSetting(BaseInvenTreeSetting):
 
         return self.__class__.get_setting(self.key, user=self.user)
 
+    def get_kwargs(self):
+        """
+        Explicit kwargs required to uniquely identify a particular setting object,
+        in addition to the 'key' parameter
+        """
+
+        return {
+            'user': self.user,
+        }
+
 
 class PriceBreak(models.Model):
     """

InvenTree/common/serializers.py

@@ -28,6 +28,8 @@ class SettingsSerializer(InvenTreeModelSerializer):
 
     choices = serializers.SerializerMethodField()
 
+    model_name = serializers.CharField(read_only=True)
+
     def get_choices(self, obj):
         """
         Returns the choices available for a given item
@@ -75,6 +77,7 @@ class GlobalSettingsSerializer(SettingsSerializer):
             'description',
             'type',
             'choices',
+            'model_name',
         ]
 
 
@@ -96,6 +99,7 @@ class UserSettingsSerializer(SettingsSerializer):
             'user',
             'type',
             'choices',
+            'model_name',
         ]
 
 
@@ -124,6 +128,7 @@ class GenericReferencedSettingSerializer(SettingsSerializer):
                 'description',
                 'type',
                 'choices',
+                'model_name',
             ]
 
         # set Meta class

InvenTree/plugin/models.py

@@ -102,7 +102,7 @@ class PluginConfig(models.Model):
         return ret
 
 
-class PluginSetting(common.models.GenericReferencedSettingClass, common.models.BaseInvenTreeSetting):
+class PluginSetting(common.models.BaseInvenTreeSetting):
     """
     This model represents settings for individual plugins
     """
@@ -112,7 +112,13 @@ class PluginSetting(common.models.GenericReferencedSettingClass, common.models.B
             ('plugin', 'key'),
         ]
 
-    REFERENCE_NAME = 'plugin'
+    plugin = models.ForeignKey(
+        PluginConfig,
+        related_name='settings',
+        null=False,
+        verbose_name=_('Plugin'),
+        on_delete=models.CASCADE,
+    )
 
     @classmethod
     def get_setting_definition(cls, key, **kwargs):
@@ -131,7 +137,7 @@ class PluginSetting(common.models.GenericReferencedSettingClass, common.models.B
 
         if 'settings' not in kwargs:
 
-            plugin = kwargs.pop('plugin', None)
+            plugin = kwargs.pop('plugin')
 
             if plugin:
 
@@ -142,16 +148,18 @@ class PluginSetting(common.models.GenericReferencedSettingClass, common.models.B
 
         return super().get_setting_definition(key, **kwargs)
 
-    plugin = models.ForeignKey(
+    def get_kwargs(self):
-        PluginConfig,
+        """
-        related_name='settings',
+        Explicit kwargs required to uniquely identify a particular setting object,
-        null=False,
+        in addition to the 'key' parameter
-        verbose_name=_('Plugin'),
+        """
-        on_delete=models.CASCADE,
+
-    )
+        return {
+            'plugin': self.plugin,
+        }
 
 
-class NotificationUserSetting(common.models.GenericReferencedSettingClass, common.models.BaseInvenTreeSetting):
+class NotificationUserSetting(common.models.BaseInvenTreeSetting):
     """
     This model represents notification settings for a user
     """
@@ -161,8 +169,6 @@ class NotificationUserSetting(common.models.GenericReferencedSettingClass, commo
             ('method', 'user', 'key'),
         ]
 
-    REFERENCE_NAME = 'method'
-
     @classmethod
     def get_setting_definition(cls, key, **kwargs):
         from common.notifications import storage
@@ -171,6 +177,17 @@ class NotificationUserSetting(common.models.GenericReferencedSettingClass, commo
 
         return super().get_setting_definition(key, **kwargs)
 
+    def get_kwargs(self):
+        """
+        Explicit kwargs required to uniquely identify a particular setting object,
+        in addition to the 'key' parameter
+        """
+
+        return {
+            'method': self.method,
+            'user': self.user,
+        }
+
     method = models.CharField(
         max_length=255,
         verbose_name=_('Method'),

InvenTree/plugin/samples/integration/sample.py

@@ -65,6 +65,11 @@ class SampleIntegrationPlugin(AppMixin, SettingsMixin, UrlsMixin, NavigationMixi
             ],
             'default': 'A',
         },
+        'SELECT_COMPANY': {
+            'name': 'Company',
+            'description': 'Select a company object from the database',
+            'model': 'company.Company',
+        },
     }
 
     NAVIGATION = [

InvenTree/templates/InvenTree/settings/setting.html

@@ -22,6 +22,9 @@
         {{ setting.description }}
     </td>
     <td>
+        {% if setting.model_name %}
+        <b>Model name: {{ setting.model_name }}</b>
+        {% endif %}
         {% if setting.is_bool %}
         <div class='form-check form-switch'>
             <input class='form-check-input boolean-setting' fieldname='{{ setting.key.upper }}' pk='{{ setting.pk }}' setting='{{ setting.key.upper }}' id='setting-value-{{ setting.key.upper }}' type='checkbox' {% if setting.as_bool %}checked=''{% endif %} {% if plugin %}plugin='{{ plugin.slug }}'{% endif %}{% if user_setting %}user='{{request.user.id}}'{% endif %}{% if notification_setting %}notification='{{request.user.id}}'{% endif %}>