From fd506261b2eae5aaea915fe185e16d99cc32409d Mon Sep 17 00:00:00 2001
From: Dominik George <nik@naturalnet.de>
Date: Sat, 18 Jan 2020 22:58:51 +0100
Subject: [PATCH] Add method to inject fields into extensible models
Advances #141.
---
aleksis/core/mixins.py | 38 ++++++++++++++++++++++++++++++++++++--
1 file changed, 36 insertions(+), 2 deletions(-)
diff --git a/aleksis/core/mixins.py b/aleksis/core/mixins.py
index ad159fed2..80c374a55 100644
--- a/aleksis/core/mixins.py
+++ b/aleksis/core/mixins.py
@@ -5,10 +5,12 @@ from django.db import models
from django.db.models import QuerySet
from easyaudit.models import CRUDEvent
+from jsonstore.fields import JSONField, JSONFieldMixin
-class ExtensibleModel(object):
- """ Allow injection of code from AlekSIS apps to extend model functionality.
+class ExtensibleModel(models.Model):
+ """ Allow injection of fields and code from AlekSIS apps to extend
+ model functionality.
After all apps have been loaded, the code in the `model_extensions` module
in every app is executed. All code that shall be injected into a model goes there.
@@ -19,6 +21,8 @@ class ExtensibleModel(object):
from datetime import date, timedelta
+ from jsonstore import CharField
+
from aleksis.core.models import Person
@Person.property
@@ -29,6 +33,8 @@ class ExtensibleModel(object):
def age(self) -> timedelta:
return self.date_of_birth - date.today()
+ Person.field(shirt_size=CharField())
+
For a more advanced example, using features from the ORM, see AlekSIS-App-Chronos
and AlekSIS-App-Alsijil.
@@ -37,6 +43,8 @@ class ExtensibleModel(object):
- Dominik George <dominik.george@teckids.org>
"""
+ extended_data = JSONField(blank=True, null=True)
+
@classmethod
def _safe_add(cls, obj: Any, name: Optional[str]) -> None:
# Decide the name for the attribute
@@ -67,6 +75,32 @@ class ExtensibleModel(object):
cls._safe_add(func, func.__name__)
+ @classmethod
+ def field(cls, **kwargs) -> None:
+ """ Adds the passed jsonstore field. Must be one of the fields in
+ django-jsonstore.
+
+ Accepts exactly one keyword argument, with the name being the desired
+ model field name and the value the field instance.
+ """
+
+ # Force kwargs to be exactly one argument
+ if len(kwargs) != 1:
+ raise TypeError("field() takes 1 keyword argument but %d were given" % len(kwargs))
+ name, field = kwargs.popitem()
+
+ # Force the field to be one of the jsonstore fields
+ if JSONFieldMixin not in field.__class__.__mro__:
+ raise TypeError("Only jsonstore fields can be added to models.")
+
+ # Force use of the one JSONField defined in this mixin
+ field.json_field_name = "extended_data"
+
+ cls._safe_add(field, name)
+
+ class Meta:
+ abstract = True
+
class CRUDMixin(models.Model):
class Meta:
--
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