Dopracowanie aplikacji django-sponsors.

[wolnelektury.git] / apps / sponsors / fields.py

diff --git a/apps/sponsors/fields.py b/apps/sponsors/fields.py
new file mode 100644 (file)
index 0000000..678788e
--- /dev/null
+++ b/apps/sponsors/fields.py
@@ -0,0 +1,61 @@
+# -*- encoding: utf-8 -*-
+import datetime
+
+from django.conf import settings
+from django.db import models
+from django import forms
+from django.utils import simplejson as json
+
+
+class JSONEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if isinstance(obj, datetime.datetime):
+            return obj.strftime('%Y-%m-%d %H:%M:%S')
+        elif isinstance(obj, datetime.date):
+            return obj.strftime('%Y-%m-%d')
+        elif isinstance(obj, datetime.time):
+            return obj.strftime('%H:%M:%S')
+        return json.JSONEncoder.default(self, obj)
+
+
+def dumps(data):
+    return JSONEncoder().encode(data)
+
+
+def loads(str):
+    return json.loads(str, encoding=settings.DEFAULT_CHARSET)
+
+
+class JSONFormField(forms.CharField):
+    widget = forms.Textarea
+    
+    def clean(self, value):
+        try:
+            loads(value)
+            return value
+        except ValueError, e:
+            raise forms.ValidationError('Enter a valid JSON value. Error: %s' % e)
+
+
+class JSONField(models.TextField):
+    def formfield(self, **kwargs):
+        defaults = {'form_class': JSONFormField}
+        defaults.update(kwargs)
+        return super(JSONField, self).formfield(**defaults)
+
+    def db_type(self):
+        return 'text'
+
+    def get_internal_type(self):
+        return 'TextField'
+
+    def contribute_to_class(self, cls, name):
+        super(JSONField, self).contribute_to_class(cls, name)
+        
+        def get_value(model_instance):
+            return loads(getattr(model_instance, self.attname, None))
+        setattr(cls, 'get_%s_value' % self.name, get_value)
+
+        def set_value(model_instance, json):
+            return setattr(model_instance, self.attname, dumps(json))
+        setattr(cls, 'set_%s_value' % self.name, set_value)