First version

jsignature/fields.py

@@ -0,0 +1,54 @@
+"""
+    Provides a django model field to store a signature captured
+    with jSignature jQuery plugin
+"""
+import json
+from django.db import models
+from django.core import validators
+from django.core.exceptions import ValidationError
+from .forms import JSignatureField as JSignatureFormField
+
+class JSignatureField(models.Field):
+    """
+    A model field handling a signature captured with jSignature
+    """
+    description = "A signature captured with jSignature"
+    __metaclass__ = models.SubfieldBase
+
+    def get_internal_type(self):
+        return 'TextField'
+
+    def to_python(self, value):
+        """
+        Validates that the input can be red as a JSON object. Returns a Python
+        datetime.date object.
+        """
+        if value in validators.EMPTY_VALUES:
+            return None
+        elif isinstance(value, list):
+            return value
+        try:
+            return json.loads(value)
+        except ValueError:
+            raise ValidationError('Invalid JSON format.')
+
+    def get_prep_value(self, value):
+        return self.to_python(value)
+
+    def get_db_prep_value(self, value, connection, prepared=False):
+        if value in validators.EMPTY_VALUES:
+            return None
+        elif isinstance(value, basestring):
+            return value
+        elif isinstance(value, list):
+            return json.dumps(value)
+        raise ValidationError('Invalid format.')
+
+    def formfield(self, **kwargs):
+        defaults = {'form_class': JSignatureFormField}
+        defaults.update(kwargs)
+        return super(JSignatureField, self).formfield(**defaults)
+
+
+from south.modelsinspector import add_introspection_rules
+add_introspection_rules([], ["jsignature.fields.JSignatureField"])