add JSONField to SQLA backend

flask_admin/contrib/geoa/fields.py

-import json
 import warnings
 
 import geoalchemy2
 from flask import current_app
 from shapely.geometry import shape
 from sqlalchemy import func
-from wtforms.fields import TextAreaField
 
-from .widgets import LeafletWidget
-
-
-class JSONField(TextAreaField):
-    def _value(self):
-        if self.raw_data:
-            return self.raw_data[0]
-        if self.data:
-            return self.data
-        return ""
-
-    def process_formdata(self, valuelist):
-        if valuelist:
-            value = valuelist[0]
-            if not value:
-                self.data = None
-                return
-            try:
-                self.data = self.from_json(value)
-            except ValueError:
-                self.data = None
-                raise ValueError(self.gettext('Invalid JSON'))
+from flask_admin.form import JSONField
 
-    def to_json(self, obj):
-        return json.dumps(obj)
-
-    def from_json(self, data):
-        return json.loads(data)
+from .widgets import LeafletWidget
 
 
 class GeoJSONField(JSONField):
     widget = LeafletWidget()
 
-    def __init__(self, label=None, validators=None, geometry_type="GEOMETRY", srid='-1', session=None, **kwargs):
+    def __init__(self, label=None, validators=None, geometry_type="GEOMETRY",
+                 srid='-1', session=None, **kwargs):
         super(GeoJSONField, self).__init__(label, validators, **kwargs)
         self.web_srid = 4326
         self.srid = srid

flask_admin/contrib/sqla/form.py

@@ -350,6 +350,10 @@ class AdminModelConverter(ModelConverterBase):
         inner_form = field_args.pop('form', HstoreForm)
         return InlineHstoreList(InlineFormField(inner_form), **field_args)
 
+    @converts('JSON')
+    def convert_JSON(self, field_args, **extra):
+        return form.JSONField(**field_args)
+
 
 def _resolve_prop(prop):
     """

flask_admin/form/fields.py

 import time
 import datetime
+import json
 
-from wtforms import fields, widgets
+from wtforms import fields
 from flask_admin.babel import gettext
 from flask_admin._compat import text_type, as_unicode
 
@@ -11,7 +12,8 @@ from . import widgets as admin_widgets
 An understanding of WTForms's Custom Widgets is helpful for understanding this code: http://wtforms.simplecodes.com/docs/0.6.2/widgets.html#custom-widgets
 """
 
-__all__ = ['DateTimeField', 'TimeField', 'Select2Field', 'Select2TagsField']
+__all__ = ['DateTimeField', 'TimeField', 'Select2Field', 'Select2TagsField',
+           'JSONField']
 
 
 class DateTimeField(fields.DateTimeField):
@@ -176,3 +178,28 @@ class Select2TagsField(fields.StringField):
             return as_unicode(self.data)
         else:
             return u''
+
+
+class JSONField(fields.TextAreaField):
+    def _value(self):
+        if self.raw_data:
+            return self.raw_data[0]
+        elif self.data:
+            # prevent utf8 characters from being converted to ascii
+            return as_unicode(json.dumps(self.data, ensure_ascii=False))
+        else:
+            return ''
+
+    def process_formdata(self, valuelist):
+        if valuelist:
+            value = valuelist[0]
+
+            # allow saving blank field as None
+            if not value:
+                self.data = None
+                return
+
+            try:
+                self.data = json.loads(valuelist[0])
+            except ValueError:
+                raise ValueError(self.gettext('Invalid JSON'))

flask_admin/model/typefmt.py

+import json
+
 from jinja2 import Markup
 from flask_admin._compat import text_type
 try:
@@ -58,15 +60,28 @@ def enum_formatter(view, value):
     return value.name
 
 
+def dict_formatter(view, value):
+    """
+        Removes unicode entities when displaying dict as string. Also unescapes
+        non-ASCII characters stored in the JSON.
+
+        :param value:
+            Dict to convert to string
+    """
+    return json.dumps(value, ensure_ascii=False)
+
+
 BASE_FORMATTERS = {
     type(None): empty_formatter,
     bool: bool_formatter,
     list: list_formatter,
+    dict: dict_formatter,
 }
 
 EXPORT_FORMATTERS = {
     type(None): empty_formatter,
     list: list_formatter,
+    dict: dict_formatter,
 }
 
 if Enum is not None:

flask_admin/tests/sqla/test_postgres.py

@@ -3,7 +3,7 @@ from nose.tools import eq_, ok_
 from . import setup_postgres
 from .test_basic import CustomModelView
 
-from sqlalchemy.dialects.postgresql import HSTORE
+from sqlalchemy.dialects.postgresql import HSTORE, JSON
 
 
 def test_hstore():
@@ -40,3 +40,38 @@ def test_hstore():
     data = rv.data.decode('utf-8')
     ok_('test_val1' in data)
     ok_('test_val2' in data)
+
+
+def test_json():
+    app, db, admin = setup_postgres()
+
+    class JSONModel(db.Model):
+        id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+        json_test = db.Column(JSON)
+
+    db.create_all()
+
+    view = CustomModelView(JSONModel, db.session)
+    admin.add_view(view)
+
+    client = app.test_client()
+
+    rv = client.get('/admin/jsonmodel/')
+    eq_(rv.status_code, 200)
+
+    rv = client.post('/admin/jsonmodel/new/', data={
+        'json_test': '{"test_key1": "test_value1"}',
+    })
+    eq_(rv.status_code, 302)
+
+    rv = client.get('/admin/jsonmodel/')
+    eq_(rv.status_code, 200)
+    data = rv.data.decode('utf-8')
+    ok_('json_test' in data)
+    ok_('{"test_key1": "test_value1"}' in data)
+
+    rv = client.get('/admin/jsonmodel/edit/?id=1')
+    eq_(rv.status_code, 200)
+    data = rv.data.decode('utf-8')
+    ok_('json_test' in data)
+    ok_('>{"test_key1": "test_value1"}<' in data)