add hstore column converter to SQLA backend

.travis.yml

@@ -16,7 +16,8 @@ services:
 
 before_script:
   - psql -U postgres -c 'CREATE DATABASE flask_admin_test;'
-  - psql -U postgres -c "CREATE EXTENSION postgis;" flask_admin_test
+  - psql -U postgres -c 'CREATE EXTENSION postgis;' flask_admin_test
+  - psql -U postgres -c 'CREATE EXTENSION hstore;' flask_admin_test
 
 install:
   - pip install "wtforms<$WTFORMS_VERSION.99"

flask_admin/contrib/sqla/fields.py

@@ -4,15 +4,19 @@
 import operator
 
 from wtforms import widgets
-from wtforms.fields import SelectFieldBase
+from wtforms.fields import SelectFieldBase, TextField
 from wtforms.validators import ValidationError
 
+try:
+    from wtforms.fields import _unset_value as unset_value
+except ImportError:
+    from wtforms.utils import unset_value
+
 from .tools import get_primary_key
-from flask_admin._compat import text_type, string_types
-from flask_admin.form import FormOpts
+from flask_admin._compat import text_type, string_types, iteritems
+from flask_admin.form import FormOpts, BaseForm
 from flask_admin.model.fields import InlineFieldList, InlineModelFormField
-from flask_admin.model.widgets import InlineFormWidget
-
+from flask_admin.babel import lazy_gettext
 
 try:
     from sqlalchemy.orm.util import identity_key
@@ -178,6 +182,46 @@ class QuerySelectMultipleField(QuerySelectField):
                     raise ValidationError(self.gettext(u'Not a valid choice'))
 
 
+class HstoreForm(BaseForm):
+    """ Form used in InlineFormField/InlineHstoreList for HSTORE columns """
+    key = TextField(lazy_gettext('Key'))
+    value = TextField(lazy_gettext('Value'))
+
+
+class KeyValue(object):
+    """ Used by InlineHstoreList to simulate a key and a value field instead of
+        the single HSTORE column. """
+    def __init__(self, key=None, value=None):
+        self.key = key
+        self.value = value
+
+
+class InlineHstoreList(InlineFieldList):
+    """ Version of InlineFieldList for use with Postgres HSTORE columns """
+
+    def process(self, formdata, data=unset_value):
+        """ SQLAlchemy returns a dict for HSTORE columns, but WTForms cannot
+            process a dict. This overrides `process` to convert the dict
+            returned by SQLAlchemy to a list of classes before processing. """
+        if isinstance(data, dict):
+            data = [KeyValue(k, v) for k, v in iteritems(data)]
+        super(InlineHstoreList, self).process(formdata, data)
+
+    def populate_obj(self, obj, name):
+        """ Combines each FormField key/value into a dictionary for storage """
+        _fake = type(str('_fake'), (object, ), {})
+
+        output = {}
+        for form_field in self.entries:
+            if not self.should_delete(form_field):
+                fake_obj = _fake()
+                fake_obj.data = KeyValue()
+                form_field.populate_obj(fake_obj, 'data')
+                output[fake_obj.data.key] = fake_obj.data.value
+
+        setattr(obj, name, output)
+
+
 class InlineModelFormList(InlineFieldList):
     """
         Customized inline model form list field.

flask_admin/contrib/sqla/form.py

@@ -12,7 +12,9 @@ from flask_admin._backwards import get_property
 from flask_admin._compat import iteritems
 
 from .validators import Unique
-from .fields import QuerySelectField, QuerySelectMultipleField, InlineModelFormList
+from .fields import (QuerySelectField, QuerySelectMultipleField,
+                     InlineModelFormList, InlineHstoreList, HstoreForm)
+from flask_admin.model.fields import InlineFormField
 from .tools import has_multiple_pks, filter_foreign_columns
 from .ajax import create_ajax_loader
 
@@ -350,6 +352,11 @@ class AdminModelConverter(ModelConverterBase):
     def conv_ARRAY(self, field_args, **extra):
         return form.Select2TagsField(save_as_list=True, **field_args)
 
+    @converts('HSTORE')
+    def conv_HSTORE(self, field_args, **extra):
+        inner_form = field_args.pop('form', HstoreForm)
+        return InlineHstoreList(InlineFormField(inner_form), **field_args)
+
 
 def _resolve_prop(prop):
     """

flask_admin/model/fields.py

@@ -40,7 +40,7 @@ class InlineFieldList(FieldList):
     def display_row_controls(self, field):
         return True
 
-    def process(self, formdata, data=None):
+    def process(self, formdata, data=unset_value):
         res = super(InlineFieldList, self).process(formdata, data)
 
         # Postprocess - contribute flag

flask_admin/tests/sqla/__init__.py

@@ -14,3 +14,15 @@ def setup():
     admin = Admin(app)
 
     return app, db, admin
+
+def setup_postgres():
+    app = Flask(__name__)
+    app.config['SECRET_KEY'] = '1'
+    app.config['CSRF_ENABLED'] = False
+    app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://localhost/flask_admin_test'
+    app.config['SQLALCHEMY_ECHO'] = True
+
+    db = SQLAlchemy(app)
+    admin = Admin(app)
+
+    return app, db, admin

flask_admin/tests/sqla/test_postgres.py

+from nose.tools import eq_, ok_
+
+from . import setup_postgres
+from .test_basic import CustomModelView
+
+from sqlalchemy.dialects.postgresql import HSTORE
+
+
+def test_hstore():
+    app, db, admin = setup_postgres()
+
+    class Model(db.Model):
+        id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+        hstore_test = db.Column(HSTORE)
+
+    db.create_all()
+
+    view = CustomModelView(Model, db.session)
+    admin.add_view(view)
+
+    client = app.test_client()
+
+    rv = client.get('/admin/model/')
+    eq_(rv.status_code, 200)
+
+    rv = client.post('/admin/model/new/', data={
+        'hstore_test-0-key': 'test_val1',
+        'hstore_test-0-value': 'test_val2'
+    })
+    eq_(rv.status_code, 302)
+
+    rv = client.get('/admin/model/')
+    eq_(rv.status_code, 200)
+    data = rv.data.decode('utf-8')
+    ok_('test_val1' in data)
+    ok_('test_val2' in data)
+
+    rv = client.get('/admin/model/edit/?id=1')
+    eq_(rv.status_code, 200)
+    data = rv.data.decode('utf-8')
+    ok_('test_val1' in data)
+    ok_('test_val2' in data)