Added a RawlJSONEncoder class for easy json conversion. Issue #6

Author: mikeshultz

README.md

@@ -93,6 +93,13 @@ they were `dict`s, `object`s, or `list`s.  For instance:
 `RawResult` should be suitable for serialization(pickling), but should you need 
 to convert to a python type, use `RawResult.to_dict()` or `RawResult.to_list()`.
 
+### JSON Encoding
+
+In case you want to convert your query results directly to a JSON string for 
+output, you can use RawlJSONEncoder.
+
+    json.dumps(StateModel().all(), cls=RawlJSONEncoder)
+
 ## Testing
 
 Install the dependencies.

rawl/__init__.py

@@ -58,6 +58,8 @@ def get_name(self, pk):
 import warnings
 from enum import IntEnum
 from abc import ABC
+from json import JSONEncoder
+from datetime import datetime
 from psycopg2 import sql
 from psycopg2.pool import ThreadedConnectionPool
 from psycopg2.extensions import (
@@ -460,3 +462,18 @@ def all(self):
 
         return self.select("SELECT {0} FROM " + self.table + ";", 
             self.columns)
+
+class RawlJSONEncoder(JSONEncoder):
+    """ 
+    A JSON encoder that can be used with json.dumps
+
+    Usage
+    -----
+    json.dumps(cls=RawlJSONEncoder)
+    """
+    def default(self, o):
+        if type(o) == datetime:
+            return o.isoformat()
+        elif type(o) == RawlResult:
+            return o.to_dict()
+        return JSONEncoder.default(self, o)

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name = 'rawl',
-    version = '0.2.2b1',
+    version = '0.2.3b1',
     description = 'An ugly raw SQL postgresql db layer',
     url = 'https://github.com/mikeshultz/rawl',
     author = 'Mike Shultz',

tests/test_rawl.py

@@ -2,10 +2,17 @@
 import pytest
 import logging
 import pickle
+import json
 from enum import IntEnum
 from psycopg2 import connect
 from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT
-from rawl import RawlBase, RawlConnection, RawlException, RawlResult
+from rawl import (
+    RawlBase,
+    RawlConnection,
+    RawlException,
+    RawlResult,
+    RawlJSONEncoder
+)
 
 log = logging.getLogger(__name__)
 
@@ -273,6 +280,27 @@ def test_serialization(self, pgdb):
         # Test that it can be unpickled
         assert type(pickle.loads(pickled_result)) == RawlResult
 
+    @pytest.mark.dependency(depends=['test_all', 'test_get_single_rawl'])
+    def test_json_serialization(self, pgdb):
+        """ 
+        Test that a RawlResult object can be serialized properly.
+        """
+
+        RAWL_ID = 1
+
+        mod = TheModel(RAWL_DSN)
+
+        result = mod.all()
+
+        try:
+            json.dumps(result, cls=RawlJSONEncoder)
+            assert True
+        except TypeError as e:
+            if 'serializable' in str(e):
+                assert False
+            else:
+                raise e
+
     @pytest.mark.dependency(depends=['test_all', 'test_get_single_rawl'])
     def test_select_with_columns(self, pgdb):
         """