Merge pull request #26 from 18F/master

Pass `json_dump_args` to json.dumps

django_pgjson/fields.py

@@ -16,8 +16,13 @@
 
 
 class JsonAdapter(psycopg2.extras.Json):
+
+    def __init__(self, *args, **kwargs):
+        self.json_dump_args = kwargs.pop('json_dump_args', {})
+        super(JsonAdapter, self).__init__(*args, **kwargs)
+
     def dumps(self, obj):
-        return json.dumps(obj, cls=DjangoJSONEncoder)
+        return json.dumps(obj, cls=DjangoJSONEncoder, **self.json_dump_args)
 
 
 psycopg2.extensions.register_adapter(dict, JsonAdapter)
@@ -31,14 +36,19 @@ def dumps(self, obj):
 class JsonField(six.with_metaclass(models.SubfieldBase, models.Field)):
     empty_strings_allowed = False
 
+    def __init__(self, *args, **kwargs):
+        self.json_dump_args = kwargs.pop('json_dump_args', {})
+        super(JsonField, self).__init__(*args, **kwargs)
+
     def db_type(self, connection):
         if get_version(connection) < 90200:
             raise RuntimeError("django_pgjson does not supports postgresql version < 9.2")
         return "json"
 
     def value_to_string(self, obj):
         value = self._get_val_from_obj(obj)
-        return json.dumps(self.get_prep_value(value), cls=DjangoJSONEncoder)
+        return json.dumps(self.get_prep_value(value), cls=DjangoJSONEncoder,
+                          **self.json_dump_args)
 
     def get_default(self):
         if self.has_default():
@@ -57,7 +67,7 @@ def to_python(self, value):
         return value
 
     def formfield(self, **kwargs):
-        defaults = {'form_class': JsonFormField}
+        defaults = {'form_class': jsonFormField(self.json_dump_args)}
         defaults.update(kwargs)
         return super(JsonField, self).formfield(**defaults)
 
@@ -98,7 +108,8 @@ def get_prep_lookup(self, lookup_type, value, prepared=False):
         """
         if lookup_type in ['jcontains']:
             if not isinstance(value, six.string_types):
-                value = json.dumps(value, cls=DjangoJSONEncoder)
+                value = json.dumps(value, cls=DjangoJSONEncoder,
+                                   **self.json_dump_args)
         if lookup_type in ['jhas_any', 'jhas_all']:
             if isinstance(value, six.string_types):
                 value = [value]
@@ -130,14 +141,21 @@ def get_prep_lookup(self, lookup_type, value, prepared=False):
     JsonBField.register_lookup(JsonBHasAllLookup)
 
 
+# return a class of JsonFormField
 
-class JsonFormField(forms.CharField):
-    widget = forms.Textarea
+def jsonFormField(json_dump_args_):
+    class JsonFormField(forms.CharField):
 
-    def prepare_value(self, value):
-        if isinstance(value, six.string_types):
-            return value
-        return json.dumps(value, cls=DjangoJSONEncoder)
+        json_dump_args = json_dump_args_
+
+        widget = forms.Textarea
+
+        def prepare_value(self, value):
+            if isinstance(value, six.string_types):
+                return value
+            return json.dumps(value, cls=DjangoJSONEncoder,
+                              **self.json_dump_args)
+    return JsonFormField
 
 
 # South compatibility

doc/doc.asciidoc

@@ -197,6 +197,21 @@ We will implement support for more of the jsonb operators in the near future.
 See http://www.postgresql.org/docs/9.4/static/datatype-json.html for more
 information on what's possible, and feel free to send a pull request.
 
+Formatting JSON output
+^^^^^^^^^^^^^^^^^^^^^^
+
+To control the format of serialized JSON, you may define a `json_dump_args`
+dict for a field.  Its contents will be passed as arguments to `json.dumps`.
+
+----
+
+    data = JsonField(json_dump_args={'indent': 2, 'sort_keys': True})
+    
+----
+
+See https://docs.python.org/3/library/json.html#json.dumps
+for accepted arguments.
+
 Developers
 ----------
 
@@ -248,4 +263,4 @@ How to contribute
 Deprecation policy
 ~~~~~~~~~~~~~~~~~~
 
-At any momment of time, django-pgjson developers will mantain support for two versions of django.
+At any momment of time, django-pgjson developers will mantain support for two versions of django.

tests/pg_json_fields/migrations/0003_textmodelwithindent.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+import django_pgjson.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pg_json_fields', '0002_textmodelwithdefault'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='TextModelWithIndent',
+            fields=[
+                ('id', models.AutoField(primary_key=True, serialize=False, verbose_name='ID', auto_created=True)),
+                ('data', django_pgjson.fields.JsonField()),
+            ],
+        ),
+    ]

tests/pg_json_fields/models.py

@@ -12,3 +12,6 @@ class TextModelB(models.Model):
 
 class TextModelWithDefault(models.Model):
     data = JsonField(blank=True, default={})
+
+class TextModelWithIndent(models.Model):
+    data = JsonField(json_dump_args={'indent': 2})

tests/pg_json_fields/tests.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import unicode_literals
+import json
 
 import django
 from django.contrib.admin import AdminSite, ModelAdmin
@@ -10,6 +11,7 @@
 from django_pgjson.fields import JsonField, JsonBField
 
 from .models import TextModel, TextModelB, TextModelWithDefault
+from .models import TextModelWithIndent
 
 
 class JsonFieldTests(TestCase):
@@ -187,6 +189,13 @@ def test_array_length(self):
             qs = self.model_class.objects.filter(data__array_length=3)
             self.assertEqual(qs.count(), 1)
 
+        def test_indent(self):
+            obj1 = TextModelWithIndent.objects.create(
+                data={"name": "foo", "bar": {"baz": 1}})
+            qs = TextModelWithIndent.objects.filter(data__at_name="foo")
+            serialized_obj1 = serialize('json', qs)
+            self.assertIn('\n  "name":',
+                          json.loads(serialized_obj1)[0]['fields']['data'])
 
 class JsonBFieldTests(JsonFieldTests):
     def setUp(self):

tests/settings.py

@@ -10,8 +10,8 @@
     'default': {
         'ENGINE': 'django.db.backends.postgresql_psycopg2',
         'NAME': 'test',
-        'USER': '',
-        'PASSWORD': '',
+        'USER': 'test',
+        'PASSWORD': 'test',
         'HOST': 'localhost',
         'PORT': '',
     }