Fixing image preview on form validation errors #22

Includes:
* Adding new bound_data method to VersatileImagePPOIClickField
* Updating test models & fixture
* Adding test coverage

.gitignore

@@ -34,6 +34,8 @@ docs/_build/
 # Coverage Reports #
 ##################
 .coverage
+htmlcov
+htmlcov/*
 
 # Generated Image #
 #################

tests/fixtures/versatileimagefield.json

@@ -106,7 +106,8 @@
         "optional_image": "exif-orientation-examples/Landscape_8.jpg",
         "optional_image_with_ppoi": "exif-orientation-examples/Landscape_6.jpg",
         "ppoi": "0.5x0.5",
-        "optional_image_with_ppoi_ppoi": "1.0x1.0"
+        "optional_image_with_ppoi_ppoi": "1.0x1.0",
+        "required_text_field": "boo urns"
     },
     "model": "tests.versatileimagewidgettestmodel",
     "pk": 1

tests/models.py

@@ -73,5 +73,8 @@ class VersatileImageWidgetTestModel(models.Model):
         blank=True,
         ppoi_field='optional_image_with_ppoi_ppoi'
     )
+    required_text_field = models.CharField(
+        max_length=20,
+    )
     ppoi = PPOIField()
     optional_image_with_ppoi_ppoi = PPOIField()

tests/tests.py

@@ -940,3 +940,27 @@ def test_field_serialization(self):
                 }
             ]
         )
+
+    def test_bound_form_data(self):
+        "Ensure fields return the correct data after form validation errors."
+        response = self.client.post(
+            '/admin/tests/versatileimagewidgettestmodel/1/',
+            {
+                'required_text_field': ''
+            },
+            follow=True
+        )
+        self.assertEqual(response.status_code, 200)
+        if six.PY2:
+            response_content = str(response.content)
+        else:
+            response_content = str(response.content, encoding='utf-8')
+        self.assertInHTML(
+            (
+                '<img src="/media/__sized__/python-logo-thumbnail-300x300.'
+                'png" id="image_0_imagepreview" data-hidden_field_id='
+                '"id_image_1" data-point_stage_id="image_0_point-stage" '
+                'data-ppoi_id="image_0_ppoi" class="sizedimage-preview"/>'
+            ),
+            response_content
+        )

versatileimagefield/forms.py

@@ -46,6 +46,12 @@ def __init__(self, *args, **kwargs):
             tuple(fields), *args, **kwargs
         )
 
+    def bound_data(self, data, initial):
+        to_return = data
+        if data[0] is None:
+            to_return = initial
+        return to_return
+
 
 class SizedImageCenterpointClickDjangoAdminField(
         VersatileImagePPOIClickField):