Added OffDbRasterField, changed orthophoto type from RasterField to OffDbRasterField

app/models.py

@@ -4,7 +4,6 @@ import shutil
 import zipfile
 
 from django.contrib.auth.models import User
-from django.contrib.gis.db import models as gismodels
 from django.contrib.gis.gdal import GDALRaster
 from django.contrib.postgres import fields
 from django.core.exceptions import ValidationError
@@ -18,6 +17,7 @@ from guardian.models import UserObjectPermissionBase
 from guardian.shortcuts import get_perms_for_model, assign_perm
 
 from app import pending_actions
+from app.postgis import OffDbRasterField
 from nodeodm import status_codes
 from nodeodm.exceptions import ProcessingException
 from nodeodm.models import ProcessingNode
@@ -139,7 +139,7 @@ class Task(models.Model):
     ground_control_points = models.FileField(null=True, blank=True, upload_to=gcp_directory_path, help_text="Optional Ground Control Points file to use for processing")
 
     # georeferenced_model
-    orthophoto = gismodels.RasterField(null=True, blank=True, srid=4326, help_text="Orthophoto created by OpenDroneMap")
+    orthophoto = OffDbRasterField(null=True, blank=True, srid=4326, help_text="Orthophoto created by OpenDroneMap")
     # textured_model
     # mission
     created_at = models.DateTimeField(default=timezone.now, help_text="Creation date")

app/postgis.py

@@ -7,11 +7,14 @@ from django.contrib.gis.db.backends.postgis.pgraster import (
     STRUCT_SIZE,
     pack)
 from django.contrib.gis.db.backends.postgis.pgraster import chunk, unpack
-from django.contrib.gis.db.models.fields import RasterField
+from django.contrib.gis.db.models.fields import RasterField, BaseSpatialField
+from django.contrib.gis.gdal import GDALException
+from django.contrib.gis.gdal import GDALRaster
 from django.forms import ValidationError
 from django.utils.translation import ugettext_lazy as _
 
-class OutOfDbRasterField(RasterField):
+
+class OffDbRasterField(RasterField):
     """
     Out-of-db Raster field for GeoDjango -- evaluates into GDALRaster objects.
     """
@@ -19,14 +22,42 @@ class OutOfDbRasterField(RasterField):
     description = _("Out-of-db Raster Field")
 
     def from_db_value(self, value, expression, connection, context):
-        return connection.ops.parse_raster(value)
+        return from_pgraster(value, True)
+
+    def get_db_prep_save(self, value, connection):
+        """
+        Prepare the value for saving in the database.
+        """
+        if not value:
+            return None
+        else:
+            return to_pgraster(value, True)
 
     def get_db_prep_value(self, value, connection, prepared=False):
         self._check_connection(connection)
         # Prepare raster for writing to database.
         if not prepared:
-            value = connection.ops.deconstruct_raster(value)
-        return super(OutOfDbRasterField, self).get_db_prep_value(value, connection, prepared)
+            value = to_pgraster(value, True)
+
+        # Call RasterField's base class get_db_prep_value
+        return BaseSpatialField.get_db_prep_value(self, value, connection, prepared)
+
+    def get_raster_prep_value(self, value, is_candidate):
+        """
+        Return a GDALRaster if conversion is successful, otherwise return None.
+        """
+        if isinstance(value, GDALRaster):
+            return value
+        elif is_candidate:
+            try:
+                return GDALRaster(value)
+            except GDALException:
+                pass
+        elif isinstance(value, (dict, str)):
+            try:
+                return GDALRaster(value)
+            except GDALException:
+                raise ValueError("Couldn't create spatial object from lookup value '%s'." % value)
 
 
 class POSTGIS_BANDTYPES(object):
@@ -35,7 +66,7 @@ class POSTGIS_BANDTYPES(object):
     BANDTYPE_FLAG_ISNODATA = 1 << 5
 
 
-def from_pgraster(data):
+def from_pgraster(data, offdb = False):
     """
     Convert a PostGIS HEX String into a dictionary.
     """
@@ -111,16 +142,18 @@ def from_pgraster(data):
     if len(set(pixeltypes)) != 1:
         raise ValidationError("Band pixeltypes are not all equal.")
 
-
-    return {
-        'srid': int(header[9]),
-        'width': header[10], 'height': header[11],
-        'datatype': pixeltypes[0],
-        'origin': (header[5], header[6]),
-        'scale': (header[3], header[4]),
-        'skew': (header[7], header[8]),
-        'bands': bands,
-    }
+    if offdb and len(bands) > 0:
+        return bands[0]['path']
+    else:
+        return {
+            'srid': int(header[9]),
+            'width': header[10], 'height': header[11],
+            'datatype': pixeltypes[0],
+            'origin': (header[5], header[6]),
+            'scale': (header[3], header[4]),
+            'skew': (header[7], header[8]),
+            'bands': bands,
+        }
 
 
 def to_pgraster(rast, offdb = False):

app/tests/test_fields.py

@@ -1,22 +0,0 @@
-from django.contrib.gis.gdal import GDALRaster
-
-from .classes import BootTestCase
-from app.fields import from_pgraster, to_pgraster
-import os
-
-class TestApi(BootTestCase):
-    def setUp(self):
-        pass
-
-    def tearDown(self):
-        pass
-
-    def test_pgraster_functions(self):
-        # Make sure conversion from PostGIS <---> GDALRaster works
-        # for out-of-db
-        raster = GDALRaster(os.path.join("app", "fixtures", "orthophoto.tif"))
-
-        self.assertTrue(raster.srid == 32615)
-        self.assertTrue(raster.width == 212)
-
-        #hexwkb =

app/tests/test_postgis.py

@@ -0,0 +1,38 @@
+from django.contrib.gis.gdal import GDALRaster
+
+from .classes import BootTestCase
+from app.postgis import from_pgraster, to_pgraster
+import os
+
+class TestApi(BootTestCase):
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_pgraster_functions(self):
+        # Make sure conversion from PostGIS <---> GDALRaster works
+        # for out-of-db
+        raster = GDALRaster(os.path.join("app", "fixtures", "orthophoto.tif"))
+
+        self.assertTrue(raster.srid == 32615)
+        self.assertTrue(raster.width == 212)
+
+        # Classic
+        hexwkb = to_pgraster(raster)
+        deserialized_raster = GDALRaster(from_pgraster(hexwkb))
+        self.assertTrue(len(deserialized_raster.bands) == 4)
+        self.assertTrue(deserialized_raster.srid == raster.srid)
+        self.assertTrue(deserialized_raster.width == raster.width)
+        self.assertTrue(deserialized_raster.height == raster.height)
+
+        # Off-db
+        hexwkb = to_pgraster(raster, True)
+        deserialized_raster = GDALRaster(from_pgraster(hexwkb, True))
+
+        self.assertTrue(deserialized_raster.name == raster.name)
+        self.assertTrue(deserialized_raster.srid == raster.srid)
+        self.assertTrue(deserialized_raster.width == raster.width)
+        self.assertTrue(deserialized_raster.height == raster.height)
+