FIX Feature and FeatureCollection support to implement geometry normalization

CHANGES_NEXT_RELEASE

@@ -1,4 +1,4 @@
-- Add: support for Feature and FeaturesCollection GeoJSON types in entity locations (#4114)
+- Add: support for Feature and FeaturesCollection GeoJSON types (normalizing geometries) in entity locations (#4114)
 - Add: support to null element in string list filters (e.g. q=A:foo,null) (#4120)
 - Fix: allow limit=0 in all paginated operations in the NGSIv2 API (entities, entity types, subscriptions and registrations) (#1492)
 - Add: conditions.alterationTypes subscription fuctionality (#1494)

doc/manuals/user/ngsiv2_implementation_notes.md

@@ -230,17 +230,27 @@ We have successfully tested the following types:
 * MultiLineString
 * Polygon
 * MultiPolygon
-* Feature (using the value of `geometry` field at the first level)
 
-On the contrary, the following types doesn't work (you will get a "Database Error" if you try to use them):
+More information on the tests conducted can be found [here](https://github.com/telefonicaid/fiware-orion/issues/3586).
 
-* GeometryCollection
+The types `Feature` and `FeatureCollection` are also supported, but in a special way. You can
+use `Feature` or `FeatureCollection` to create/update `geo:json` attributes. However, when
+the attribute value is retrieved (GET resposes or notifictaions) you will get only the content of:
 
-With regards to `FeatureCollection`, it is supported only if it contains a single Feature (i.e.
-the `features` field has only one element), in which case the value of `geometry` field of
-such element is used.
+* the `geometry` field, in the case of `Feature`
+* the `geometry` field of the first item of the `features` array, in the case of `FeatureCollection`
 
-More information on the tests conducted can be found [here](https://github.com/telefonicaid/fiware-orion/issues/3586).
+Note that actually Orion stores the full value used at `Feature` or `FeatureCollection`
+creation/updating time. However, from the point of view of normalization with other `geo:json` types,
+it has been decided to return only the `geometry` part. In the future, maybe a flag to return
+the full content would be implemented (more detail [in this issue](https://github.com/telefonicaid/fiware-orion/issues/4125)).
+
+With regards to `FeatureCollection`, it is only accepted at creation/update time only if it contains a single 
+`Feature` (i.e. the `features` field has only one element). Otherwise , Orion would return an `BadRequest`error.
+
+
+The only GeoJSON type not supported at all is `GeometryCollection`. You will get a "Database Error"
+if you try to use them).
 
 ## Legacy attribute format in notifications
 

src/lib/mongoBackend/location.cpp

@@ -98,6 +98,79 @@ static bool stringArray2coords
 
 
 
+/* ****************************************************************************
+*
+* getGeometryFromFeature -
+*/
+static orion::CompoundValueNode* getGeometryFromFeature(orion::CompoundValueNode* feature)
+{
+  for (unsigned int ix = 0; ix < feature->childV.size(); ++ix)
+  {
+    orion::CompoundValueNode* childP = feature->childV[ix];
+    if (childP->name == "geometry")
+    {
+      return childP;
+    }
+  }
+
+  LM_E(("Runtime Error (geometry field expected in GeoJson Feature)"));
+  return NULL;
+}
+
+
+
+/* ****************************************************************************
+*
+* getGeometryFromFeatureCollection -
+*/
+static orion::CompoundValueNode* getGeometryFromFeatureCollection(orion::CompoundValueNode* featureCollection)
+{
+  for (unsigned int ix = 0; ix < featureCollection->childV.size(); ++ix)
+  {
+    orion::CompoundValueNode* childP = featureCollection->childV[ix];
+    if (childP->name == "features")
+    {
+      return getGeometryFromFeature(featureCollection->childV[ix]->childV[0]);
+    }
+  }
+
+  LM_E(("Runtime Error (feature field expected in GeoJson FeatureCollection)"));
+  return NULL;
+}
+
+
+
+/* ****************************************************************************
+*
+* getGeometry -
+*
+* Get geometry compound value from attribute, taking into account special GeoJSON
+* types such as Feature and FeatureCollection
+*/
+orion::CompoundValueNode* getGeometry(orion::CompoundValueNode* compoundValueP)
+{
+  for (unsigned int ix = 0; ix < compoundValueP->childV.size(); ++ix)
+  {
+     orion::CompoundValueNode* childP = compoundValueP->childV[ix];
+     if ((childP->name == "type") && (childP->valueType == orion::ValueTypeString))
+     {
+       if (childP->stringValue == "Feature")
+       {
+         return getGeometryFromFeature(compoundValueP);
+       }
+       if (childP->stringValue == "FeatureCollection")
+       {
+         return getGeometryFromFeatureCollection(compoundValueP);
+       }
+     }
+  }
+
+  // Regular geo:json
+  return compoundValueP;
+}
+
+
+
 /* ****************************************************************************
 *
 * isFeatureType -
@@ -150,7 +223,11 @@ static bool isFeatureCollectionType(CompoundValueNode* featureCollection, orion:
 }
 
 
-
+/* ****************************************************************************
+*
+* isSpecialGeoJsonType -
+*
+*/
 static bool isSpecialGeoJsonType(const ContextAttribute* caP, orion::BSONObjBuilder* geoJson, ApiVersion apiVersion)
 {
   if (caP->compoundValueP == NULL)

src/lib/mongoBackend/location.h

@@ -83,4 +83,15 @@ extern bool processLocationAtAppendAttribute
   OrionError*              oe
 );
 
+
+
+/* ****************************************************************************
+*
+* getGeometry -
+*
+* Get geometry compound value from attribute, taking into account special GeoJSON
+* types such as Feature and FeatureCollection
+*/
+extern orion::CompoundValueNode* getGeometry(orion::CompoundValueNode* compoundValueP);
+
 #endif  // SRC_LIB_MONGOBACKEND_LOCATION_H_

src/lib/ngsi/ContextAttribute.cpp

@@ -42,6 +42,7 @@
 #include "rest/OrionError.h"
 #include "parse/CompoundValueNode.h"
 
+#include "mongoBackend/location.h"
 #include "mongoBackend/dbConstants.h"
 #include "mongoBackend/dbFieldEncoding.h"
 #include "mongoBackend/compoundValueBson.h"
@@ -959,7 +960,18 @@ std::string ContextAttribute::toJson(const std::vector<std::string>&  metadataFi
   //
   if (compoundValueP != NULL)
   {
-    jh.addRaw("value", compoundValueP->toJson());
+    orion::CompoundValueNode* childToRenderP = compoundValueP;
+    if (type == GEO_JSON)
+    {
+      childToRenderP = getGeometry(compoundValueP);
+    }
+
+    // Some internal error conditions in getGeometryToRender() (e.g. out of band manipulation
+    // of DB entities) may lead to NULL, so the check is needed
+    if (childToRenderP != NULL)
+    {
+      jh.addRaw("value", childToRenderP->toJson());
+    }
   }
   else if (valueType == orion::ValueTypeNumber)
   {

test/functionalTest/cases/4114_geojson_feature_support/geojson_feature_support.test

@@ -31,13 +31,13 @@ brokerStart CB
 
 #
 # 01. Create entity with geo:json using Feature type
-# 02. Get entity and see Feature
+# 02. Get entity and see Feature geometry
 # 03. Geoquery covering the location returns the entity
 # 04. Update entity with a regular geo:json Point
 # 05. Get entity and see Point
 # 06. Geoquery covering the location returns the entity
 # 07. Update entity with a Feature again
-# 08. Get entity and see Feature
+# 08. Get entity and see Feature geometry
 # 09. Geoquery covering the location returns the entity
 #
 
@@ -68,8 +68,8 @@ echo
 echo
 
 
-echo "02. Get entity and see Feature"
-echo "=============================="
+echo "02. Get entity and see Feature geometry"
+echo "======================================="
 orionCurl --url /v2/entities/E
 echo
 echo
@@ -140,8 +140,8 @@ echo
 echo
 
 
-echo "08. Get entity and see Feature"
-echo "=============================="
+echo "08. Get entity and see Feature geometry"
+echo "======================================="
 orionCurl --url /v2/entities/E
 echo
 echo
@@ -165,10 +165,10 @@ Date: REGEX(.*)
 
 
 
-02. Get entity and see Feature
-==============================
+02. Get entity and see Feature geometry
+=======================================
 HTTP/1.1 200 OK
-Content-Length: 227
+Content-Length: 133
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
@@ -179,17 +179,11 @@ Date: REGEX(.*)
         "metadata": {},
         "type": "geo:json",
         "value": {
-            "geometry": {
-                "coordinates": [
-                    -3.612711914,
-                    40.539019781
-                ],
-                "type": "Point"
-            },
-            "properties": {
-                "label": "-3.6127119138731127, 40.53901978067972"
-            },
-            "type": "Feature"
+            "coordinates": [
+                -3.612711914,
+                40.539019781
+            ],
+            "type": "Point"
         }
     },
     "type": "T"
@@ -199,7 +193,7 @@ Date: REGEX(.*)
 03. Geoquery covering the location returns the entity
 =====================================================
 HTTP/1.1 200 OK
-Content-Length: 229
+Content-Length: 135
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
@@ -211,17 +205,11 @@ Date: REGEX(.*)
             "metadata": {},
             "type": "geo:json",
             "value": {
-                "geometry": {
-                    "coordinates": [
-                        -3.612711914,
-                        40.539019781
-                    ],
-                    "type": "Point"
-                },
-                "properties": {
-                    "label": "-3.6127119138731127, 40.53901978067972"
-                },
-                "type": "Feature"
+                "coordinates": [
+                    -3.612711914,
+                    40.539019781
+                ],
+                "type": "Point"
             }
         },
         "type": "T"
@@ -297,10 +285,10 @@ Date: REGEX(.*)
 
 
 
-08. Get entity and see Feature
-==============================
+08. Get entity and see Feature geometry
+=======================================
 HTTP/1.1 200 OK
-Content-Length: 229
+Content-Length: 134
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
@@ -311,17 +299,11 @@ Date: REGEX(.*)
         "metadata": {},
         "type": "geo:json",
         "value": {
-            "geometry": {
-                "coordinates": [
-                    -23.612711914,
-                    50.539019781
-                ],
-                "type": "Point"
-            },
-            "properties": {
-                "label": "-23.6127119138731127, 50.53901978067972"
-            },
-            "type": "Feature"
+            "coordinates": [
+                -23.612711914,
+                50.539019781
+            ],
+            "type": "Point"
         }
     },
     "type": "T"
@@ -331,7 +313,7 @@ Date: REGEX(.*)
 09. Geoquery covering the location returns the entity
 =====================================================
 HTTP/1.1 200 OK
-Content-Length: 231
+Content-Length: 136
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
@@ -343,17 +325,11 @@ Date: REGEX(.*)
             "metadata": {},
             "type": "geo:json",
             "value": {
-                "geometry": {
-                    "coordinates": [
-                        -23.612711914,
-                        50.539019781
-                    ],
-                    "type": "Point"
-                },
-                "properties": {
-                    "label": "-23.6127119138731127, 50.53901978067972"
-                },
-                "type": "Feature"
+                "coordinates": [
+                    -23.612711914,
+                    50.539019781
+                ],
+                "type": "Point"
             }
         },
         "type": "T"