proj_create(): add support for compoundCRS and concatenatedOperation …

…named from their components

Support following syntaxes:
- OGC URN combining references for compoundCRS:
  e.g. "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717"
- its GDAL shortcut: e.g. "EPSG:2393+5717"
- OGC URN combining references for concatenated operations:
  e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618"

docs/source/apps/projinfo.rst

@@ -29,12 +29,17 @@ Synopsis
     |    {object_definition} | (-s {srs_def} -t {srs_def})
     |
 
-    where {object_definition} or {object_definition} is a PROJ string, a
-    WKT string, an object name, AUTHORITY:CODE
-    (where AUTHORITY is the name of a CRS authority and CODE the code of a CRS
-    found in the proj.db database) or a OGC URN (such as  "urn:ogc:def:crs:EPSG::4326",
-    "urn:ogc:def:coordinateOperation:EPSG::1671", "urn:ogc:def:ellipsoid:EPSG::7001"
-    or "urn:ogc:def:datum:EPSG::6326")
+    where {object_definition} or {srs_def} is
+
+    - a proj-string,
+    - a WKT string,
+    - an object code (like "EPSG:4326", "urn:ogc:def:crs:EPSG::4326",
+      "urn:ogc:def:coordinateOperation:EPSG::1671"),
+    - a OGC URN combining references for compound coordinate reference systems
+      (e.g "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717" or custom abbreviated
+      syntax "EPSG:2393+5717"),
+    - a OGC URN combining references for concatenated operations
+      (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
 
 Description
 ***********

docs/source/development/reference/functions.rst

@@ -29,9 +29,17 @@ paragraph for more details.
 
 .. c:function:: PJ* proj_create(PJ_CONTEXT *ctx, const char *definition)
 
-    Create a transformation object, or a CRS object, from a proj-string,
-    a WKT string, or object code (like "EPSG:4326", "urn:ogc:def:crs:EPSG::4326",
-    "urn:ogc:def:coordinateOperation:EPSG::1671").
+    Create a transformation object, or a CRS object, from:
+
+    - a proj-string,
+    - a WKT string,
+    - an object code (like "EPSG:4326", "urn:ogc:def:crs:EPSG::4326",
+      "urn:ogc:def:coordinateOperation:EPSG::1671"),
+    - a OGC URN combining references for compound coordinate reference systems
+      (e.g "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717" or custom abbreviated
+      syntax "EPSG:2393+5717"),
+    - a OGC URN combining references for concatenated operations
+      (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
 
     Example call:
 
@@ -110,7 +118,8 @@ paragraph for more details.
 
         - the name of a CRS as found in the PROJ database, e.g "WGS84", "NAD27", etc.
 
-        - more generally any string accepted by :c:func:`proj_create`
+        - more generally any string accepted by :c:func:`proj_create` representing
+          a CRS
 
     An "area of use" can be specified in area. When it is supplied, the more
     accurate transformation between two given systems can be chosen.

include/proj/io.hpp

@@ -993,16 +993,16 @@ class PROJ_GCC_DLL AuthorityFactory {
 
     PROJ_INTERNAL std::list<crs::CompoundCRSNNPtr>
     createCompoundCRSFromExisting(const crs::CompoundCRSNNPtr &crs) const;
+
+    PROJ_INTERNAL crs::CRSNNPtr
+    createCoordinateReferenceSystem(const std::string &code,
+                                    bool allowCompound) const;
     //! @endcond
 
   protected:
     PROJ_INTERNAL AuthorityFactory(const DatabaseContextNNPtr &context,
                                    const std::string &authorityName);
 
-    PROJ_INTERNAL crs::CRSNNPtr
-    createCoordinateReferenceSystem(const std::string &code,
-                                    bool allowCompound) const;
-
     PROJ_INTERNAL crs::GeodeticCRSNNPtr
     createGeodeticCRS(const std::string &code, bool geographicOnly) const;
 

src/iso19111/factory.cpp

@@ -2484,6 +2484,8 @@ crs::CRSNNPtr AuthorityFactory::createCoordinateReferenceSystem(
     return createCoordinateReferenceSystem(code, true);
 }
 
+//! @cond Doxygen_Suppress
+
 crs::CRSNNPtr
 AuthorityFactory::createCoordinateReferenceSystem(const std::string &code,
                                                   bool allowCompound) const {
@@ -2513,6 +2515,9 @@ AuthorityFactory::createCoordinateReferenceSystem(const std::string &code,
     }
     throw FactoryException("unhandled CRS type: " + type);
 }
+
+//! @endcond
+
 // ---------------------------------------------------------------------------
 
 //! @cond Doxygen_Suppress

src/iso19111/io.cpp

@@ -4397,15 +4397,97 @@ static BaseObjectNNPtr createFromUserInput(const std::string &text,
             const auto authorities = dbContextNNPtr->getAuthorities();
             for (const auto &authCandidate : authorities) {
                 if (ci_equal(authCandidate, authName)) {
-                    return AuthorityFactory::create(dbContextNNPtr,
-                                                    authCandidate)
-                        ->createCoordinateReferenceSystem(code);
+                    factory =
+                        AuthorityFactory::create(dbContextNNPtr, authCandidate);
+                    try {
+                        return factory->createCoordinateReferenceSystem(code);
+                    } catch (...) {
+                        // EPSG:4326+3855
+                        auto tokensCode = split(code, '+');
+                        if (tokensCode.size() == 2) {
+                            auto crs1(factory->createCoordinateReferenceSystem(
+                                tokensCode[0], false));
+                            auto crs2(factory->createCoordinateReferenceSystem(
+                                tokensCode[1], false));
+                            return CompoundCRS::create(
+                                util::PropertyMap().set(
+                                    IdentifiedObject::NAME_KEY,
+                                    crs1->nameStr() + " + " + crs2->nameStr()),
+                                {crs1, crs2});
+                        }
+                        throw;
+                    }
                 }
             }
             throw;
         }
     }
 
+    // OGC 07-092r2: para 7.5.2
+    // URN combined references for compound coordinate reference systems
+    if (starts_with(text, "urn:ogc:def:crs,")) {
+        if (!dbContext) {
+            throw ParsingException("no database context specified");
+        }
+        auto tokensComma = split(text, ',');
+        std::vector<CRSNNPtr> components;
+        std::string name;
+        for (size_t i = 1; i < tokensComma.size(); i++) {
+            tokens = split(tokensComma[i], ':');
+            if (tokens.size() != 4) {
+                throw ParsingException(
+                    concat("invalid crs component: ", tokensComma[i]));
+            }
+            const auto &type = tokens[0];
+            auto factory =
+                AuthorityFactory::create(NN_NO_CHECK(dbContext), tokens[1]);
+            const auto &code = tokens[3];
+            if (type == "crs") {
+                auto crs(factory->createCoordinateReferenceSystem(code, false));
+                components.emplace_back(crs);
+                if (!name.empty()) {
+                    name += " + ";
+                }
+                name += crs->nameStr();
+            } else {
+                throw ParsingException(
+                    concat("unexpected object type: ", type));
+            }
+        }
+        return CompoundCRS::create(
+            util::PropertyMap().set(IdentifiedObject::NAME_KEY, name),
+            components);
+    }
+
+    // OGC 07-092r2: para 7.5.3
+    // 7.5.3 URN combined references for concatenated operations
+    if (starts_with(text, "urn:ogc:def:coordinateOperation,")) {
+        if (!dbContext) {
+            throw ParsingException("no database context specified");
+        }
+        auto tokensComma = split(text, ',');
+        std::vector<CoordinateOperationNNPtr> components;
+        for (size_t i = 1; i < tokensComma.size(); i++) {
+            tokens = split(tokensComma[i], ':');
+            if (tokens.size() != 4) {
+                throw ParsingException(concat(
+                    "invalid coordinateOperation component: ", tokensComma[i]));
+            }
+            const auto &type = tokens[0];
+            auto factory =
+                AuthorityFactory::create(NN_NO_CHECK(dbContext), tokens[1]);
+            const auto &code = tokens[3];
+            if (type == "coordinateOperation") {
+                auto op(factory->createCoordinateOperation(code, false));
+                components.emplace_back(op);
+            } else {
+                throw ParsingException(
+                    concat("unexpected object type: ", type));
+            }
+        }
+        return ConcatenatedOperation::createComputeMetadata(components, true);
+    }
+
     // urn:ogc:def:crs:EPSG::4326
     if (tokens.size() == 7) {
         if (!dbContext) {
@@ -4510,6 +4592,13 @@ static BaseObjectNNPtr createFromUserInput(const std::string &text,
  *     "urn:ogc:def:coordinateOperation:EPSG::1671",
  *     "urn:ogc:def:ellipsoid:EPSG::7001"
  *     or "urn:ogc:def:datum:EPSG::6326"</li>
+ * <li> OGC URN combining references for compound coordinate reference systems
+ *      e.g. "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717"
+ *      We also accept a custom abbreviated syntax EPSG:2393+5717
+ * </li>
+ * <li> OGC URN combining references for concatenated operations
+ *      e.g.
+ * "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618"</li>
  * <li>an Object name. e.g "WGS 84", "WGS 84 / UTM zone 31N". In that case as
  *     uniqueness is not guaranteed, the function may apply heuristics to
  *     determine the appropriate best match.</li>
@@ -4546,6 +4635,13 @@ BaseObjectNNPtr createFromUserInput(const std::string &text,
  *     "urn:ogc:def:coordinateOperation:EPSG::1671",
  *     "urn:ogc:def:ellipsoid:EPSG::7001"
  *     or "urn:ogc:def:datum:EPSG::6326"</li>
+ * <li> OGC URN combining references for compound coordinate reference systems
+ *      e.g. "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717"
+ *      We also accept a custom abbreviated syntax EPSG:2393+5717
+ * </li>
+ * <li> OGC URN combining references for concatenated operations
+ *      e.g.
+ * "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618"</li>
  * <li>an Object name. e.g "WGS 84", "WGS 84 / UTM zone 31N". In that case as
  *     uniqueness is not guaranteed, the function may apply heuristics to
  *     determine the appropriate best match.</li>

test/unit/test_io.cpp

@@ -8775,6 +8775,39 @@ TEST(io, createFromUserInput) {
     EXPECT_THROW(
         createFromUserInput("urn:ogc:def:unhandled:EPSG::4326", dbContext),
         ParsingException);
+    EXPECT_THROW(createFromUserInput("urn:ogc:def:crs:non_existing_auth::4326",
+                                     dbContext),
+                 NoSuchAuthorityCodeException);
+    EXPECT_THROW(createFromUserInput(
+                     "urn:ogc:def:crs,crs:EPSG::2393,unhandled_type:EPSG::5717",
+                     dbContext),
+                 ParsingException);
+    EXPECT_THROW(createFromUserInput(
+                     "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::unexisting_code",
+                     dbContext),
+                 NoSuchAuthorityCodeException);
+    EXPECT_THROW(
+        createFromUserInput(
+            "urn:ogc:def:crs,crs:EPSG::2393::extra_element,crs:EPSG::EPSG",
+            dbContext),
+        ParsingException);
+    EXPECT_THROW(createFromUserInput("urn:ogc:def:coordinateOperation,"
+                                     "coordinateOperation:EPSG::3895,"
+                                     "unhandled_type:EPSG::1618",
+                                     dbContext),
+                 ParsingException);
+    EXPECT_THROW(
+        createFromUserInput("urn:ogc:def:coordinateOperation,"
+                            "coordinateOperation:EPSG::3895,"
+                            "coordinateOperation:EPSG::unexisting_code",
+                            dbContext),
+        NoSuchAuthorityCodeException);
+    EXPECT_THROW(
+        createFromUserInput("urn:ogc:def:coordinateOperation,"
+                            "coordinateOperation:EPSG::3895::extra_element,"
+                            "coordinateOperation:EPSG::1618",
+                            dbContext),
+        ParsingException);
 
     EXPECT_NO_THROW(createFromUserInput("+proj=longlat", nullptr));
     EXPECT_NO_THROW(createFromUserInput("EPSG:4326", dbContext));
@@ -8789,6 +8822,31 @@ TEST(io, createFromUserInput) {
         createFromUserInput("urn:ogc:def:meridian:EPSG::8901", dbContext));
     EXPECT_NO_THROW(
         createFromUserInput("urn:ogc:def:ellipsoid:EPSG::7030", dbContext));
+    {
+        auto obj = createFromUserInput("EPSG:2393+5717", dbContext);
+        auto crs = nn_dynamic_pointer_cast<CompoundCRS>(obj);
+        ASSERT_TRUE(crs != nullptr);
+        EXPECT_EQ(crs->nameStr(),
+                  "KKJ / Finland Uniform Coordinate System + N60 height");
+    }
+    {
+        auto obj = createFromUserInput(
+            "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717", dbContext);
+        auto crs = nn_dynamic_pointer_cast<CompoundCRS>(obj);
+        ASSERT_TRUE(crs != nullptr);
+        EXPECT_EQ(crs->nameStr(),
+                  "KKJ / Finland Uniform Coordinate System + N60 height");
+    }
+    {
+        auto obj = createFromUserInput("urn:ogc:def:coordinateOperation,"
+                                       "coordinateOperation:EPSG::3895,"
+                                       "coordinateOperation:EPSG::1618",
+                                       dbContext);
+        auto concat = nn_dynamic_pointer_cast<ConcatenatedOperation>(obj);
+        ASSERT_TRUE(concat != nullptr);
+        EXPECT_EQ(concat->nameStr(),
+                  "MGI (Ferro) to MGI (1) + MGI to WGS 84 (3)");
+    }
     EXPECT_NO_THROW(createFromUserInput(
         "GEOGCRS[\"WGS 84\",\n"
         "    DATUM[\"World Geodetic System 1984\",\n"