Added support for custom converters (closes #687)

extras/tests/JsonVariant/CMakeLists.txt

@@ -9,6 +9,7 @@ add_executable(JsonVariantTests
 	compare.cpp
 	containsKey.cpp
 	copy.cpp
+	converters.cpp
 	createNested.cpp
 	is.cpp
 	isnull.cpp

extras/tests/JsonVariant/converters.cpp

@@ -0,0 +1,144 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2021
+// MIT License
+
+#include <ArduinoJson.h>
+#include <stdint.h>
+#include <catch.hpp>
+
+namespace {
+struct Date {
+  int day;
+  int month;
+  int year;
+};
+
+bool convertToJson(JsonVariant variant, const Date& date) {
+  variant["day"] = date.day;
+  variant["month"] = date.month;
+  variant["year"] = date.year;
+  return true;
+}
+
+void convertFromJson(Date& date, JsonVariantConst variant) {
+  date.day = variant["day"];
+  date.month = variant["month"];
+  date.year = variant["year"];
+}
+
+bool canConvertFromJson(Date&, JsonVariantConst variant) {
+  return variant["day"].is<int>() && variant["month"].is<int>() &&
+         variant["year"].is<int>();
+}
+}  // namespace
+
+TEST_CASE("Custom converter with overloading") {
+  DynamicJsonDocument doc(4096);
+
+  SECTION("convert JSON to Date") {
+    doc["date"]["day"] = 2;
+    doc["date"]["month"] = 3;
+    doc["date"]["year"] = 2021;
+
+    Date date = doc["date"];
+
+    REQUIRE(date.day == 2);
+    REQUIRE(date.month == 3);
+    REQUIRE(date.year == 2021);
+  }
+
+  SECTION("is<Date>() returns true") {
+    doc["date"]["day"] = 2;
+    doc["date"]["month"] = 3;
+    doc["date"]["year"] = 2021;
+
+    REQUIRE(doc["date"].is<Date>());
+  }
+
+  SECTION("is<Date>() returns false") {
+    doc["date"]["day"] = 2;
+    doc["date"]["month"] = 3;
+    doc["date"]["year"] = "2021";
+
+    REQUIRE(doc["date"].is<Date>() == false);
+  }
+
+  SECTION("convert Date to JSON") {
+    Date date = {19, 3, 2021};
+    doc["date"] = date;
+
+    REQUIRE(doc["date"]["day"] == 19);
+    REQUIRE(doc["date"]["month"] == 3);
+    REQUIRE(doc["date"]["year"] == 2021);
+  }
+}
+
+class Complex {
+ public:
+  explicit Complex(double r, double i) : _real(r), _imag(i) {}
+
+  double real() const {
+    return _real;
+  }
+
+  double imag() const {
+    return _imag;
+  }
+
+ private:
+  double _real, _imag;
+};
+
+namespace ARDUINOJSON_NAMESPACE {
+template <>
+struct Converter<Complex> {
+  static bool toJson(VariantRef variant, const Complex& value) {
+    variant["real"] = value.real();
+    variant["imag"] = value.imag();
+    return true;
+  }
+
+  static Complex fromJson(VariantConstRef variant) {
+    return Complex(variant["real"], variant["imag"]);
+  }
+
+  static bool checkJson(VariantConstRef variant) {
+    return variant["real"].is<double>() && variant["imag"].is<double>();
+  }
+};
+}  // namespace ARDUINOJSON_NAMESPACE
+
+TEST_CASE("Custom converter with specialization") {
+  DynamicJsonDocument doc(4096);
+
+  SECTION("convert JSON to Complex") {
+    doc["value"]["real"] = 2;
+    doc["value"]["imag"] = 3;
+
+    Complex value = doc["value"];
+
+    REQUIRE(value.real() == 2);
+    REQUIRE(value.imag() == 3);
+  }
+
+  SECTION("is<Complex>() returns true") {
+    doc["value"]["real"] = 2;
+    doc["value"]["imag"] = 3;
+
+    REQUIRE(doc["value"].is<Complex>());
+  }
+
+  SECTION("is<Complex>() returns false") {
+    doc["value"]["real"] = 2;
+    doc["value"]["imag"] = "3";
+
+    REQUIRE(doc["value"].is<Complex>() == false);
+  }
+
+  SECTION("convert value to JSON") {
+    doc["value"] = Complex(19, 3);
+
+    REQUIRE(doc["value"]["real"] == 19);
+    REQUIRE(doc["value"]["imag"] == 3);
+  }
+}

extras/tests/JsonVariant/is.cpp

@@ -19,7 +19,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<JsonVariant>() == false);
     CHECK(variant.is<JsonVariantConst>() == false);
     CHECK(variant.is<bool>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<std::string>() == false);
     CHECK(variant.is<float>() == false);
@@ -32,7 +32,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<JsonObject>() == false);
     CHECK(variant.is<JsonArray>() == false);
     CHECK(variant.is<bool>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<std::string>() == false);
     CHECK(variant.is<float>() == false);
@@ -47,7 +47,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<JsonVariantConst>() == true);
     CHECK(variant.is<JsonObject>() == false);
     CHECK(variant.is<JsonArray>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<std::string>() == false);
     CHECK(variant.is<float>() == false);
@@ -62,7 +62,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<JsonVariantConst>() == true);
     CHECK(variant.is<JsonObject>() == false);
     CHECK(variant.is<JsonArray>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<std::string>() == false);
     CHECK(variant.is<float>() == false);
@@ -83,7 +83,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<bool>() == false);
     CHECK(variant.is<JsonObject>() == false);
     CHECK(variant.is<JsonArray>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<std::string>() == false);
   }
 
@@ -97,7 +97,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<bool>() == false);
     CHECK(variant.is<JsonObject>() == false);
     CHECK(variant.is<JsonArray>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<std::string>() == false);
     CHECK(variant.is<MYENUM2>() == false);
@@ -106,7 +106,7 @@ TEST_CASE("JsonVariant::is<T>()") {
   SECTION("const char*") {
     variant.set("4.2");
 
-    CHECK(variant.is<char *>() == true);
+    CHECK(variant.is<const char *>() == true);
     CHECK(variant.is<const char *>() == true);
     CHECK(variant.is<std::string>() == true);
     CHECK(variant.is<JsonVariant>() == true);
@@ -132,7 +132,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<float>() == false);
     CHECK(variant.is<bool>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<MYENUM2>() == false);
   }
 
@@ -148,7 +148,7 @@ TEST_CASE("JsonVariant::is<T>()") {
     CHECK(variant.is<int>() == false);
     CHECK(variant.is<float>() == false);
     CHECK(variant.is<bool>() == false);
-    CHECK(variant.is<char *>() == false);
+    CHECK(variant.is<const char *>() == false);
     CHECK(variant.is<MYENUM2>() == false);
     CHECK(variant.is<JsonVariant>() == true);
     CHECK(variant.is<JsonVariantConst>() == true);
@@ -170,7 +170,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonVariant>() == false);
     CHECK(cvariant.is<JsonVariantConst>() == false);
     CHECK(cvariant.is<bool>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<std::string>() == false);
     CHECK(cvariant.is<float>() == false);
@@ -183,7 +183,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonArray>() == false);
     CHECK(cvariant.is<JsonVariant>() == false);
     CHECK(cvariant.is<bool>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<std::string>() == false);
     CHECK(cvariant.is<float>() == false);
@@ -198,7 +198,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonVariant>() == false);
     CHECK(cvariant.is<JsonObject>() == false);
     CHECK(cvariant.is<JsonArray>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<std::string>() == false);
     CHECK(cvariant.is<float>() == false);
@@ -213,7 +213,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonVariant>() == false);
     CHECK(cvariant.is<JsonObject>() == false);
     CHECK(cvariant.is<JsonArray>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<std::string>() == false);
     CHECK(cvariant.is<float>() == false);
@@ -234,7 +234,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonObject>() == false);
     CHECK(cvariant.is<JsonArray>() == false);
     CHECK(cvariant.is<JsonVariant>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<std::string>() == false);
   }
 
@@ -248,7 +248,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<JsonObject>() == false);
     CHECK(cvariant.is<JsonArray>() == false);
     CHECK(cvariant.is<JsonVariant>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<std::string>() == false);
     CHECK(cvariant.is<MYENUM2>() == false);
@@ -257,7 +257,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
   SECTION("const char*") {
     variant.set("4.2");
 
-    CHECK(cvariant.is<char *>() == true);
+    CHECK(cvariant.is<const char *>() == true);
     CHECK(cvariant.is<const char *>() == true);
     CHECK(cvariant.is<std::string>() == true);
     CHECK(cvariant.is<double>() == false);
@@ -282,7 +282,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<float>() == false);
     CHECK(cvariant.is<bool>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<MYENUM2>() == false);
   }
 
@@ -298,7 +298,7 @@ TEST_CASE("JsonVariantConst::is<T>()") {
     CHECK(cvariant.is<int>() == false);
     CHECK(cvariant.is<float>() == false);
     CHECK(cvariant.is<bool>() == false);
-    CHECK(cvariant.is<char *>() == false);
+    CHECK(cvariant.is<const char *>() == false);
     CHECK(cvariant.is<MYENUM2>() == false);
   }
 }

extras/tests/JsonVariant/undefined.cpp

@@ -47,8 +47,8 @@ TEST_CASE("JsonVariant undefined") {
       REQUIRE(variant.is<unsigned>() == false);
     }
 
-    SECTION("char*") {
-      REQUIRE(variant.is<char*>() == false);
+    SECTION("const char*") {
+      REQUIRE(variant.is<const char*>() == false);
     }
 
     SECTION("double") {

extras/tests/Misc/Readers.cpp

@@ -3,7 +3,7 @@
 // MIT License
 
 #define ARDUINOJSON_ENABLE_ARDUINO_STREAM 1
-#include <ArduinoJson/Deserialization/Reader.hpp>
+#include <ArduinoJson.hpp>
 #include <catch.hpp>
 
 using namespace ARDUINOJSON_NAMESPACE;

extras/tests/Numbers/parseDouble.cpp

@@ -6,8 +6,7 @@
 #define ARDUINOJSON_ENABLE_NAN 1
 #define ARDUINOJSON_ENABLE_INFINITY 1
 
-#include <ArduinoJson/Numbers/parseNumber.hpp>
-#include <ArduinoJson/Variant/VariantImpl.hpp>
+#include <ArduinoJson.hpp>
 #include <catch.hpp>
 
 using namespace ARDUINOJSON_NAMESPACE;

extras/tests/Numbers/parseFloat.cpp

@@ -6,8 +6,7 @@
 #define ARDUINOJSON_ENABLE_NAN 1
 #define ARDUINOJSON_ENABLE_INFINITY 1
 
-#include <ArduinoJson/Numbers/parseNumber.hpp>
-#include <ArduinoJson/Variant/VariantImpl.hpp>
+#include <ArduinoJson.hpp>
 #include <catch.hpp>
 
 using namespace ARDUINOJSON_NAMESPACE;

extras/tests/Numbers/parseInteger.cpp

@@ -3,8 +3,7 @@
 // MIT License
 
 #include <stdint.h>
-#include <ArduinoJson/Numbers/parseNumber.hpp>
-#include <ArduinoJson/Variant/VariantImpl.hpp>
+#include <ArduinoJson.hpp>
 #include <catch.hpp>
 
 using namespace ARDUINOJSON_NAMESPACE;

extras/tests/Numbers/parseNumber.cpp

@@ -2,9 +2,7 @@
 // Copyright Benoit Blanchon 2014-2021
 // MIT License
 
-#include <ArduinoJson/Numbers/Integer.hpp>
-#include <ArduinoJson/Numbers/parseNumber.hpp>
-#include <ArduinoJson/Variant/VariantImpl.hpp>
+#include <ArduinoJson.hpp>
 #include <catch.hpp>
 
 using namespace ARDUINOJSON_NAMESPACE;