Store parsed token as string and allow conversion between various types (issues #64, #69, #90, #93)

src/JsonVariant.cpp

@@ -9,22 +9,111 @@
 #include "../include/ArduinoJson/JsonArray.hpp"
 #include "../include/ArduinoJson/JsonObject.hpp"
 
-using namespace ArduinoJson;
+#include <errno.h>   // for errno
+#include <stdlib.h>  // for strtol, strtod
+
 using namespace ArduinoJson::Internals;
 
-void JsonVariant::writeTo(JsonWriter &writer) const {
-  if (is<const JsonArray &>())
-    as<const JsonArray &>().writeTo(writer);
-  else if (is<const JsonObject &>())
-    as<const JsonObject &>().writeTo(writer);
-  else if (is<const char *>())
-    writer.writeString(as<const char *>());
-  else if (is<long>())
-    writer.writeLong(as<long>());
-  else if (is<bool>())
-    writer.writeBoolean(as<bool>());
-  else if (is<double>()) {
+namespace ArduinoJson {
+
+template <>
+const char *JsonVariant::as<const char *>() const {
+  if (_type == JSON_UNPARSED && _content.asString &&
+      !strcmp("null", _content.asString))
+    return NULL;
+  if (_type == JSON_STRING || _type == JSON_UNPARSED) return _content.asString;
+  return NULL;
+}
+
+template <>
+double JsonVariant::as<double>() const {
+  if (_type >= JSON_DOUBLE_0_DECIMALS) return _content.asDouble;
+
+  if (_type == JSON_LONG || _type == JSON_BOOLEAN)
+    return static_cast<double>(_content.asLong);
+
+  if ((_type == JSON_STRING || _type == JSON_UNPARSED) && _content.asString)
+    return strtod(_content.asString, NULL);
+
+  return 0.0;
+}
+
+template <>
+long JsonVariant::as<long>() const {
+  if (_type == JSON_LONG || _type == JSON_BOOLEAN) return _content.asLong;
+
+  if (_type >= JSON_DOUBLE_0_DECIMALS)
+    return static_cast<long>(_content.asDouble);
+
+  if ((_type == JSON_STRING || _type == JSON_UNPARSED) && _content.asString) {
+    if (!strcmp("true", _content.asString)) return 1;
+    return strtol(_content.asString, NULL, 10);
+  }
+
+  return 0L;
+}
+
+template <>
+String JsonVariant::as<String>() const {
+  if ((_type == JSON_STRING || _type == JSON_UNPARSED) &&
+      _content.asString != NULL)
+    return String(_content.asString);
+
+  if (_type == JSON_LONG || _type == JSON_BOOLEAN)
+    return String(_content.asLong);
+
+  if (_type >= JSON_DOUBLE_0_DECIMALS) {
     uint8_t decimals = static_cast<uint8_t>(_type - JSON_DOUBLE_0_DECIMALS);
-    writer.writeDouble(as<double>(), decimals);
+    return String(_content.asDouble, decimals);
+  }
+
+  String s;
+  printTo(s);
+  return s;
+}
+
+template <>
+bool JsonVariant::is<signed long>() const {
+  if (_type == JSON_LONG) return true;
+
+  if (_type != JSON_UNPARSED || _content.asString == NULL) return false;
+
+  char *end;
+  errno = 0;
+  strtol(_content.asString, &end, 10);
+
+  return *end == '\0' && errno == 0;
+}
+
+template <>
+bool JsonVariant::is<double>() const {
+  if (_type >= JSON_DOUBLE_0_DECIMALS) return true;
+
+  if (_type != JSON_UNPARSED || _content.asString == NULL) return false;
+
+  char *end;
+  errno = 0;
+  strtod(_content.asString, &end);
+
+  return *end == '\0' && errno == 0 && !is<long>();
+}
+
+void JsonVariant::writeTo(JsonWriter &writer) const {
+  if (_type == JSON_ARRAY) _content.asArray->writeTo(writer);
+
+  if (_type == JSON_OBJECT) _content.asObject->writeTo(writer);
+
+  if (_type == JSON_STRING) writer.writeString(_content.asString);
+
+  if (_type == JSON_UNPARSED) writer.writeRaw(_content.asString);
+
+  if (_type == JSON_LONG) writer.writeLong(_content.asLong);
+
+  if (_type == JSON_BOOLEAN) writer.writeBoolean(_content.asLong);
+
+  if (_type >= JSON_DOUBLE_0_DECIMALS) {
+    uint8_t decimals = static_cast<uint8_t>(_type - JSON_DOUBLE_0_DECIMALS);
+    writer.writeDouble(_content.asDouble, decimals);
   }
 }
+}