Added JsonDocument::operator[]

CHANGELOG.md

@@ -19,6 +19,7 @@ HEAD
 * The copy constructor of `DynamicJsonDocument` chooses the capacity according to the memory usage of the source, not from the capacity of the source.
 * Added the ability to create/assign a `StaticJsonDocument`/`DynamicJsonDocument` from a `JsonArray`/`JsonObject`/`JsonVariant`
 * Added `JsonDocument::isNull()`
+* Added `JsonDocument::operator[]`
 
 > ### BREAKING CHANGES
 > 

src/ArduinoJson/Document/JsonDocument.hpp

@@ -9,6 +9,8 @@
 #include "../Variant/VariantRef.hpp"
 #include "../Variant/VariantTo.hpp"
 
+#include "../Array/ArraySubscript.hpp"
+
 namespace ARDUINOJSON_NAMESPACE {
 
 class JsonDocument : public Visitable {
@@ -79,6 +81,48 @@ class JsonDocument : public Visitable {
     return _data;
   }
 
+  // ObjectSubscript operator[](TKey)
+  // TKey = const std::string&, const String&
+  template <typename TKey>
+  FORCE_INLINE typename enable_if<IsString<TKey>::value,
+                                  ObjectSubscript<const TKey&> >::type
+  operator[](const TKey& key) {
+    return getVariant()[key];
+  }
+
+  // ObjectSubscript operator[](TKey);
+  // TKey = const char*, const char[N], const __FlashStringHelper*
+  template <typename TKey>
+  FORCE_INLINE
+      typename enable_if<IsString<TKey*>::value, ObjectSubscript<TKey*> >::type
+      operator[](TKey* key) {
+    return getVariant()[key];
+  }
+
+  // VariantConstRef operator[](TKey) const
+  // TKey = const std::string&, const String&
+  template <typename TKey>
+  FORCE_INLINE typename enable_if<IsString<TKey>::value, VariantConstRef>::type
+  operator[](const TKey& key) const {
+    return getVariant()[key];
+  }
+
+  // VariantConstRef operator[](TKey) const;
+  // TKey = const char*, const char[N], const __FlashStringHelper*
+  template <typename TKey>
+  FORCE_INLINE typename enable_if<IsString<TKey*>::value, VariantConstRef>::type
+  operator[](TKey* key) const {
+    return getVariant()[key];
+  }
+
+  FORCE_INLINE ArraySubscript operator[](size_t index) {
+    return getVariant()[index];
+  }
+
+  FORCE_INLINE VariantConstRef operator[](size_t index) const {
+    return getVariant()[index];
+  }
+
  protected:
   JsonDocument(MemoryPool pool) : _pool(pool) {
     _data.setNull();
@@ -88,10 +132,6 @@ class JsonDocument : public Visitable {
     _data.setNull();
   }
 
-  void copy(const JsonDocument& src) {
-    to<VariantRef>().set(src.as<VariantRef>());
-  }
-
   void replacePool(MemoryPool pool) {
     _pool = pool;
   }

src/ArduinoJson/Operators/VariantSubscripts.hpp

@@ -31,17 +31,17 @@ class VariantSubscripts {
   //
   // ObjectSubscript operator[](TKey) const;
   // TKey = const std::string&, const String&
-  template <typename TString>
+  template <typename TKey>
-  FORCE_INLINE typename enable_if<IsString<TString>::value,
+  FORCE_INLINE typename enable_if<IsString<TKey>::value,
-                                  ObjectSubscript<const TString &> >::type
+                                  ObjectSubscript<const TKey &> >::type
-  operator[](const TString &key) const;
+  operator[](const TKey &key) const;
   //
   // ObjectSubscript operator[](TKey) const;
   // TKey = const char*, const char[N], const __FlashStringHelper*
-  template <typename TString>
+  template <typename TKey>
-  FORCE_INLINE typename enable_if<IsString<TString *>::value,
+  FORCE_INLINE typename enable_if<IsString<TKey *>::value,
-                                  ObjectSubscript<TString *> >::type
+                                  ObjectSubscript<TKey *> >::type
-  operator[](TString *key) const;
+  operator[](TKey *key) const;
 
  private:
   const TImpl *impl() const {

test/JsonDocument/CMakeLists.txt

@@ -7,6 +7,7 @@ add_executable(JsonDocumentTests
 	nesting.cpp
 	isNull.cpp
 	StaticJsonDocument.cpp
+	subscript.cpp
 )
 
 target_link_libraries(JsonDocumentTests catch)

test/JsonDocument/subscript.cpp

@@ -0,0 +1,32 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonDocument::operator[]") {
+  DynamicJsonDocument doc(4096);
+  const JsonDocument& cdoc = doc;
+
+  SECTION("object") {
+    deserializeJson(doc, "{\"hello\":\"world\"}");
+
+    SECTION("const char*") {
+      REQUIRE(doc["hello"] == "world");
+      REQUIRE(cdoc["hello"] == "world");
+    }
+
+    SECTION("std::string") {
+      REQUIRE(doc[std::string("hello")] == "world");
+      REQUIRE(cdoc[std::string("hello")] == "world");
+    }
+  }
+
+  SECTION("array") {
+    deserializeJson(doc, "[\"hello\",\"world\"]");
+
+    REQUIRE(doc[1] == "world");
+    REQUIRE(cdoc[1] == "world");
+  }
+}