Add (Pretty)Writer::RawValue()

Fix #205

include/rapidjson/prettywriter.h

@@ -146,6 +146,18 @@ public:
     bool Key(const Ch* str) { return Key(str, internal::StrLen(str)); }
 
     //@}
+
+    //! Write a raw JSON value.
+    /*!
+        For user to write a stringified JSON as a value.
+
+        \param json A well-formed JSON value. It should not contain null character within [0, length - 1] range.
+        \param length Length of the json.
+        \param type Type of the root of json.
+        \note When using PrettyWriter::RawValue(), the result json may not be indented correctly.
+    */
+    bool RawValue(const Ch* json, size_t length, Type type) { PrettyPrefix(type); return Base::WriteRawValue(json, length); }
+
 protected:
     void PrettyPrefix(Type type) {
         (void)type;

include/rapidjson/writer.h

@@ -198,6 +198,16 @@ public:
 
     //@}
 
+    //! Write a raw JSON value.
+    /*!
+        For user to write a stringified JSON as a value.
+
+        \param json A well-formed JSON value. It should not contain null character within [0, length - 1] range.
+        \param length Length of the json.
+        \param type Type of the root of json.
+    */
+    bool RawValue(const Ch* json, size_t length, Type type) { Prefix(type); return WriteRawValue(json, length); }
+
 protected:
     //! Information for each nested level
     struct Level {
@@ -352,6 +362,15 @@ protected:
     bool WriteStartArray()  { os_->Put('['); return true; }
     bool WriteEndArray()    { os_->Put(']'); return true; }
 
+    bool WriteRawValue(const Ch* json, size_t length) {
+        PutReserve(*os_, length);
+        for (size_t i = 0; i < length; i++) {
+            RAPIDJSON_ASSERT(json[i] != '\0');
+            PutUnsafe(*os_, json[i]);
+        }
+        return true;
+    }
+
     void Prefix(Type type) {
         (void)type;
         if (RAPIDJSON_LIKELY(level_stack_.GetSize() != 0)) { // this value is not at root

test/unittest/prettywritertest.cpp

@@ -159,3 +159,22 @@ TEST(PrettyWriter, FileWriteStream) {
     EXPECT_STREQ(kPrettyJson, json);
     free(json);
 }
+
+TEST(PrettyWriter, RawValue) {
+    StringBuffer buffer;
+    PrettyWriter<StringBuffer> writer(buffer);
+    writer.StartObject();
+    writer.Key("a");
+    writer.Int(1);
+    writer.Key("raw");
+    const char json[] = "[\"Hello\\nWorld\", 123.456]";
+    writer.RawValue(json, strlen(json), kArrayType);
+    writer.EndObject();
+    EXPECT_TRUE(writer.IsComplete());
+    EXPECT_STREQ(
+        "{\n"
+        "    \"a\": 1,\n"
+        "    \"raw\": [\"Hello\\nWorld\", 123.456]\n" // no indentation within raw value
+        "}",
+        buffer.GetString());
+}

test/unittest/writertest.cpp

@@ -425,3 +425,17 @@ TEST(Writer, Inf) {
         EXPECT_FALSE(writer.Double(-inf));
     }
 }
+
+TEST(Writer, RawValue) {
+    StringBuffer buffer;
+    Writer<StringBuffer> writer(buffer);
+    writer.StartObject();
+    writer.Key("a");
+    writer.Int(1);
+    writer.Key("raw");
+    const char json[] = "[\"Hello\\nWorld\", 123.456]";
+    writer.RawValue(json, strlen(json), kArrayType);
+    writer.EndObject();
+    EXPECT_TRUE(writer.IsComplete());
+    EXPECT_STREQ("{\"a\":1,\"raw\":[\"Hello\\nWorld\", 123.456]}", buffer.GetString());
+}