Add a method to disable unicode escaping in json string (#491)

config.example.json

@@ -136,6 +136,8 @@
         //files is the path where the csp files locate. If the path isn't prefixed with /, it is relative 
         //path of the current working directory.
         "dynamic_views_output_path": "",
+        //enable_unicode_escaping_in_json: true by default, enable unicode escaping in json.
+        "enable_unicode_escaping_in_json": true,
         //log: Set log output, drogon output logs to stdout by default
         "log": {
             //log_path: Log file path,empty by default,in which case,logs are output to the stdout

drogon_ctl/templates/config.csp

@@ -136,6 +136,8 @@
         //files is the path where the csp files locate. If the path isn't prefixed with /, it is relative 
         //path of the current working directory.
         "dynamic_views_output_path": "",
+        //enable_unicode_escaping_in_json: true by default, enable unicode escaping in json.
+        "enable_unicode_escaping_in_json": true,
         //log: Set log output, drogon output logs to stdout by default
         "log": {
             //log_path: Log file path,empty by default,in which case,logs are output to the stdout

examples/simple_example/JsonTestController.cc

@@ -13,6 +13,7 @@ void JsonTestController::asyncHandleHttpRequest(
         Json::Value user;
         user["id"] = i;
         user["name"] = "none";
+        user["c_name"] = "张三";
         array.append(user);
     }
     json["rows"] = array;

lib/inc/drogon/HttpAppFramework.h

@@ -1058,12 +1058,28 @@ class HttpAppFramework : public trantor::NonCopyable
      */
     virtual orm::DbClientPtr getFastDbClient(
         const std::string &name = "default") = 0;
+
     /**
      * @brief Check if all database clients in the framework are available
      * (connect to the database successfully).
      */
     virtual bool areAllDbClientsAvailable() const noexcept = 0;
 
+    /**
+     * @brief This method is to enable or disable the unicode escaping (\u) in
+     * the json string of HTTP responses or requests. it works (disable
+     * successfully) when the version of JsonCpp >= 1.9.3, the unicode escaping
+     * is enabled by default.
+     */
+    virtual HttpAppFramework &setUnicodeEscapingInJson(
+        bool enable) noexcept = 0;
+
+    /**
+     * @brief Check if the unicode escaping is used in the json string of HTTP
+     * requests and responses.
+     */
+    virtual bool isUnicodeEscapingUsedInJson() const noexcept = 0;
+
     /// Create a database client
     /**
      * @param dbType The database type is one of

lib/src/ConfigLoader.cc

@@ -367,6 +367,9 @@ static void loadApp(const Json::Value &app)
         }
     }
 #endif
+    auto unicodeEscaping =
+        app.get("enable_unicode_escaping_in_json", true).asBool();
+    drogon::app().setUnicodeEscapingInJson(unicodeEscaping);
     // log
     loadLogSetting(app["log"]);
     // run as daemon

lib/src/HttpAppFrameworkImpl.h

@@ -373,6 +373,18 @@ class HttpAppFrameworkImpl : public HttpAppFramework
         return running_;
     }
 
+    virtual HttpAppFramework &setUnicodeEscapingInJson(
+        bool enable) noexcept override
+    {
+        usingUnicodeEscaping_ = enable;
+        return *this;
+    }
+
+    virtual bool isUnicodeEscapingUsedInJson() const noexcept override
+    {
+        return usingUnicodeEscaping_;
+    }
+
     virtual trantor::EventLoop *getLoop() const override;
 
     virtual trantor::EventLoop *getIOLoop(size_t id) const override;
@@ -543,6 +555,7 @@ class HttpAppFrameworkImpl : public HttpAppFramework
     bool useSendfile_{true};
     bool useGzip_{true};
     bool useBrotli_{false};
+    bool usingUnicodeEscaping_{true};
     size_t clientMaxBodySize_{1024 * 1024};
     size_t clientMaxMemoryBodySize_{64 * 1024};
     size_t clientMaxWebSocketMessageSize_{128 * 1024};

lib/src/HttpRequestImpl.cc

@@ -465,6 +465,10 @@ HttpRequestPtr HttpRequest::newHttpJsonRequest(const Json::Value &data)
     std::call_once(once, []() {
         builder["commentStyle"] = "None";
         builder["indentation"] = "";
+        if (!app().isUnicodeEscapingUsedInJson())
+        {
+            builder["emitUTF8"] = true;
+        }
     });
     auto req = std::make_shared<HttpRequestImpl>(nullptr);
     req->setMethod(drogon::Get);

lib/src/HttpResponseImpl.cc

@@ -91,6 +91,10 @@ void HttpResponseImpl::generateBodyFromJson()
     std::call_once(once, []() {
         builder["commentStyle"] = "None";
         builder["indentation"] = "";
+        if (!app().isUnicodeEscapingUsedInJson())
+        {
+            builder["emitUTF8"] = true;
+        }
     });
     setBody(writeString(builder, *jsonPtr_));
 }