Merge branch 'v1.3.0' into better_provider_interface

azure-pipelines.yml

@@ -4,11 +4,11 @@
 # https://aka.ms/yaml
 
 jobs:
-- job: ubuntu_16_04_mem_pool_on
-  displayName: 'Build - Ubuntu 16.04 - With Memory Pool'
+- job: ubuntu_20_04_mem_pool_on
+  displayName: 'Build - Ubuntu 20.04 - With Memory Pool'
   continueOnError: false
   pool:
-    vmImage: 'Ubuntu 16.04'
+    vmImage: 'ubuntu-20.04'
   workspace:
     clean: all
   steps:
@@ -25,11 +25,11 @@ jobs:
       displayName: 'Test'
       workingDirectory: build
 
-- job: ubuntu_16_04_mem_pool_off
-  displayName: 'Build - Ubuntu 16.04 - No Memory Pool'
+- job: ubuntu_20_04_mem_pool_off
+  displayName: 'Build - Ubuntu 20.04 - No Memory Pool'
   continueOnError: false
   pool:
-    vmImage: 'Ubuntu 16.04'
+    vmImage: 'ubuntu-20.04'
   workspace:
     clean: all
   steps:

changelog/1.3.0.md

@@ -14,6 +14,7 @@ Contents:
 - [Response::getBody()](#responsegetbody)
 - [data::stream::FIFOStream](#datastreamfifostream)
 - [data::stream::BufferedInputStream](#datastreambufferedinputstream)
+- [oatpp::parser::json::mapping::Serializer::Config::alwaysIncludeRequired](#oatppparserjsonmappingSerializerConfigalwaysIncludeRequired)
 
 
 ## The New oatpp::String
@@ -199,7 +200,8 @@ ENDPOINT("GET", "videos/{videoId}", getVideoById,
 
 ## Response::getBody()
 
-`oatpp::web::protocol::http::outgoing::Response` has a new method `getBody()` to retreive the body of the response. This is handy for response interceptors.
+`oatpp::web::protocol::http::outgoing::Response` has a new method `getBody()` to retreive the body of the response.
+This is handy for response interceptors.
 
 
 ## data::stream::FIFOStream
@@ -223,3 +225,33 @@ You need to implement your own locking.
 [`BufferedInputStream`](https://oatpp.io/api/latest/oatpp/core/data/stream/Stream/#bufferedinputstream) which unifies
 the bufferd-stream-interface all existing buffered streams (`InputStreamBufferedProxy`, `BufferInputStream`,
 `FIFOStream`) to allow for generalisation.
+
+## oatpp::parser::json::mapping::Serializer::Config::alwaysIncludeRequired
+
+If `oatpp::parser::json::mapping::Serializer::Config::includeNullFields == false` there might still be the requirement
+to include some fields even if they are `nullptr`, because they are required by the deserializing end.
+
+Consider the following DTO and endpoint-snippet. 
+```c++
+class StatusDto : public oatpp::DTO {
+  DTO_INIT(StatusDto, DTO)
+  DTO_FIELD_INFO(status) {
+    info->required = true;
+  }
+  DTO_FIELD(String, status);
+  DTO_FIELD(Int32, code);
+  DTO_FIELD(String, message);
+};
+
+// endpoint code:
+ENDPOINT("GET", "/status", status) {
+    auto dto = StatusDto::createShared();
+    dto->code = 200;
+    return createDtoResponse(Status::CODE_200, dto);
+}
+```
+With a serializer with its config set to `Serializer::Config::includeNullFields = false`, the snippet would just yield `{"code":200}`.
+
+However, `status` is a required field.
+Now, one can set `Serializer::Config::alwaysIncludeRequired = true`.
+With `alwaysIncludeRequired == true`, the same snippet would yield `{"status":null,"code":200}`, even with `includeNullFields == false`.

src/oatpp/parser/json/mapping/Serializer.hpp

@@ -75,6 +75,11 @@ public:
      */
     bool alwaysIncludeRequired = false;
 
+    /**
+     * Always include array or map elements, even if their value is `nullptr`.
+     */
+    bool alwaysIncludeNullCollectionElements = false;
+
     /**
      * If `true` - insert string `"<unknown-type>"` in json field value in case unknown field found.
      * Fail if `false`.
@@ -142,7 +147,7 @@ private:
     bool first = true;
 
     for(auto& value : *list) {
-      if(value || serializer->getConfig()->includeNullFields) {
+      if(value || serializer->getConfig()->includeNullFields || serializer->getConfig()->alwaysIncludeNullCollectionElements) {
         (first) ? first = false : stream->writeSimple(",", 1);
         serializer->serialize(stream, value);
       }
@@ -167,7 +172,7 @@ private:
 
     for(auto& pair : *map) {
       const auto& value = pair.second;
-      if(value || serializer->m_config->includeNullFields) {
+      if(value || serializer->m_config->includeNullFields || serializer->m_config->alwaysIncludeNullCollectionElements) {
         (first) ? first = false : stream->writeSimple(",", 1);
         const auto& key = pair.first;
         serializeString(stream, key->data(), key->size(), serializer->m_config->escapeFlags);