Allow parse_json to return a boolean result (#6884)

* Allow parse_json to return a boolean result

* Remove pass variable

esphome/components/json/json_util.cpp

@@ -62,7 +62,7 @@ std::string build_json(const json_build_t &f) {
   }
 }
 
-void parse_json(const std::string &data, const json_parse_t &f) {
+bool parse_json(const std::string &data, const json_parse_t &f) {
   // Here we are allocating 1.5 times the data size,
   // with the heap size minus 2kb to be safe if less than that
   // as we can not have a true dynamic sized document.
@@ -76,14 +76,13 @@ void parse_json(const std::string &data, const json_parse_t &f) {
 #elif defined(USE_LIBRETINY)
   const size_t free_heap = lt_heap_get_free();
 #endif
-  bool pass = false;
   size_t request_size = std::min(free_heap, (size_t) (data.size() * 1.5));
-  do {
+  while (true) {
     DynamicJsonDocument json_document(request_size);
     if (json_document.capacity() == 0) {
       ESP_LOGE(TAG, "Could not allocate memory for JSON document! Requested %u bytes, free heap: %u", request_size,
                free_heap);
-      return;
+      return false;
     }
     DeserializationError err = deserializeJson(json_document, data);
     json_document.shrinkToFit();
@@ -91,21 +90,21 @@ void parse_json(const std::string &data, const json_parse_t &f) {
     JsonObject root = json_document.as<JsonObject>();
 
     if (err == DeserializationError::Ok) {
-      pass = true;
+      return f(root);
-      f(root);
     } else if (err == DeserializationError::NoMemory) {
       if (request_size * 2 >= free_heap) {
         ESP_LOGE(TAG, "Can not allocate more memory for deserialization. Consider making source string smaller");
-        return;
+        return false;
       }
       ESP_LOGV(TAG, "Increasing memory allocation.");
       request_size *= 2;
       continue;
     } else {
       ESP_LOGE(TAG, "JSON parse error: %s", err.c_str());
-      return;
+      return false;
     }
-  } while (!pass);
+  };
+  return false;
 }
 
 }  // namespace json

esphome/components/json/json_util.h

@@ -14,7 +14,7 @@ namespace esphome {
 namespace json {
 
 /// Callback function typedef for parsing JsonObjects.
-using json_parse_t = std::function<void(JsonObject)>;
+using json_parse_t = std::function<bool(JsonObject)>;
 
 /// Callback function typedef for building JsonObjects.
 using json_build_t = std::function<void(JsonObject)>;
@@ -23,7 +23,7 @@ using json_build_t = std::function<void(JsonObject)>;
 std::string build_json(const json_build_t &f);
 
 /// Parse a JSON string and run the provided json parse function if it's valid.
-void parse_json(const std::string &data, const json_parse_t &f);
+bool parse_json(const std::string &data, const json_parse_t &f);
 
 }  // namespace json
 }  // namespace esphome

esphome/components/mqtt/mqtt_client.cpp

@@ -410,7 +410,10 @@ void MQTTClientComponent::subscribe(const std::string &topic, mqtt_callback_t ca
 
 void MQTTClientComponent::subscribe_json(const std::string &topic, const mqtt_json_callback_t &callback, uint8_t qos) {
   auto f = [callback](const std::string &topic, const std::string &payload) {
-    json::parse_json(payload, [topic, callback](JsonObject root) { callback(topic, root); });
+    json::parse_json(payload, [topic, callback](JsonObject root) -> bool {
+      callback(topic, root);
+      return true;
+    });
   };
   MQTTSubscription subscription{
       .topic = topic,