merge #2108

src/ESP32React/FSPersistence.h

@@ -0,0 +1,119 @@
+#ifndef FSPersistence_h
+#define FSPersistence_h
+
+#include "StatefulService.h"
+#include "FS.h"
+
+template <class T>
+class FSPersistence {
+  public:
+    FSPersistence(JsonStateReader<T> stateReader, JsonStateUpdater<T> stateUpdater, StatefulService<T> * statefulService, FS * fs, const char * filePath)
+        : _stateReader(stateReader)
+        , _stateUpdater(stateUpdater)
+        , _statefulService(statefulService)
+        , _fs(fs)
+        , _filePath(filePath)
+        , _updateHandlerId(0) {
+        enableUpdateHandler();
+    }
+
+    void readFromFS() {
+        File settingsFile = _fs->open(_filePath, "r");
+
+        if (settingsFile) {
+            JsonDocument         jsonDocument;
+            DeserializationError error = deserializeJson(jsonDocument, settingsFile);
+            if (error == DeserializationError::Ok && jsonDocument.is<JsonObject>()) {
+                JsonObject jsonObject = jsonDocument.as<JsonObject>();
+                _statefulService->updateWithoutPropagation(jsonObject, _stateUpdater);
+#if defined(EMSESP_DEBUG)
+                // Serial.println();
+                // Serial.printf("Reading settings from %s ", _filePath);
+                // serializeJson(jsonDocument, Serial);
+                // Serial.println();
+#endif
+                settingsFile.close();
+                return;
+            }
+            settingsFile.close();
+        }
+
+// If we reach here we have not been successful in loading the config,
+// hard-coded emergency defaults are now applied.
+#if defined(EMSESP_DEBUG)
+        // Serial.println();
+        // Serial.printf("Applying defaults to %s", _filePath);
+        // Serial.println();
+#endif
+        applyDefaults();
+        writeToFS(); // added to make sure the initial file is created
+    }
+
+    bool writeToFS() {
+        // create and populate a new json object
+        JsonDocument jsonDocument;
+        JsonObject   jsonObject = jsonDocument.to<JsonObject>();
+        _statefulService->read(jsonObject, _stateReader);
+
+        // make directories if required, for new IDF4.2 & LittleFS
+        String path(_filePath);
+        int    index = 0;
+        while ((index = path.indexOf('/', static_cast<unsigned int>(index) + 1)) != -1) {
+            String segment = path.substring(0, static_cast<unsigned int>(index));
+            if (!_fs->exists(segment)) {
+                _fs->mkdir(segment);
+            }
+        }
+
+        // serialize it to filesystem
+        File settingsFile = _fs->open(_filePath, "w");
+
+        // failed to open file, return false
+        if (!settingsFile || !jsonObject.size()) {
+            return false;
+        }
+
+        // serialize the data to the file
+#if defined(EMSESP_DEBUG)
+        // Serial.println();
+        // Serial.printf("Writing settings to %s ", _filePath);
+        // serializeJson(jsonDocument, Serial);
+        // Serial.println();
+#endif
+        serializeJson(jsonDocument, settingsFile);
+        settingsFile.close();
+        return true;
+    }
+
+    void disableUpdateHandler() {
+        if (_updateHandlerId) {
+            _statefulService->removeUpdateHandler(_updateHandlerId);
+            _updateHandlerId = 0;
+        }
+    }
+
+    void enableUpdateHandler() {
+        if (!_updateHandlerId) {
+            _updateHandlerId = _statefulService->addUpdateHandler([&] { writeToFS(); });
+        }
+    }
+
+  private:
+    JsonStateReader<T>   _stateReader;
+    JsonStateUpdater<T>  _stateUpdater;
+    StatefulService<T> * _statefulService;
+    FS *                 _fs;
+    const char *         _filePath;
+    update_handler_id_t  _updateHandlerId;
+
+  protected:
+    // We assume the updater supplies sensible defaults if an empty object
+    // is supplied, this virtual function allows that to be changed.
+    virtual void applyDefaults() {
+        JsonDocument jsonDocument;
+        JsonObject   jsonObject = jsonDocument.as<JsonObject>();
+        _statefulService->updateWithoutPropagation(jsonObject, _stateUpdater);
+    }
+};
+
+#endif