Add support for volatile Facts/Parameters

src/FactSystem/Fact.cc

@@ -662,3 +662,13 @@ bool Fact::readOnly(void) const
         return false;
     }
 }
+
+bool Fact::volatileValue(void) const
+{
+    if (_metaData) {
+        return _metaData->volatileValue();
+    } else {
+        qWarning() << kMissingMetadata << name();
+        return false;
+    }
+}

src/FactSystem/Fact.h

@@ -71,6 +71,7 @@ public:
     Q_PROPERTY(bool         typeIsBool              READ typeIsBool                                         CONSTANT)
     Q_PROPERTY(bool         hasControl              READ hasControl                                         CONSTANT)
     Q_PROPERTY(bool         readOnly                READ readOnly                                           CONSTANT)
+    Q_PROPERTY(bool         volatileValue           READ volatileValue                                      CONSTANT)
 
     /// Convert and validate value
     ///     @param convertOnly true: validate type conversion only, false: validate against meta data as well
@@ -118,6 +119,7 @@ public:
     bool            typeIsBool              (void) const { return type() == FactMetaData::valueTypeBool; }
     bool            hasControl              (void) const;
     bool            readOnly                (void) const;
+    bool            volatileValue            (void) const;
 
     /// Returns the values as a string with full 18 digit precision if float/double.
     QString rawValueStringFullPrecision(void) const;

src/FactSystem/FactMetaData.cc

@@ -96,6 +96,7 @@ FactMetaData::FactMetaData(QObject* parent)
     , _increment            (std::numeric_limits<double>::quiet_NaN())
     , _hasControl           (true)
     , _readOnly             (false)
+    , _volatile             (false)
 {
 
 }
@@ -118,6 +119,7 @@ FactMetaData::FactMetaData(ValueType_t type, QObject* parent)
     , _increment            (std::numeric_limits<double>::quiet_NaN())
     , _hasControl           (true)
     , _readOnly             (false)
+    , _volatile             (false)
 {
 
 }
@@ -147,6 +149,7 @@ FactMetaData::FactMetaData(ValueType_t type, const QString name, QObject* parent
     , _increment            (std::numeric_limits<double>::quiet_NaN())
     , _hasControl           (true)
     , _readOnly             (false)
+    , _volatile             (false)
 {
 
 }
@@ -178,6 +181,7 @@ const FactMetaData& FactMetaData::operator=(const FactMetaData& other)
     _increment              = other._increment;
     _hasControl             = other._hasControl;
     _readOnly               = other._readOnly;
+    _volatile               = other._volatile;
     return *this;
 }
 
@@ -1128,3 +1132,11 @@ QVariant FactMetaData::cookedMin(void) const
         return cookedMin;
     }
 }
+
+void FactMetaData::setVolatileValue(bool bValue)
+{
+    _volatile = bValue;
+    if (_volatile) {
+        _readOnly = true;
+    }
+}

src/FactSystem/FactMetaData.h

@@ -101,6 +101,7 @@ public:
     bool            rebootRequired          (void) const { return _rebootRequired; }
     bool            hasControl              (void) const { return _hasControl; }
     bool            readOnly                (void) const { return _readOnly; }
+    bool            volatileValue           (void) const { return _volatile; }
 
     /// Amount to increment value when used in controls such as spin button or slider with detents.
     /// NaN for no increment available.
@@ -131,6 +132,7 @@ public:
     void setIncrement       (double increment)                  { _increment = increment; }
     void setHasControl      (bool bValue)                       { _hasControl = bValue; }
     void setReadOnly        (bool bValue)                       { _readOnly = bValue; }
+    void setVolatileValue   (bool bValue);
 
     void setTranslators(Translator rawTranslator, Translator cookedTranslator);
 
@@ -239,6 +241,7 @@ private:
     double          _increment;
     bool            _hasControl;
     bool            _readOnly;
+    bool            _volatile;
 
     // Exact conversion constants
     static const struct UnitConsts_s {

src/FactSystem/ParameterManager.cc

@@ -7,10 +7,6 @@
  *
  ****************************************************************************/
 
-
-/// @file
-///     @author Don Gagne <don@thegagnes.com>
-
 #include "ParameterManager.h"
 #include "QGCApplication.h"
 #include "QGCLoggingCategory.h"
@@ -27,9 +23,8 @@
 #include <QJsonArray>
 
 /* types for local parameter cache */
-typedef QPair<int, QVariant> ParamTypeVal;
-typedef QPair<QString, ParamTypeVal> NamedParam;
-typedef QMap<int, NamedParam> MapID2NamedParam;
+typedef QPair<int /* FactMetaData::ValueType_t */, QVariant /* Fact::rawValue */> ParamTypeVal;
+typedef QMap<QString /* parameter name */, ParamTypeVal> CacheMapName2ParamTypeVal;
 
 QGC_LOGGING_CATEGORY(ParameterManagerVerbose1Log, "ParameterManagerVerbose1Log")
 QGC_LOGGING_CATEGORY(ParameterManagerVerbose2Log, "ParameterManagerVerbose2Log")
@@ -43,25 +38,26 @@ const char* ParameterManager::_jsonParamNameKey =           "name";
 const char* ParameterManager::_jsonParamValueKey =          "value";
 
 ParameterManager::ParameterManager(Vehicle* vehicle)
-    : QObject(vehicle)
-    , _vehicle(vehicle)
-    , _mavlink(NULL)
-    , _loadProgress(0.0)
-    , _parametersReady(false)
-    , _missingParameters(false)
-    , _initialLoadComplete(false)
-    , _waitingForDefaultComponent(false)
-    , _saveRequired(false)
-    , _logReplay(vehicle->priorityLink() && vehicle->priorityLink()->isLogReplay())
-    , _parameterSetMajorVersion(-1)
-    , _parameterMetaData(NULL)
-    , _prevWaitingReadParamIndexCount(0)
-    , _prevWaitingReadParamNameCount(0)
-    , _prevWaitingWriteParamNameCount(0)
-    , _initialRequestRetryCount(0)
-    , _disableAllRetries(false)
-    , _indexBatchQueueActive(false)
-    , _totalParamCount(0)
+    : QObject                           (vehicle)
+    , _vehicle                          (vehicle)
+    , _mavlink                          (NULL)
+    , _loadProgress                     (0.0)
+    , _parametersReady                  (false)
+    , _missingParameters                (false)
+    , _initialLoadComplete              (false)
+    , _waitingForDefaultComponent       (false)
+    , _saveRequired                     (false)
+    , _metaDataAddedToFacts             (false)
+    , _logReplay                        (vehicle->priorityLink() && vehicle->priorityLink()->isLogReplay())
+    , _parameterSetMajorVersion         (-1)
+    , _parameterMetaData                (NULL)
+    , _prevWaitingReadParamIndexCount   (0)
+    , _prevWaitingReadParamNameCount    (0)
+    , _prevWaitingWriteParamNameCount   (0)
+    , _initialRequestRetryCount         (0)
+    , _disableAllRetries                (false)
+    , _indexBatchQueueActive            (false)
+    , _totalParamCount                  (0)
 {
     _versionParam = vehicle->firmwarePlugin()->getVersionParam();
 
@@ -137,10 +133,12 @@ void ParameterManager::_parameterUpdate(int vehicleId, int componentId, QString
     }
 #endif
 
-    if (_vehicle->px4Firmware() && parameterName == "_HASH_CHECK" && !_logReplay) {
-        /* we received a cache hash, potentially load from cache */
-        _tryCacheHashLoad(vehicleId, componentId, value);
-        return;
+	if (_vehicle->px4Firmware() && parameterName == "_HASH_CHECK") {
+    	if (!_initialLoadComplete && !_logReplay) {
+        	/* we received a cache hash, potentially load from cache */
+        	_tryCacheHashLoad(vehicleId, componentId, value);
+		}
+		return;
     }
 
     _initialRequestTimeoutTimer.stop();
@@ -154,8 +152,6 @@ void ParameterManager::_parameterUpdate(int vehicleId, int componentId, QString
         _totalParamCount += parameterCount;
     }
 
-    _mapParameterId2Name[componentId][parameterId] = parameterName;
-
     // If we've never seen this component id before, setup the wait lists.
     if (!_waitingReadParamIndexMap.contains(componentId)) {
         // Add all indices to the wait list, parameter index is 0-based
@@ -735,19 +731,18 @@ void ParameterManager::_writeParameterRaw(int componentId, const QString& paramN
 
 void ParameterManager::_writeLocalParamCache(int vehicleId, int componentId)
 {
-    MapID2NamedParam cache_map;
+    CacheMapName2ParamTypeVal cacheMap;
 
-    foreach(int id, _mapParameterId2Name[componentId].keys()) {
-        const QString name(_mapParameterId2Name[componentId][id]);
+    foreach(const QString& name, _mapParameterName2Variant[componentId].keys()) {
         const Fact *fact = _mapParameterName2Variant[componentId][name].value<Fact*>();
-        cache_map[id] = NamedParam(name, ParamTypeVal(fact->type(), fact->rawValue()));
+        cacheMap[name] = ParamTypeVal(fact->type(), fact->rawValue());
     }
 
-    QFile cache_file(parameterCacheFile(vehicleId, componentId));
-    cache_file.open(QIODevice::WriteOnly | QIODevice::Truncate);
+    QFile cacheFile(parameterCacheFile(vehicleId, componentId));
+    cacheFile.open(QIODevice::WriteOnly | QIODevice::Truncate);
 
-    QDataStream ds(&cache_file);
-    ds << cache_map;
+    QDataStream ds(&cacheFile);
+    ds << cacheMap;
 }
 
 QDir ParameterManager::parameterCacheDir()
@@ -758,46 +753,70 @@ QDir ParameterManager::parameterCacheDir()
 
 QString ParameterManager::parameterCacheFile(int vehicleId, int componentId)
 {
-    return parameterCacheDir().filePath(QString("%1_%2").arg(vehicleId).arg(componentId));
+    return parameterCacheDir().filePath(QString("%1_%2.v2").arg(vehicleId).arg(componentId));
 }
 
 void ParameterManager::_tryCacheHashLoad(int vehicleId, int componentId, QVariant hash_value)
 {
+    qCInfo(ParameterManagerLog) << "Attemping load from cache";
+
     uint32_t crc32_value = 0;
     /* The datastructure of the cache table */
-    MapID2NamedParam cache_map;
-    QFile cache_file(parameterCacheFile(vehicleId, componentId));
-    if (!cache_file.exists()) {
+    CacheMapName2ParamTypeVal cacheMap;
+    QFile cacheFile(parameterCacheFile(vehicleId, componentId));
+    if (!cacheFile.exists()) {
         /* no local cache, just wait for them to come in*/
         return;
     }
-    cache_file.open(QIODevice::ReadOnly);
+    cacheFile.open(QIODevice::ReadOnly);
 
     /* Deserialize the parameter cache table */
-    QDataStream ds(&cache_file);
-    ds >> cache_map;
+    QDataStream ds(&cacheFile);
+    ds >> cacheMap;
+
+    // Load parameter meta data for the version number stored in cache.
+    // We need meta data so we have access to the volatile bit
+    if (cacheMap.contains(_versionParam)) {
+        _parameterSetMajorVersion = cacheMap[_versionParam].second.toInt();
+    }
+    _loadMetaData();
 
     /* compute the crc of the local cache to check against the remote */
 
-    foreach(int id, cache_map.keys()) {
-        const QString name(cache_map[id].first);
-        const void *vdat = cache_map[id].second.second.constData();
-        const FactMetaData::ValueType_t fact_type = static_cast<FactMetaData::ValueType_t>(cache_map[id].second.first);
-        crc32_value = QGC::crc32((const uint8_t *)qPrintable(name), name.length(),  crc32_value);
-        crc32_value = QGC::crc32((const uint8_t *)vdat, FactMetaData::typeToSize(fact_type), crc32_value);
+    FirmwarePlugin* firmwarePlugin = _vehicle->firmwarePlugin();
+    foreach (const QString& name, cacheMap.keys()) {
+        bool volatileValue = false;
+
+        FactMetaData* metaData = firmwarePlugin->getMetaDataForFact(_parameterMetaData, name, _vehicle->vehicleType());
+        if (metaData) {
+            volatileValue = metaData->volatileValue();
+        }
+
+        if (volatileValue) {
+            // Does not take part in CRC
+            qCDebug(ParameterManagerLog) << "Volatile parameter" << name;
+        } else {
+            const ParamTypeVal& paramTypeVal = cacheMap[name];
+            const void *vdat = paramTypeVal.second.constData();
+            const FactMetaData::ValueType_t fact_type = static_cast<FactMetaData::ValueType_t>(paramTypeVal.first);
+            crc32_value = QGC::crc32((const uint8_t *)qPrintable(name), name.length(),  crc32_value);
+            crc32_value = QGC::crc32((const uint8_t *)vdat, FactMetaData::typeToSize(fact_type), crc32_value);
+        }
     }
 
+    /* if the two param set hashes match, just load from the disk */
     if (crc32_value == hash_value.toUInt()) {
-        qCInfo(ParameterManagerLog) << "Parameters loaded from cache" << qPrintable(QFileInfo(cache_file).absoluteFilePath());
-        /* if the two param set hashes match, just load from the disk */
-        int count = cache_map.count();
-        foreach(int id, cache_map.keys()) {
-            const QString &name = cache_map[id].first;
-            const QVariant &value = cache_map[id].second.second;
-            const FactMetaData::ValueType_t fact_type = static_cast<FactMetaData::ValueType_t>(cache_map[id].second.first);
+        qCInfo(ParameterManagerLog) << "Parameters loaded from cache" << qPrintable(QFileInfo(cacheFile).absoluteFilePath());
+
+        int count = cacheMap.count();
+        int index = 0;
+        foreach (const QString& name, cacheMap.keys()) {
+            const ParamTypeVal& paramTypeVal = cacheMap[name];
+            const FactMetaData::ValueType_t fact_type = static_cast<FactMetaData::ValueType_t>(paramTypeVal.first);
             const int mavType = _factTypeToMavType(fact_type);
-            _parameterUpdate(vehicleId, componentId, name, count, id, mavType, value);
+            _parameterUpdate(vehicleId, componentId, name, count, index++, mavType, paramTypeVal.second);
         }
+
         // Return the hash value to notify we don't want any more updates
         mavlink_param_set_t     p;
         mavlink_param_union_t   union_value;
@@ -836,7 +855,10 @@ void ParameterManager::_tryCacheHashLoad(int vehicleId, int componentId, QVarian
 
         ani->start(QAbstractAnimation::DeleteWhenStopped);
     } else {
-        qCInfo(ParameterManagerLog) << "Parameters cache match failed" << qPrintable(QFileInfo(cache_file).absoluteFilePath());
+        // Cache parameter version may differ from vehicle parameter version so we can't trust information loaded from cache parameter version number
+        _parameterSetMajorVersion = -1;
+        _clearMetaData();
+        qCInfo(ParameterManagerLog) << "Parameters cache match failed" << qPrintable(QFileInfo(cacheFile).absoluteFilePath());
     }
 }
 
@@ -993,7 +1015,15 @@ FactMetaData::ValueType_t ParameterManager::_mavTypeToFactType(MAV_PARAM_TYPE ma
     }
 }
 
-void ParameterManager::_addMetaDataToDefaultComponent(void)
+void ParameterManager::_clearMetaData(void)
+{
+    if (_parameterMetaData) {
+        _parameterMetaData->deleteLater();
+        _parameterMetaData = NULL;
+    }
+}
+
+void ParameterManager::_loadMetaData(void)
 {
     if (_parameterMetaData) {
         return;
@@ -1004,9 +1034,18 @@ void ParameterManager::_addMetaDataToDefaultComponent(void)
 
     // Load best parameter meta data set
     metaDataFile = parameterMetaDataFile(_vehicle, _vehicle->firmwareType(), _parameterSetMajorVersion, majorVersion, minorVersion);
-    qCDebug(ParameterManagerLog) << "Adding meta data to Vehicle file:major:minor" << metaDataFile << majorVersion << minorVersion;
-
+    qCDebug(ParameterManagerLog) << "Loading meta data file:major:minor" << metaDataFile << majorVersion << minorVersion;
     _parameterMetaData = _vehicle->firmwarePlugin()->loadParameterMetaData(metaDataFile);
+}
+
+void ParameterManager::_addMetaDataToDefaultComponent(void)
+{
+    _loadMetaData();
+
+    if (_metaDataAddedToFacts) {
+        return;
+    }
+    _metaDataAddedToFacts = true;
 
     // Loop over all parameters in default component adding meta data
     QVariantMap& factMap = _mapParameterName2Variant[_vehicle->defaultComponentId()];

src/FactSystem/ParameterManager.h

@@ -142,6 +142,8 @@ private:
     void _writeParameterRaw(int componentId, const QString& paramName, const QVariant& value);
     void _writeLocalParamCache(int vehicleId, int componentId);
     void _tryCacheHashLoad(int vehicleId, int componentId, QVariant hash_value);
+    void _loadMetaData(void);
+    void _clearMetaData(void);
     void _addMetaDataToDefaultComponent(void);
     QString _remapParamNameToVersion(const QString& paramName);
     void _loadOfflineEditingParams(void);
@@ -158,8 +160,6 @@ private:
     /// Second mapping is parameter name, to Fact* in QVariant
     QMap<int, QVariantMap>            _mapParameterName2Variant;
 
-    QMap<int, QMap<int, QString> >    _mapParameterId2Name;
-
     // Category map of default component parameters
     QMap<QString /* category */, QMap<QString /* group */, QStringList /* parameter names */> > _categoryMap;
     
@@ -169,6 +169,7 @@ private:
     bool        _initialLoadComplete;           ///< true: Initial load of all parameters complete, whether successful or not
     bool        _waitingForDefaultComponent;    ///< true: last chance wait for default component params
     bool        _saveRequired;                  ///< true: _saveToEEPROM should be called
+    bool        _metaDataAddedToFacts;          ///< true: FactMetaData has been adde to the default component facts
     bool        _logReplay;                     ///< true: running with log replay link
     QString     _versionParam;                  ///< Parameter which contains parameter set version
     int         _parameterSetMajorVersion;      ///< Version for parameter set, -1 if not known

src/FirmwarePlugin/FirmwarePlugin.h

@@ -218,6 +218,11 @@ public:
     ///         call deleteParameterMetaData when no longer needed.
     virtual QObject* loadParameterMetaData(const QString& metaDataFile) { Q_UNUSED(metaDataFile); return NULL; }
 
+    /// Returns the FactMetaData associated with the parameter name
+    ///     @param opaqueParameterMetaData Opaque pointer returned from loadParameterMetaData
+    ///     @param name Parameter name
+    virtual FactMetaData* getMetaDataForFact(QObject* parameterMetaData, const QString& name, MAV_TYPE vehicleType) { Q_UNUSED(parameterMetaData); Q_UNUSED(name); Q_UNUSED(vehicleType); return NULL; }
+
     /// Adds the parameter meta data to the Fact
     ///     @param opaqueParameterMetaData Opaque pointer returned from loadParameterMetaData
     virtual void addMetaDataToFact(QObject* parameterMetaData, Fact* fact, MAV_TYPE vehicleType) { Q_UNUSED(parameterMetaData); Q_UNUSED(fact); Q_UNUSED(vehicleType); return; }

src/FirmwarePlugin/PX4/PX4FirmwarePlugin.cc

@@ -247,6 +247,19 @@ bool PX4FirmwarePlugin::sendHomePositionToVehicle(void)
     return false;
 }
 
+FactMetaData* PX4FirmwarePlugin::getMetaDataForFact(QObject* parameterMetaData, const QString& name, MAV_TYPE vehicleType)
+{
+    PX4ParameterMetaData* px4MetaData = qobject_cast<PX4ParameterMetaData*>(parameterMetaData);
+
+    if (px4MetaData) {
+        return px4MetaData->getMetaDataForFact(name, vehicleType);
+    } else {
+        qWarning() << "Internal error: pointer passed to PX4FirmwarePlugin::getMetaDataForFact not PX4ParameterMetaData";
+    }
+
+    return NULL;
+}
+
 void PX4FirmwarePlugin::addMetaDataToFact(QObject* parameterMetaData, Fact* fact, MAV_TYPE vehicleType)
 {
     PX4ParameterMetaData* px4MetaData = qobject_cast<PX4ParameterMetaData*>(parameterMetaData);
@@ -258,6 +271,11 @@ void PX4FirmwarePlugin::addMetaDataToFact(QObject* parameterMetaData, Fact* fact
     }
 }
 
+void PX4FirmwarePlugin::getParameterMetaDataVersionInfo(const QString& metaDataFile, int& majorVersion, int& minorVersion)
+{
+    return PX4ParameterMetaData::getParameterMetaDataVersionInfo(metaDataFile, majorVersion, minorVersion);
+}
+
 QList<MAV_CMD> PX4FirmwarePlugin::supportedMissionCommands(void)
 {
     QList<MAV_CMD> list;
@@ -571,5 +589,3 @@ QGCCameraControl* PX4FirmwarePlugin::createCameraControl(const mavlink_camera_in
 {
     return new QGCCameraControl(info, vehicle, compID, parent);
 }
-
-

src/FirmwarePlugin/PX4/PX4FirmwarePlugin.h

@@ -56,10 +56,11 @@ public:
     void                initializeVehicle               (Vehicle* vehicle) override;
     bool                sendHomePositionToVehicle       (void) override;
     void                addMetaDataToFact               (QObject* parameterMetaData, Fact* fact, MAV_TYPE vehicleType) override;
+    FactMetaData*       getMetaDataForFact              (QObject* parameterMetaData, const QString& name, MAV_TYPE vehicleType) override;
     QString             missionCommandOverrides         (MAV_TYPE vehicleType) const override;
     QString             getVersionParam                 (void) override { return QString("SYS_PARAM_VER"); }
     QString             internalParameterMetaDataFile   (Vehicle* vehicle) override { Q_UNUSED(vehicle); return QString(":/FirmwarePlugin/PX4/PX4ParameterFactMetaData.xml"); }
-    void                getParameterMetaDataVersionInfo (const QString& metaDataFile, int& majorVersion, int& minorVersion) override { PX4ParameterMetaData::getParameterMetaDataVersionInfo(metaDataFile, majorVersion, minorVersion); }
+    void                getParameterMetaDataVersionInfo (const QString& metaDataFile, int& majorVersion, int& minorVersion) override;
     QObject*            loadParameterMetaData           (const QString& metaDataFile) final;
     bool                adjustIncomingMavlinkMessage    (Vehicle* vehicle, mavlink_message_t* message) override;
     QString             offlineEditingParamFile(Vehicle* vehicle) override { Q_UNUSED(vehicle); return QStringLiteral(":/FirmwarePlugin/PX4/PX4.OfflineEditing.params"); }

src/FirmwarePlugin/PX4/PX4ParameterMetaData.cc

@@ -186,6 +186,20 @@ void PX4ParameterMetaData::loadParameterFactMetaDataFile(const QString& metaData
                     category = QStringLiteral("Standard");
                 }
 
+                bool volatileValue = false;
+                bool readOnly = false;
+                QString volatileStr = xml.attributes().value("volatile").toString();
+                if (volatileStr.compare(QStringLiteral("true")) == 0) {
+                    volatileValue = true;
+                    readOnly = true;
+                }
+                if (!volatileValue) {
+                    QString readOnlyStr = xml.attributes().value("readonly").toString();
+                    if (readOnlyStr.compare(QStringLiteral("true")) == 0) {
+                        readOnly = true;
+                    }
+                }
+
                 qCDebug(PX4ParameterMetaDataLog) << "Found parameter name:" << name << " type:" << type << " default:" << strDefault;
 
                 // Convert type from string to FactMetaData::ValueType_t
@@ -211,6 +225,8 @@ void PX4ParameterMetaData::loadParameterFactMetaDataFile(const QString& metaData
                     metaData->setName(name);
                     metaData->setCategory(category);
                     metaData->setGroup(factGroup);
+                    metaData->setReadOnly(readOnly);
+                    metaData->setVolatileValue(volatileValue);
                     
                     if (xml.attributes().hasAttribute("default") && !strDefault.isEmpty()) {
                         QVariant varDefault;
@@ -387,6 +403,17 @@ void PX4ParameterMetaData::loadParameterFactMetaDataFile(const QString& metaData
     }
 }
 
+FactMetaData* PX4ParameterMetaData::getMetaDataForFact(const QString& name, MAV_TYPE vehicleType)
+{
+    Q_UNUSED(vehicleType)
+
+    if (_mapParameterName2FactMetaData.contains(name)) {
+        return _mapParameterName2FactMetaData[name];
+    } else {
+        return NULL;
+    }
+}
+
 void PX4ParameterMetaData::addMetaDataToFact(Fact* fact, MAV_TYPE vehicleType)
 {
     Q_UNUSED(vehicleType)

src/FirmwarePlugin/PX4/PX4ParameterMetaData.h

@@ -33,8 +33,9 @@ class PX4ParameterMetaData : public QObject
 public:
     PX4ParameterMetaData(void);
 
-    void loadParameterFactMetaDataFile  (const QString& metaDataFile);
-    void addMetaDataToFact              (Fact* fact, MAV_TYPE vehicleType);
+    void            loadParameterFactMetaDataFile   (const QString& metaDataFile);
+    FactMetaData*   getMetaDataForFact              (const QString& name, MAV_TYPE vehicleType);
+    void            addMetaDataToFact               (Fact* fact, MAV_TYPE vehicleType);
 
     static void getParameterMetaDataVersionInfo(const QString& metaDataFile, int& majorVersion, int& minorVersion);