Help with assigning struct to class member with models

SafaAlfulaij

Hello.
First of all, sorry if this question may be stupid.

I am working on my first Qt app and came across a problem that I am not sure how to fix/name it.
Basically, I have a file that I use an external library to parse, and store the returned data class in a Storage class. This class is used by one of my models.
The issue is, I am not sure how to init the returned class to be a class member. Since the model is used, it request the rowCount before even I get anything assigned correctly, which causes a crash sometimes (maybe because of pointers and memory violation) in <vector> std library.

I apologize again if this is a stupid question, or even not a Qt specific question.
Thanks.

Minimal concept code:

// external library
struct FileData{
    // etc etc
    std::map<std::string, std::string> styles;
    std::vector<FileEvent> events;
};


// The Storage class for getting/setting/etc
class Storage : public QObject
{
public:
    Storage();

    bool loadFile(const QString& filePath) { // called by mainWindow
        FileParser fileParser; // external library's function
        // do file parse checking
        if (ok) {
            m_filePath = filePath;
            m_data = fileParser.data(); // data function returens a const struct FileData
            return true;
        }
        return false;
    }

    int eventCount() {
        return static_cast<int>(m_data->events.size());
    }

    FileEvent eventObj(int num);

private:
    QString m_filePath;
    FileData *m_data; // external
};


// The model to be used in Views and to work with the data
class EventsModel : public QAbstractTableModel
{
    Q_OBJECT

public:
    explicit EventsModel(QObject *parent = nullptr);

    void setStorage(Storage *storage) {
        beginResetModel();
        m_storage = storage;
        endResetModel();
    }

    int rowCount(const QModelIndex &parent = QModelIndex()) const override {
        return m_storage->eventCount();
    }

    // columnCount and data and headerData etc.

private:
    Storage *m_storage;
};

VRonin

in the constructor add m_storage(nullptr) to the initialiser list and change rowCount to:

int rowCount(const QModelIndex &parent = QModelIndex()) const override {
        return m_storage ? m_storage->eventCount() : 0;
    }