Problem with my C++ library that uses a interface class

hi,i 'm creating a C++ library that inherits from an interface,but i have met some troubles during runtime.

it is my Interface class

Code:

---

#ifndef TABLEMANAGERINTERFACE_H
#define TABLEMANAGERINTERFACE_H
 
#include<QtPlugin>
 
#include <QtSql/QSqlRecord>
#include <QtSql/QSqlTableModel>
#include <QtSql/QSqlDatabase>
 
class TableManagerInterface
{
 
  private:
 
    enum TypeModels { ReadOnlyModel,ReadWriteModel,RelationnalModel};
public:
    virtual ~TableManagerInterface() {}
 
    virtual void setDatabase(const QSqlDatabase &database)=0;
    virtual void setTable(const QString &tablename)=0;
    virtual void select(const QString &filter=0);
    virtual void insertRecord(const QSqlRecord &record)=0;
    //virtual void editRecord(const QSqlRecord &record) =0;
    // virtual void deleteRecord(const QSqlRecord &record) =0;
 
 
};
 
QT_BEGIN_NAMESPACE
 
Q_DECLARE_INTERFACE(TableManagerInterface,
                    "com.MaxSoft.Plugin.TableManagerInterface/1.0")
 
QT_END_NAMESPACE
 
#endif

---

now the defintion of my library class

ItableManager.h

Code:

---

#ifndef ITABLEMANAGER_H
#define ITABLEMANAGER_H
 
#include "ITableManager_global.h"
#include <QtGui/QStylePlugin>
#include<QtSql>
#include "interface/TableManagerInterface.h"
 
 
class ITABLEMANAGERSHARED_EXPORT ITableManager :public QObject,public TableManagerInterface
{
     Q_OBJECT
     Q_INTERFACES(TableManagerInterface)
 
public:
    ITableManager();
    virtual ~ITableManager() {}
 
private:
    QSqlDatabase db;
    QSqlTableModel *model;
    QMap<int,QString>  mapKey;
public:
    void setDatabase(const QSqlDatabase &database);
    void setTable(const QString &tablename);
    void setPrimaryKeys(QMap<int, QString> map);
    void select(const QString &filter=0);
    QSqlRecord  record() const;
    void insertRecord(const QSqlRecord &record);
 
signals:
 
public slots:
 
 
 
};
 
#endif // ITABLEMANAGER_H

---

ITableManager.cpp

Code:

---

#include "itablemanager.h"
#include<QMessageBox>
 
 
ITableManager::ITableManager()
{
 
}
 
 
/*!
 Cette méthode permet de récupérer une instance de laconnexion
  à  une base de donnée
*/
void ITableManager::setDatabase(const QSqlDatabase &database)
{
  this->db=database;
}
 
/*!
 
informe sur la table et ses champs
  */
void ITableManager::setTable(const QString &tablename)
{
        model= new QSqlTableModel(0,this->db);
        model->setTable(tablename);
}
 
/*!
  charge le model avec les lignes
*/
void ITableManager::select(const QString &filter)
{
    model->setFilter(filter);
     if( !model->select() )
         qDebug()<<" Lignes non chargées";
}
 
/*!
  retourne une enregistrement contenant les infos à 
  propos des colonnes(champs) de la table
  */
QSqlRecord ITableManager::record() const
{
     return model->record();
}
 
/*!
  spécifie les clés primaires et leurs types
  */
 
void ITableManager::setPrimaryKeys(QMap<int, QString> map)
{
    mapKey = map;
}
 
/*!
 
 */
 
void ITableManager::insertRecord(const QSqlRecord &record)
{
 
    //on verifie si la clé existe
    QString filter="WHERE ";
 
    QMapIterator<int,QString> i(mapKey);
    while (i.hasNext()) {
           i.next();
          // cout << i.key() << ": " << i.value() << endl;
           if( i.value()=="int"){
 
               filter +=  record.fieldName(i.key()) + "=" + record.value(i.key()).toInt()+ " ";
           }
           else if (i.value()=="String") {
 
               filter += record.fieldName(i.key()) + "='" + record.value(i.key()).toString() +"' ";
           }
           else if (i.value()=="Date") {
               filter += record.fieldName(i.key()) + "='"+record.value(i.key()).toDate().toString("dd/MM/yyyy")+"' ";
 
           }
           else if (i.value()=="Double") {
               filter += record.fieldName(i.key()) + "=" +record.value(i.key()).toDouble() + " ";
 
           }
           if( i.hasNext())
               filter +=" AND ";
    }
 
    this->select(filter);
 
    if (model->rowCount() != 0)
         QMessageBox::warning(0,tr("Erreur Insertion"),tr("Présence de doublons"));
    else{
 
        if( model->insertRecord(-1,record) )
            QMessageBox::information(0,tr("Insertion"),tr("Enregistré"));
        else{
 
            QMessageBox::critical(0,tr("Erreur Insertion"),tr("Echec de L'enregistrement! <br> "
                                                              "Vérifiez les valeurs.."));
            qDebug()<< model->lastError().text();
        }
    }
 
 
}
 
Q_EXPORT_PLUGIN2(ITableManagerPlugin,ITableManager)

---

my ITableManager.pro

Code:

---

QT       += sql
 
TARGET = ITableManagerPlugin
TEMPLATE = lib
 
DEFINES += ITABLEMANAGER_LIBRARY
 
SOURCES += itablemanager.cpp
 
INCLUDEPATH +=interface/
 
HEADERS += itablemanager.h\
        ITableManager_global.h\
 
 
DESTDIR =../lib

---

so ,when i compile my program, i'm getting following errors in my application output pane

debug\tablemanagerplugin.o:-1: In function `TableManagerInterface':
TableManagerInterface.h:12: error: undefined reference to `vtable for TableManagerInterface'
debug\tablemanagerplugin.o:-1: In function `TableManagerPlugin':
tablemanagerplugin.h:8: error: undefined reference to `TableManagerInterface::~TableManagerInterface()'
:-1: error: collect2: ld returned 1 exit status


Someone can you tell me what the problem?
Thanks in advance

tablemanagerplugin.h:8: error: ...

where is this file?

TableManagerInterface.h:12 <-- This is an empty line. Are you sure that what you have posted matches EXACTLY what is compiled by you?

Code:

---

virtual void select(const QString &filter=0);

---

Method above is not virtual, I guess it's a mistake. Change it to pure virtual as below

Code:

---

virtual void select(const QString &filter)=0

---

and the error will go away.

Otherwise if you have an interface with at least one non-pure-virtual method move implementation of the destructor to a separate file (.cpp) and it will fix the error as well.

Here's a link that will tell you more about it.