Improved plugin initialization. Added delete feature.

core/service.h

@@ -21,6 +21,10 @@ class Service
 public:
     Service() { }
 
+    explicit Service(const QString &pluginId) {
+        m_pluginId = pluginId;
+    }
+
     QList<QSharedPointer<T> > all() {
         odb::database *db = Context::instance().db();
 
@@ -69,6 +73,16 @@ public:
         return entity;
     }
 
+    void erase(QSharedPointer<T> entity) {
+        odb::database *db = Context::instance().db();
+
+        Q_ASSERT(db);
+
+        Transaction tx;
+        db->erase(entity);
+        tx.commit();
+    }
+
     void setPluginId(const QString &pluginId) {
         m_pluginId = pluginId;
     }