void connector_BeforeProcessing(object sender, DataActionProcessingEventArgs e)
        {
            if (string.IsNullOrEmpty(e.DataAction.Data[(TableField)"title"]))
                e.DataAction.SetInvalid("Book title cannot be empty!");

            if (string.IsNullOrEmpty(e.DataAction.Data[(TableField)"author"]))
                e.DataAction.SetInvalid("Book author cannot be empty!");
        }
 void connector_BeforeInsert(object sender, DataActionProcessingEventArgs e)
 {
     e.DataAction.Data.Add("create_date", Tools.ConvertToString(DateTime.Now));
 }
 void connector_BeforeInsert(object sender, DataActionProcessingEventArgs e)
 {
     if (!e.DataAction.Data.ContainsKey((TableField)"Name"))
         e.DataAction.Data.Add("Name", "");//Name field is mandatory in table Country
 }
 void connector_BeforeUpdate(object sender, DataActionProcessingEventArgs e)
 {
     if (e.DataAction.Data[(this.Connector as dhtmlxTreeConnector).NodeTextField] == "")
         e.DataAction.SetInvalid("File name cannot be empty!");
 }
 void connector_BeforeDataActionProcessing(object sender, DataActionProcessingEventArgs e)
 {
     e.DataAction.SetFailed("Operation denied!");
 }