protected virtual void OnCallingDataMethods(CallingDataMethodsEventArgs e)
{
CallingDataMethodsEventHandler handler = Events[EventCallingDataMethods] as CallingDataMethodsEventHandler;
if (handler != null)
{
handler(_owner.DataControl, e);
}
}
/// <devdoc>
/// Gets the IDataSource that this control is bound to, if any.
/// Because this method can be called directly by derived classes, it's virtual so data can be retrieved
/// from data sources that don't live on the page.
/// </devdoc>
protected virtual IDataSource GetDataSource()
{
if (!DesignMode && IsUsingModelBinders)
{
//Let the developer choose a custom ModelDataSource.
CreatingModelDataSourceEventArgs e = new CreatingModelDataSourceEventArgs();
OnCreatingModelDataSource(e);
if (e.ModelDataSource != null)
{
ModelDataSource = e.ModelDataSource;
}
//Update the properties of ModelDataSource so that it's ready for data-binding.
UpdateModelDataSourceProperties(ModelDataSource);
CallingDataMethodsEventHandler handler = Events[EventCallingDataMethods] as CallingDataMethodsEventHandler;
if (handler != null)
{
ModelDataSource.CallingDataMethods += handler;
}
return(ModelDataSource);
}
if (!DesignMode && _currentDataSourceValid && (_currentDataSource != null))
{
return(_currentDataSource);
}
IDataSource ds = null;
string dataSourceID = DataSourceID;
if (dataSourceID.Length != 0)
{
// Try to find a DataSource control with the ID specified in DataSourceID
Control control = DataBoundControlHelper.FindControl(this, dataSourceID);
if (control == null)
{
throw new HttpException(SR.GetString(SR.DataControl_DataSourceDoesntExist, ID, dataSourceID));
}
ds = control as IDataSource;
if (ds == null)
{
throw new HttpException(SR.GetString(SR.DataControl_DataSourceIDMustBeDataControl, ID, dataSourceID));
}
}
return(ds);
}
/// <devdoc>
/// Connects this data bound control to the appropriate DataSourceView
/// and hooks up the appropriate event listener for the
/// DataSourceViewChanged event. The return value is the new view (if
/// any) that was connected to. An exception is thrown if there is
/// a problem finding the requested view or data source.
/// </devdoc>
private DataSourceView ConnectToDataSourceView()
{
if (_currentViewValid && !DesignMode)
{
// If the current view is correct, there is no need to reconnect
return(_currentView);
}
// Disconnect from old view, if necessary
if ((_currentView != null) && (_currentViewIsFromDataSourceID))
{
// We only care about this event if we are bound through the DataSourceID property
_currentView.DataSourceViewChanged -= new EventHandler(OnDataSourceViewChanged);
}
// Connect to new view
IDataSource ds = null;
if (!DesignMode && IsUsingModelBinders)
{
if (DataSourceID.Length != 0 || DataSource != null)
{
throw new InvalidOperationException(SR.GetString(SR.DataControl_ItemType_MultipleDataSources, ID));
}
//Let the developer choose a custom ModelDataSource.
CreatingModelDataSourceEventArgs e = new CreatingModelDataSourceEventArgs();
OnCreatingModelDataSource(e);
if (e.ModelDataSource != null)
{
ModelDataSource = e.ModelDataSource;
}
//Update the properties of ModelDataSource so that it's ready for data-binding.
UpdateModelDataSourceProperties(ModelDataSource);
//Add the CallingDataMethodsEvent
CallingDataMethodsEventHandler handler = Events[EventCallingDataMethods] as CallingDataMethodsEventHandler;
if (handler != null)
{
ModelDataSource.CallingDataMethods += handler;
}
ds = ModelDataSource;
}
else
{
string dataSourceID = DataSourceID;
if (dataSourceID.Length != 0)
{
// Try to find a DataSource control with the ID specified in DataSourceID
Control control = DataBoundControlHelper.FindControl(this, dataSourceID);
if (control == null)
{
throw new HttpException(SR.GetString(SR.DataControl_DataSourceDoesntExist, ID, dataSourceID));
}
ds = control as IDataSource;
if (ds == null)
{
throw new HttpException(SR.GetString(SR.DataControl_DataSourceIDMustBeDataControl, ID, dataSourceID));
}
}
}
if (ds == null)
{
// DataSource control was not found, construct a temporary data source to wrap the data
ds = new ReadOnlyDataSource(DataSource, DataMember);
}
else
{
// Ensure that both DataSourceID as well as DataSource are not set at the same time
if (DataSource != null)
{
throw new InvalidOperationException(SR.GetString(SR.DataControl_MultipleDataSources, ID));
}
}
// IDataSource was found, extract the appropriate view and return it
DataSourceView newView = ds.GetView(DataMember);
if (newView == null)
{
throw new InvalidOperationException(SR.GetString(SR.DataControl_ViewNotFound, ID));
}
_currentViewIsFromDataSourceID = IsDataBindingAutomatic;
_currentView = newView;
if ((_currentView != null) && (_currentViewIsFromDataSourceID))
{
// We only care about this event if we are bound through the DataSourceID property
_currentView.DataSourceViewChanged += new EventHandler(OnDataSourceViewChanged);
}
_currentViewValid = true;
return(_currentView);
}
