public virtual void OnEmployeeSelected(BusinessEntities.Employee employee)
{
// We are still using Push based composition here, to show the usage of scoped regionmanagers.
// When an employee gets selected, we are creating a new instance of the EmployeeDetailsView and are pushing it in the region.
// this would be hard to do with the 'out of the box' functionality of the pull based composition, because we
// have a requirement where we want to push a view into the region at a specific point in time, and not when
// the region decides it needs to pull a view into it.
IRegion detailsRegion = regionManager.Regions[RegionNames.DetailsRegion];
object existingView = detailsRegion.GetView(employee.EmployeeId.ToString(CultureInfo.InvariantCulture));
// See if the view already exists in the region.
if (existingView == null)
{
// the view does not exist yet. Create it and push it into the region
IEmployeesDetailsPresenter detailsPresenter = this.container.Resolve <IEmployeesDetailsPresenter>();
detailsPresenter.SetSelectedEmployee(employee);
// the details view should receive it's own scoped region manager, therefore Add overload using 'true' (see notes below).
detailsRegion.Add(detailsPresenter.View, employee.EmployeeId.ToString(CultureInfo.InvariantCulture), true);
detailsRegion.Activate(detailsPresenter.View);
}
else
{
// The view already exists. Just show it.
detailsRegion.Activate(existingView);
}
//************************************************************************************************
// Note on using Scoped Regionmanagers:
// Scoped regionmanagers are used to have multiple instances of the same region in memory at the same time.
// Since a region gets registered with a regionmanager, the name has to be unique.
// In this example, we are keeping several instances of the EmployeeDetailsView in memory. Each view has it's own TabRegion,
// so each view needs it's own regionmanager. This is still hard to do with pull based composition.
//************************************************************************************************
//************************************************************************************************
// Note on Push based vs Pull based composition.
// Prism V2 is going to support both Push based (V1 style) and Pull based (New in V2) composition.
//
// In pull based composition, as soon as the region get's added to the visual tree, it will be populated with new instances of
// registered views. In Pull based composition, you get less control over when views are added (only on load of the region)
// but this allows for an easier programming model.
//
// In push based composition, you have to write some code that, at a certain point in time, finds a region that's already
// created (might not be visible yet) and adds views to it. Using Push based composition, you have more control over when
// you want to add views to a particular region, but at the expense of more complexity.
//************************************************************************************************
}
public virtual void OnEmployeeSelected(BusinessEntities.Employee employee)
{
IRegion detailsRegion = regionManager.Regions[RegionNames.DetailsRegion];
object existingView = detailsRegion.GetView(employee.EmployeeId.ToString(CultureInfo.InvariantCulture));
if (existingView == null)
{
IProjectsListPresenter projectsListPresenter = this.container.Resolve <IProjectsListPresenter>();
projectsListPresenter.SetProjects(employee.EmployeeId);
IEmployeesDetailsPresenter detailsPresenter = this.container.Resolve <IEmployeesDetailsPresenter>();
detailsPresenter.SetSelectedEmployee(employee);
IRegionManager detailsRegionManager = detailsRegion.Add(detailsPresenter.View, employee.EmployeeId.ToString(CultureInfo.InvariantCulture), true);
IRegion region = detailsRegionManager.Regions[RegionNames.TabRegion];
region.Add(projectsListPresenter.View, "CurrentProjectsView");
detailsRegion.Activate(detailsPresenter.View);
}
else
{
detailsRegion.Activate(existingView);
}
}