Blog: Posts from May, 2012

Code On Time web applications designed for Internet access have an option to include a built-in Membership Manager. This tool works on top of Microsoft ASP.NET Membership to simplify user and role management in generated apps. It uses exactly the same data controller architecture as the rest of data controllers in a project.

Data controllers aspnet_Membership and aspnet_Roles are automatically created in a web application if the membership feature is enabled.

This is a typical view of Membership Manager presented if you sign in as admin and navigate to Membership page.

The data controller files can be changed in Visual Studio but the changes will be overwritten by the application generator.

Instead, consider the data controller virtualization when you need to modify the membership manager.

Select the project name on the start page of the generator and choose Develop option. Visual Studio will load the project for editing. Create a new code file Class1.cs(vb) under ~/App_Code/Security folder of your project.

Enter the following definition of the partial class MembershipBusinessRules to virtualize the data controller definition at runtime.

C#:

using System;
using MyCompany.Data;

namespace MyCompany.Security
{
    public partial class MembershipBusinessRules
    {
        public override bool SupportsVirtualization(string controllerName)
        {
            return true;
        }

        protected override void VirtualizeController(string controllerName)
        {
            // remove lookup capability from the field "UserId"
            NodeSet().SelectField("UserId")
                    .SetItemsStyle(null)
                    .SetItemsController(null)
                    .SetItemsNewView(null);
            // select "grid1" view 
            NodeSet().SelectView("grid1")
                // add data field "UserId"
                .CreateDataField("UserId")
                    .SetReadOnly(true)
                // delete data field "Comment"
                .SelectDataField("Comment")
                    .Delete();
            // select "grid1" view
            NodeSet().SelectView("grid1")
                // re-arrange the data fields
                .ArrangeDataFields("UserUserName", "Email", "UserId");
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System

Namespace MyCompany.Security

    Partial Public Class MembershipBusinessRules
        Public Overrides Function SupportsVirtualization(controllerName As String) As Boolean
            Return True
        End Function

        Protected Overrides Sub VirtualizeController(controllerName As String)
            ' remove lookup capability from the field "UserId"
            NodeSet().SelectField("UserId") _
                .SetItemsStyle(Nothing) _
                .SetItemsController(Nothing) _
                .SetItemsNewView(Nothing)

            ' select "grid1" view, add data field "UserId", and delete data field "Comment"
            NodeSet().SelectView("grid1") _
                .CreateDataField("UserId") _
                    .SetReadOnly(True) _
                .SelectDataField("Comment") _
                    .Delete()
            ' select "grid1" view and re-arrange the data fields
            NodeSet().SelectView("grid1") _
                .ArrangeDataFields("UserUserName", "Email", "UserId")
        End Sub
    End Class

End Namespace

The new partial class complements the standard class MembershipBusinessRulesBase included in the application framework. It is possible to override any standard methods such as SignUpUser or UpdateUser. The implementation above overrides the data controller virtualization methods only.

Save the code file and navigate to Membership Manager.

You will see the global unique ID of each user. The data field Comment is not visible anymore. The remaining data fields are re-arranged.

End users of Code On Time web applications have some impressible data filtering capabilities available to them. User-defined filters are also called “soft” filters. They can be canceled or activated at will.

Application developers can activate “soft” filters programmatically. For example, it may be appropriate to limit the amount of data in some data views based on a user identity or value of a session variable. Users can alter such “soft” filters on their own if a larger dataset is required.

Consider the Orders screen in the Northwind sample application.

An SQL Business Rule can be created to limit the list orders to those that meet a specific criteria without user intervention.

Select Orders data controller in Project Designer and enter a new business rule with the following properties.

-- assign a filter if the client-side data view is not tagged
if @BusinessRules_Tags is null
begin
    -- tag the data view
    set @BusinessRules_Tags = 'Filtered'
    -- filter by Employee Name
    set @EmployeeLastName_Filter_Equals = 'Callahan'
    -- filter Ship Via Company Name by two values
    set @ShipViaCompanyName_Filter_Includes1 = 'Speedy Express'
    set @ShipViaCompanyName_Filter_Includes2 = 'United Package'
    -- assign a filter range to Freight
    set @Freight_Filter_Between1 = 10
    set @Freight_Filter_Between2 = 30
    -- assign a filter range to Order Date
    set @OrderDate_Filter_Between1 = '1/1/1998'
    set @OrderDate_Filter_Between2 = '6/1/1998'
    -- let the user know that the "soft" filter has been applied
    set @Result_ShowViewMessage = 'A "soft" filter has been applied.'
end

This is the data controller hierarchy after the rule has been saved.

Generate the app and navigate to Orders page once more. A significantly shorter list of orders is rendered.

A user can cancel some elements of the filter or apply a filter of their own. The script of the business rule assigns “Filtered” tag to the client-side data view to prevent interference with user actions.

You can also assign a “soft” filter with business rules written in C# or Visual Basic .