Business Rules/Logic

A dedicated “Status” field in a database table is a simple and easy to implement method of separating “draft” and “committed” data. For example, orders stored in a database will be explicitly marked with a status of “Committed” if no changes are allowed to them. Orders still being composed will be marked with a status of “Draft”. The application must ignore draft data and have it visible only on the order entry page.

Adding the “Status” Column

Start SQL Server Management Studio. In the Object Explorer, right-click on Databases / Northwind and press New Query.

Paste in the following script to add the table column and mark all existing orders as “Committed”.

alter table Orders
add Status nvarchar(50) default 'Draft'
go

update Orders
set Status = 'Committed'
go

On the toolbar, press Execute to run the query.

Controlling Display of Draft Orders

Start the web application generator. Select the project name and click Settings. Press Business Logic Layer and enable shared business rules. Click Finish and regenerate the project.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Orders controller node, and press Edit Handler in Visual Studio.

The shared business rule file will open in Visual Studio. Replace the file with the following code:

C#:

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using MyCompany.Data;

namespace MyCompany.Rules
{
    public partial class SharedBusinessRules : MyCompany.Data.BusinessRules
    {
        
        public SharedBusinessRules()
        {
        }

        protected override void EnumerateDynamicAccessControlRules(string controllerName)
        {
            if (Context.Request.UrlReferrer != null)
            {
                if (Context.Request.UrlReferrer.ToString().ToLower().Contains("orderform.aspx"))
                    RegisterAccessControlRule("OrderID", 
                        "select OrderID from Orders where Status = 'Draft'", 
                        AccessPermission.Allow);
                else
                    RegisterAccessControlRule("OrderID", 
                        "select OrderID from Orders where Status = 'Committed'", 
                        AccessPermission.Allow);
            }
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Linq

Namespace MyCompany.Rules

    Partial Public Class SharedBusinessRules
        Inherits MyCompany.Data.BusinessRules

        Public Sub New()
            MyBase.New()
        End Sub

        Protected Overrides Sub EnumerateDynamicAccessControlRules(controllerName As String)
            If Context.Request.UrlReferrer <> Nothing Then
                If Context.Request.UrlReferrer.ToString().ToLower().Contains("orderform.aspx") Then
                    RegisterAccessControlRule("OrderID",
                                            "select OrderID from Orders where Status = 'Draft'",
                                            AccessPermission.Allow)
                Else
                    RegisterAccessControlRule("OrderID",
                                            "select OrderID from Orders where Status = 'Committed'",
                                            AccessPermission.Allow)
                End If
            End If
        End Sub
    End Class
End Namespace

The implementation will conditionally register a dynamic access control rule that will apply to a view of any data controller with an OrderID data field. If the user is interacting with an application page ~/Pages/OrderForm.aspx, then only data that matches orders with a status of “Draft” is allowed. Otherwise, only data that matches orders with a status of “Committed” is included in the returned data set.

Adding “Submit Order” Action

In the Project Explorer, right-click on Orders / Actions / ag2 (Form) node, and press New Action.

Assign the following values:

Press OK to save the action. Drop Orders / Actions / ag2 (Form) / a101 – Custom, SubmitOrder | Submit Order node on the left side of a100 – Report | Order Report to place it first.

Adding Business Rule

Right-click on Orders / Business Rules node, and press New Business Rule.

Assign these values:

update Orders
set Status = 'Committed'
where OrderID = @OrderID

set @Result_NavigateUrl = 'OrderForm.aspx'

The business rule will set Status column of the selected order to “Committed” and refresh the page loaded in the web browser. Press OK to save.

Testing the Results

On the toolbar, press Browse. Navigate to the Order Form page. Create a new order and return to the grid. Note that only a single draft order is listed.

Navigate to the Orders page. Note that the all of the orders are displayed except for the draft order.

The draft order will also not be visible in any data controllers based on database views if they relate to orders. For example, page Reports | Order Subtotals will not display the new order. The dynamic access control rule explained above filters the order out.

Go back to the Order Form page, and select the draft order. Click on the “Submit Order” button.

The browser will refresh the page and display an empty list of orders.

The order will now be displayed on Orders page.

It will also be displayed on Order Subtotals page that can be found under the Reports option in the application navigation menu.

Let’s create a calculated field in the Employees controller that will combine First Name and Last Name fields.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Employees / Fields node, and press New Field option.

Assign the following properties:

Press OK to save.

In the Project Explorer, drag Employees / Fields / FullName field node and drop it onto Employees / Views / createForm1 to add a data field.

Right-click on Employees / Fields / FullName node, and press Add Code Converter.

Double-click on Employees / Fields / FullName node, and change the Context Fields property:

On the toolbar, press Browse to generate the web application and code business rule.

Right-click on Employees / Business Rules / FullName_Convertor and press Edit Rule in Visual Studio.

The business rule file will open in Visual Studio. Replace the default code with the following:

C#:

using System;
using MyCompany.Data;

namespace MyCompany.Rules
{
    public partial class EmployeesBusinessRules : MyCompany.Data.BusinessRules
    {
        
        /// <summary>
        /// Rule "FullName_Converter" implementation:
        /// This method will execute in any view before an action
        /// with a command name that matches "Calculate|Insert|Update".
        /// </summary>
        [Rule("r100")]
        public void r100Implementation(
                    int? employeeID, 
                    string lastName, 
                    string firstName, 
                    string title, 
                    string titleOfCourtesy, 
                    DateTime? birthDate, 
                    DateTime? hireDate, 
                    string address, 
                    string city, 
                    string region, 
                    string postalCode, 
                    string country, 
                    string homePhone, 
                    string extension, 
                    string notes, 
                    int? reportsTo, 
                    string reportsToLastName, 
                    string photoPath, 
                    string fullName)
        {
            if (!(String.IsNullOrEmpty(firstName)) && !(String.IsNullOrEmpty(lastName)))
                UpdateFieldValue("FullName", firstName + ' ' + lastName);
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System

Namespace MyCompany.Rules
    
    Partial Public Class EmployeesBusinessRules
        Inherits MyCompany.Data.BusinessRules
        
        ''' <summary>
        ''' Rule "FullName_Converter" implementation:
        ''' This method will execute in any view before an action
        ''' with a command name that matches "Calculate|Insert|Update".
        ''' </summary>
        <Rule("r100")>  _
        Public Sub r100Implementation( _
                    ByVal employeeID As Nullable(Of Integer),  _
                    ByVal lastName As String,  _
                    ByVal firstName As String,  _
                    ByVal title As String,  _
                    ByVal titleOfCourtesy As String,  _
                    ByVal birthDate As Nullable(Of DateTime),  _
                    ByVal hireDate As Nullable(Of DateTime),  _
                    ByVal address As String,  _
                    ByVal city As String,  _
                    ByVal region As String,  _
                    ByVal postalCode As String,  _
                    ByVal country As String,  _
                    ByVal homePhone As String,  _
                    ByVal extension As String,  _
                    ByVal notes As String,  _
                    ByVal reportsTo As Nullable(Of Integer),  _
                    ByVal reportsToLastName As String,  _
                    ByVal photoPath As String,  _
                    ByVal fullName As String)
            If (Not (String.IsNullOrEmpty(firstName)) AndAlso Not (String.IsNullOrEmpty(lastName))) Then
                UpdateFieldValue("FullName", firstName + " " + lastName)
            End If
        End Sub
    End Class
End Namespace

Save the file.

Switch back to the web application generator. On the toolbar, press Browse.

Navigate to the Employees page, and create a new employee. Type a value for Last Name and First Name.

The Full Name field will be updated when the user presses Tab or shifts focus away from the field.