Thursday, November 29, 2012

Multi-Field Copy with a C# / Visual Basic Business Rule

It may be necessary to copy similar values from a lookup to a record.

For simple copy operations, the Copy property can be used. For more complex operations, a business rule can be implemented. Let’s implement a C# / Visual Basic business rule to copy shipping information from a customer to an order in a sample Northwind web application.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab and double-click on Orders / Fields / ShipName node.

ShipName field in the Orders controller in Code On Time web application designer.

Change the following propeties.

Property Value
The value of the field is calculated by a business rule expression true
Context Fields CustomerID

Press OK to save the field.

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

New Business Rule context menu option for Orders controller in the Project Explorer.

Give this rule the following properties.

Property Value
Type C# / Visual Basic
Command Name New|Calculate
Phase Execute

Press OK to save the business rule. On the toolbar, press Browse to generate the web application and business rule file.

When complete, right-click on Orders / Business Rules / New|Calculate node, and press Edit Rule in Visual Studio.

Edit Rule in Visual Studio context menu option for a business rule will open the file in Visual Studio.

The business rule handler will open in Visual Studio. Replace the default implementation with the following:

C#:

using System;
using MyCompany.Data;

namespace MyCompany.Rules
{
    public partial class OrdersBusinessRules : MyCompany.Data.BusinessRules
    {

        /// <summary>
        /// This method will execute in any view for an action
        /// with a command name that matches "New|Calculate".
        /// </summary>
        [Rule("r100")]
        public void r100Implementation(
                    int? orderID,
                    string customerID,
                    string customerCompanyName,
                    int? employeeID,
                    string employeeLastName,
                    DateTime? orderDate,
                    DateTime? requiredDate,
                    DateTime? shippedDate,
                    int? shipVia,
                    string shipViaCompanyName,
                    decimal? freight,
                    string shipName,
                    string shipAddress,
                    string shipCity,
                    string shipRegion,
                    string shipPostalCode,
                    string shipCountry)
        {
            // This is the placeholder for method implementation.
            if (!String.IsNullOrEmpty(customerID))
                using (SqlText findCustomer = new SqlText(
                    "select " +
                    "    ContactName, " +
                    "    Address, " +
                    "    City, " +
                    "    Region, " +
                    "    PostalCode, " +
                    "    Country " +
                    "from Customers " +
                    "where  " +
                    "    CustomerID = @CustomerID "))
                {
                    findCustomer.AddParameter("@CustomerID", customerID);
                    if (findCustomer.Read())
                    {
                        UpdateFieldValue("ShipName", findCustomer["ContactName"]);
                        UpdateFieldValue("ShipAddress", findCustomer["Address"]);
                        UpdateFieldValue("ShipCity", findCustomer["City"]);
                        UpdateFieldValue("ShipRegion", findCustomer["Region"]);
                        UpdateFieldValue("ShipPostalCode", findCustomer["PostalCode"]);
                        UpdateFieldValue("ShipCountry", findCustomer["Country"]);
                    }
                }
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System

Namespace MyCompany.Rules

    Partial Public Class OrdersBusinessRules
        Inherits MyCompany.Data.BusinessRules

        ''' <summary>
        ''' This method will execute in any view for an action
        ''' with a command name that matches "New|Calculate".
        ''' </summary>
        <Rule("r100")> _
        Public Sub r100Implementation( _
                    ByVal orderID As Nullable(Of Integer), _
                    ByVal customerID As String, _
                    ByVal customerCompanyName As String, _
                    ByVal employeeID As Nullable(Of Integer), _
                    ByVal employeeLastName As String, _
                    ByVal orderDate As Nullable(Of DateTime), _
                    ByVal requiredDate As Nullable(Of DateTime), _
                    ByVal shippedDate As Nullable(Of DateTime), _
                    ByVal shipVia As Nullable(Of Integer), _
                    ByVal shipViaCompanyName As String, _
                    ByVal freight As Nullable(Of Decimal), _
                    ByVal shipName As String, _
                    ByVal shipAddress As String, _
                    ByVal shipCity As String, _
                    ByVal shipRegion As String, _
                    ByVal shipPostalCode As String, _
                    ByVal shipCountry As String)
            'This is the placeholder for method implementation.
            If Not String.IsNullOrEmpty(customerID) Then
                Using findCustomer As SqlText = New SqlText(
                    "select " +
                    "    ContactName, " +
                    "    Address, " +
                    "    City, " +
                    "    Region, " +
                    "    PostalCode, " +
                    "    Country " +
                    "from Customers " +
                    "where  " +
                    "    CustomerID = @CustomerID ")
                    findCustomer.AddParameter("@CustomerID", customerID)
                    If (findCustomer.Read()) Then
                        UpdateFieldValue("ShipName", findCustomer("ContactName"))
                        UpdateFieldValue("ShipAddress", findCustomer("Address"))
                        UpdateFieldValue("ShipCity", findCustomer("City"))
                        UpdateFieldValue("ShipRegion", findCustomer("Region"))
                        UpdateFieldValue("ShipPostalCode", findCustomer("PostalCode"))
                        UpdateFieldValue("ShipCountry", findCustomer("Country"))
                    End If
                End Using
            End If
        End Sub
    End Class
End Namespace

Save the file. Switch back to the Project Designer, and press Browse on the toolbar.

Navigate to Customers page. Select a customer, and a list of orders will appear underneath. On the action bar, press New Orders. The shipping information will be populated using the customer information.

On the New Orders form, the shipping information has been populated using the values from the customer.

Navigate to the Orders page. On the action bar, press New Orders. The shipping fields will be empty.

New Orders form has no customer selected, so no shipping information is populated.

Select a customer using the Customer Company Name lookup. The shipping information will be populated.

Once a customer is selected, the shipping information is copied.

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