Blog: Posts from November, 2012

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Archive
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Posts from November, 2012
Thursday, November 29, 2012PrintSubscribe
Logging Data Access

Requirements for high-security web applications may require the logging of user credentials when data is accessed. Let’s create two fields, AccessedBy and AccessedOn, and use SQL Business Rules to automatically update these fields.

Adding AccessedBy and AccessedOn Columns

Start SQL Server Management Studio. Connect to your database. In the Object Explorer, right-click on Databases / Northwind / Tables / dbo.Customers node, and press Design.

Design context menu option for Customers table in Northwind database in SQL Server Management Studio.

Add two columns to the table:

Column Name Data Type Allow Nulls
AccessedOn datetime true
AccessedBy nvarchar(50) true

Save the table.

Switch back to Code On Time web application generator. Refresh the project.

Refresh the Code On Time web application project to bring in the new columns into the web app.

Configuring the Fields

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

AccessedOn field under the Customers controller in the Project Explorer.

Change the following properties:

Property Value
Values of this field cannot be edited true
Data Format String g

Press OK to save the field. Double-click on Customers / Fields / AccessedBy node.

AccessedBy field under the Customers controller in the Project Explorer.

Mark the field as read-only:

Property Value
Values of this field cannot be edited true

Press OK to save the field. Right-click on Customers / Business Rules node, and press New Business Rule.

New Business Rule context menu option for Customers controller.

Give this rule the following properties:

Property Value
Type SQL
Command Name Select
View editForm1
Phase Execute
Script
set @AccessedOn = getdate()
set @AccessedBy = @BusinessRules_UserName

Seeing the Results

On the toolbar, press Browse. Navigate to the Customers page, and select a customer. The Accessed On and Accessed By fields will be appear on the form with updated values.

AccessedOn and AccessedBy fields are populated in the user interface.

However, if you check the records in the database, the columns will not be updated.

AccessedOn and AccessedBy fields are not populated in the database.

This is due to the way that the client library works – when data is selected from the database, the business rule adds the values to AccessedOn and AccessedBy before they are displayed in the user interface. If the user tries to save the values, the client library will compare the data requested from the server (with appended values) and any new values. Because the user has not changed these fields, the client library assumes that the values are unchanged and does not update the record.

There are two methods of updating the field value:

  1. Update the field value when the user selects the record.
  2. Update the field value after the user updates the record.

Method 1: Update When User Selects

Switch back to the Project Designer. The business rule will still be open in the Browser window. Change the Script property as follows:

Property New Value
Script
set @AccessedOn = getdate()
set @AccessedBy = @BusinessRules_UserName

update Customers
set AccessedOn=@AccessedOn, AccessedBy=@AccessedBy
where CustomerID=@CustomerID

Press OK to save the business rule. On the toolbar, press Browse.

Navigate to the Customers page, and select a record. The Accessed On and Accessed By fields will be populated in the user interface.

AccessedOn and AccessedBy fields are populated in the web application.

The database record will be updated as well.

AccessedOn and AccessedBy fields are also populated in the database.

Method 2: Update When User Updates

Make sure you are not using the business rule from Method 1. Switch back to the Project Designer. Right-click on Customers / Business Rules and press New Business Rule.

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

Give this business rule the following properties:

Property Value
Type SQL
Command Name Update
Phase Execute
Script
update Customers
set AccessedOn=@AccessedOn, AccessedBy=@AccessedBy
where CustomerID=@CustomerID

Press OK to save. On the toolbar, press Browse.

Navigate to the Customers page. Select a customer, and the fields will be populated in the user interface.

AccessedOn and AccessedBy fields populated in the user interface.

However, the database will not be updated.

AccessedOn and AccessedBy fields not populated in the database.

Press Edit, change a field value, and press OK to save.

Edit, change, and save the customers record in the web application.

The column values will be updated only when the record is updated.

AccessedOn and AccessedBy fields have been populated in the database.

Thursday, November 29, 2012PrintSubscribe
Working with Field Outputs in Designer

A field output specifies a link between data controller commands configured to execute after Insert and the identity-based primary key field of the table.

Field outputs can be found on the Field Outputs tab on a command properties page.

Field Outputs tab on the Command page in the Project Browser.

They can also be found on the Field Outputs tab on a field properties page.

Field Outputs tab on the Field page in the Project Browser.

Option New | New Field Output on the action bar will create a new field output.

New Field Output action bar action in the Project Browser.

The details of a field output can be seen by clicking on the field name or using the context menu option Open.

Open context menu action in the Field Outputs tab in the Project Browser.

Field outputs can be deleted using the context menu option Delete.

Delete context menu option for a field output in the Project Browser.

Field outputs do not have a node in the Project Explorer.

Tuesday, November 27, 2012PrintSubscribe
Advanced User Manager for Custom Membership and Role Provider: Implementing the Business Rules

Instead of allowing the application framework to handle the CRUD operations, let’s prevent the default behavior and implement several business rules. These business rules with use the ASP.NET Membership API to insert, update, and delete users.

Insert

In the Project Explorer, right-click on Users / Business Rules node, and press New Business Rule.

Creating a new business rule for Users data controller.

Assign the following properties:

Property Value
Type C# / Visual Basic
Command Name Insert
Phase Before

Press OK to save the business rule. On the toolbar, press Browse to regenerate the web app and create the business rule file. When finished, right-click on Users / Business Rules / Insert (Code / Before) – r101 node and press Edit Rule in Visual Studio.

'Edit Rule in Visual Studio' context menu option for a code business rule.

Replace the content of the file with the following:

C#:

using System;
using System.Web;
using System.Web.Security;
using MyCompany.Data;
using MyCompany.Security;

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

        /// <summary>
        /// This method will execute in any view before an action
        /// with a command name that matches "Insert".
        /// </summary>
        [Rule("r101")]
        public void r101Implementation(
                    FieldValue userID,
                    string userName,
                    string password,
                    string email,
                    string comment,
                    string passwordQuestion,
                    string passwordAnswer,
                    bool isApproved,
                    DateTime? lastActivityDate,
                    DateTime? lastLoginDate,
                    DateTime? lastPasswordChangedDate,
                    DateTime? creationDate,
                    bool? isLockedOut,
                    DateTime? lastLockedOutDate,
                    int? failedPasswordAttemptCount,
                    DateTime? failedPasswordAttemptWindowStart,
                    int? failedPasswordAnswerAttemptCount,
                    DateTime? failedPasswordAnswerAttemptWindowStart,
                    string roles,
                    string confirmPassword,
                    int? roleID)
        {
            // prevent execution of CRUD operations by the application framework
            PreventDefault();
            // ensure that "Password" and "ConfirmPassword" match
            if (password != confirmPassword)
                throw new Exception(Localize("PasswordAndConfirmationDoNotMatch",
                    "Password and confirmation do not match"));
            // create a user with the Membership API
            MembershipCreateStatus status;
            MembershipUser newUser = Membership.CreateUser(userName, password, email, 
                passwordQuestion, passwordAnswer, isApproved, out status);
            // analyze and report any errors
            if (status != MembershipCreateStatus.Success)
            {
                string error = null;
                switch (status)
                {
                    case MembershipCreateStatus.DuplicateEmail:
                        error = "Duplicate email address.";
                        break;
                    case MembershipCreateStatus.DuplicateProviderUserKey:
                        error = "Duplicate provider key";
                        break;
                    case MembershipCreateStatus.DuplicateUserName:
                        error = "Duplicate user name.";
                        break;
                    case MembershipCreateStatus.InvalidAnswer:
                        error = "Invalid password recovery answer.";
                        break;
                    case MembershipCreateStatus.InvalidEmail:
                        error = "Invalid email address.";
                        break;
                    case MembershipCreateStatus.InvalidPassword:
                        error = string.Format("Invalid password. Requires at least {0} " +
                            "characters and {1} non-alphanumeric characters.",
                            Membership.Provider.MinRequiredPasswordLength,
                            Membership.Provider.MinRequiredNonAlphanumericCharacters);
                        break;
                    case MembershipCreateStatus.InvalidProviderUserKey:
                        error = "Invalid provider user key.";
                        break;
                    case MembershipCreateStatus.InvalidQuestion:
                        error = "Invalid password recovery question.";
                        break;
                    case MembershipCreateStatus.InvalidUserName:
                        error = "Invalid user name.";
                        break;
                    case MembershipCreateStatus.ProviderError:
                        error = "Provider error.";
                        break;
                    case MembershipCreateStatus.UserRejected:
                        error = "User has been rejected.";
                        break;
                }
                throw new Exception(error);
            }
            // assign "Comment" to the new user
            if (!(String.IsNullOrEmpty(comment)))
            {
                newUser.Comment = comment;
                Membership.UpdateUser(newUser);
            }
            // assign "Roles" to the new user
            if (!(String.IsNullOrEmpty(roles)))
            {
                string[] newRoles = Convert.ToString(roles).Split(',');
                foreach (string role in newRoles)
                    if (!(String.IsNullOrEmpty(role)))
                        System.Web.Security.Roles.AddUserToRole(
                            userName, role);
            }
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Linq
Imports System.Text.RegularExpressions
Imports System.Web
Imports System.Web.Security

Namespace MyCompany.Rules

    Partial Public Class UsersBusinessRules
        Inherits MyCompany.Data.BusinessRules

        ''' <summary>
        ''' This method will execute in any view before an action
        ''' with a command name that matches "Insert".
        ''' </summary>
        <Rule("r101")> _
        Public Sub r101Implementation( _
                    ByVal userID As FieldValue, _
                    ByVal userName As String, _
                    ByVal password As String, _
                    ByVal email As String, _
                    ByVal comment As String, _
                    ByVal passwordQuestion As String, _
                    ByVal passwordAnswer As String, _
                    ByVal isApproved As Nullable(Of Boolean),
                    ByVal isLockedOut As Nullable(Of Boolean), _
                    ByVal roles As String, _
                    ByVal confirmPassword As String)
            ' prevent execution of CRUD operations by the application framework
            PreventDefault()
            ' ensure that "Password" and "ConfirmPassword" match
            If (password <> confirmPassword) Then
                Throw New Exception(Localize("PasswordAndConfirmationDoNotMatch",
                                             "Password and confirmation do not match"))
            End If
            Dim status As MembershipCreateStatus
            ' create a user with the Membership API
            Dim newUser As MembershipUser = Membership.CreateUser(userName,
                                  password,
                                  email,
                                  passwordQuestion,
                                  passwordAnswer,
                                  isApproved,
                                  status)
            ' analyze and report any errors
            If (status <> MembershipCreateStatus.Success) Then
                Dim [error] As String = ""
                Select Case status
                    Case MembershipCreateStatus.DuplicateEmail
                        [error] = "Duplicate email address."
                    Case MembershipCreateStatus.DuplicateProviderUserKey
                        [error] = "Duplicate provider key"
                    Case MembershipCreateStatus.DuplicateUserName
                        [error] = "Duplicate user name."
                    Case MembershipCreateStatus.InvalidAnswer
                        [error] = "Invalid password recovery answer."
                    Case MembershipCreateStatus.InvalidEmail
                        [error] = "Invalid email address."
                    Case MembershipCreateStatus.InvalidPassword
                        [error] = String.Format("Invalid password. Requires at least {0} " +
                            "characters and {1} non-alphanumeric characters.",
                            Membership.Provider.MinRequiredPasswordLength,
                            Membership.Provider.MinRequiredNonAlphanumericCharacters)
                    Case MembershipCreateStatus.InvalidProviderUserKey
                        [error] = "Invalid provider user key."
                    Case MembershipCreateStatus.InvalidQuestion
                        [error] = "Invalid password recovery question."
                    Case MembershipCreateStatus.InvalidUserName
                        [error] = "Invalid user name."
                    Case MembershipCreateStatus.ProviderError
                        [error] = "Provider error."
                    Case MembershipCreateStatus.UserRejected
                        [error] = "User has been rejected."
                End Select
                Throw New Exception([error])
            End If
            ' assign "Comment" to the new user
            If (Not (String.IsNullOrEmpty(comment))) Then
                newUser.Comment = comment
                Membership.UpdateUser(newUser)
            End If
            ' assign "Roles" to the new user
            If (Not String.IsNullOrEmpty(roles)) Then
                Dim newRoles() As String = Convert.ToString(roles).Split(",")
                For Each role As String In newRoles
                    If (Not String.IsNullOrEmpty(role)) Then
                        System.Web.Security.Roles.AddUserToRole(userName, role)
                    End If
                Next

            End If
        End Sub
    End Class
End Namespace

Save the file.

Update

Create another business rule with the following properties:

Property Value
Type C# / Visual Basic
Command Name Update
Phase Before

Save the business rule, and generate the web app. Edit the rule in Visual Studio. You may need to press Refresh in the Solution Explorer toolbar of Visual Studio for the rule to appear.

Refresh button on the Solution Explorer may need to be pressed in order for the rule to appear.

Replace the code base with the following.

C#:

using System;
using System.Web.Security;
using MyCompany.Data;
using MyCompany.Security;

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

        /// <summary>
        /// This method will execute in any view before an action
        /// with a command name that matches "Update".
        /// </summary>
        [Rule("r102")]
        public void r102Implementation(
                    FieldValue userID,
                    string userName,
                    FieldValue password,
                    FieldValue email,
                    FieldValue comment,
                    FieldValue passwordQuestion,
                    FieldValue passwordAnswer,
                    FieldValue isApproved,
                    DateTime? lastActivityDate,
                    DateTime? lastLoginDate,
                    DateTime? lastPasswordChangedDate,
                    DateTime? creationDate,
                    FieldValue isLockedOut,
                    DateTime? lastLockedOutDate,
                    int? failedPasswordAttemptCount,
                    DateTime? failedPasswordAttemptWindowStart,
                    int? failedPasswordAnswerAttemptCount,
                    DateTime? failedPasswordAnswerAttemptWindowStart,
                    FieldValue roles)
        {
            // prevent execution of CRUD operations by the application framework
            PreventDefault();
            // get user object by name
            MembershipUser user = Membership.GetUser(userName);
            if (user != null)
            {
                // update "Email" if changed
                if (email.Modified)
                {
                    user.Email = Convert.ToString(email.Value);
                    Membership.UpdateUser(user);
                }
                // update "Is Approved" if changed
                if (isApproved.Modified)
                {
                    user.IsApproved = Convert.ToBoolean(isApproved.Value);
                    Membership.UpdateUser(user);
                }
                // unlock user account if necessary
                if (isLockedOut.Modified)
                {
                    if (Convert.ToBoolean(isLockedOut.Value))
                    {
                        Result.Focus("IsLockedOut", Localize("UserCannotBeLockedOut",
                            "User cannot be locked out. If you want to prevent this " +
                            "user from being able to login then simply mark user as" +
                            " \'Not Approved\'."));
                        throw new Exception(Localize("ErrorSavingUser",
                            "Error saving user account."));
                    }
                    user.UnlockUser();
                }
                // update "Comment" if changed
                if (comment.Modified)
                {
                    user.Comment = Convert.ToString(comment.Value);
                    Membership.UpdateUser(user);
                }
                // update "Roles" if changed
                if (roles.Modified)
                {
                    string[] newRoles = Convert.ToString(roles.Value).Split(',');
                    string[] oldRoles = System.Web.Security.Roles.GetRolesForUser(
                        user.UserName);
                    foreach (string role in oldRoles)
                        if (!(String.IsNullOrEmpty(role)) && (Array.IndexOf(
                            newRoles, role) == -1))
                            System.Web.Security.Roles.RemoveUserFromRole(
                                user.UserName, role);
                    foreach (string role in newRoles)
                        if (!(String.IsNullOrEmpty(role)) &&
                            (Array.IndexOf(oldRoles, role) == -1))
                            System.Web.Security.Roles.AddUserToRole(
                                user.UserName, role);
                }
            }
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System
Imports System.Web.Security

Namespace MyCompany.Rules

    Partial Public Class UsersBusinessRules
        Inherits MyCompany.Data.BusinessRules

        ''' <summary>
        ''' This method will execute in any view before an action
        ''' with a command name that matches "Update".
        ''' </summary>
        <Rule("r102")> _
        Public Sub r102Implementation( _
                    ByVal userID As FieldValue, _
                    ByVal userName As String, _
                    ByVal password As FieldValue, _
                    ByVal email As FieldValue, _
                    ByVal comment As FieldValue, _
                    ByVal passwordQuestion As FieldValue, _
                    ByVal passwordAnswer As FieldValue, _
                    ByVal isApproved As FieldValue, _
                    ByVal lastActivityDate As Nullable(Of DateTime), _
                    ByVal lastLoginDate As Nullable(Of DateTime), _
                    ByVal lastPasswordChangedDate As Nullable(Of DateTime), _
                    ByVal creationDate As Nullable(Of DateTime), _
                    ByVal isLockedOut As FieldValue, _
                    ByVal lastLockedOutDate As Nullable(Of DateTime), _
                    ByVal failedPasswordAttemptCount As Nullable(Of Integer), _
                    ByVal failedPasswordAttemptWindowStart As Nullable(Of DateTime), _
                    ByVal failedPasswordAnswerAttemptCount As Nullable(Of Integer), _
                    ByVal failedPasswordAnswerAttemptWindowStart As Nullable(Of DateTime), _
                    ByVal roles As FieldValue, _
                    ByVal confirmPassword As String, _
                    ByVal roleID As Nullable(Of Integer))
            ' prevent execution of CRUD operations by the application framework
            PreventDefault()
            ' get user object by name
            Dim user As MembershipUser = Membership.GetUser(userName)
            If Not (user Is Nothing) Then
                ' update "Email" if changed
                If email.Modified Then
                    user.Email = Convert.ToString(email.Value)
                    Membership.UpdateUser(user)
                End If
                ' update "Is Approved" if changed
                If isApproved.Modified Then
                    user.IsApproved = Convert.ToBoolean(isApproved.Value)
                    Membership.UpdateUser(user)
                End If
                ' unlock user account if necessary
                If isLockedOut.Modified Then
                    If (Convert.ToBoolean(isLockedOut.Value)) Then
                        Result.Focus("IsLockedOut", Localize("UserCannotBeLockedOut",
                            "User cannot be locked out. If you want to prevent this " +
                            "user from being able to login then simply mark user as " +
                            "'Not Approved'."))
                        Throw New Exception(Localize("ErrorSavingUser",
                                "Error saving user account."))
                    End If
                    user.UnlockUser()
                End If
                ' update "Comment" if changed
                If comment.Modified Then
                    user.Comment = Convert.ToString(comment.Value)
                    Membership.UpdateUser(user)
                End If
                ' update "Roles" if changed
                If roles.Modified Then
                    Dim newRoles() As String = Convert.ToString(roles.Value).Split(",")
                    Dim oldRoles() As String = System.Web.Security.Roles.GetRolesForUser(
                        user.UserName)
                    For Each role As String In oldRoles
                        If Not (String.IsNullOrEmpty(role) And (Array.IndexOf(
                                                                newRoles, role) = -1)) Then
                            System.Web.Security.Roles.RemoveUserFromRole(user.UserName, role)
                        End If
                    Next
                    For Each role As String In newRoles
                        If Not (String.IsNullOrEmpty(role) And (Array.IndexOf(
                                                                oldRoles, role) = -1)) Then
                            System.Web.Security.Roles.AddUserToRole(user.UserName, role)
                        End If
                    Next
                End If
            End If
        End Sub
    End Class
End Namespace

Save the file.

Delete

Create another business rule:

Property Value
Type C# / Visual Basic
Command Name Delete
Phase Before

Save, regenerate the web app, and open the business rule file in Visual Studio. Replace the code:

C#:

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.Security;
using MyCompany.Data;
using MyCompany.Security;

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

        /// <summary>
        /// This method will execute in any view before an action
        /// with a command name that matches "Delete".
        /// </summary>
        [Rule("r103")]
        public void r103Implementation(
                    FieldValue userID,
                    string userName,
                    string password,
                    string email,
                    string comment,
                    string passwordQuestion,
                    string passwordAnswer,
                    bool? isApproved,
                    DateTime? lastActivityDate,
                    DateTime? lastLoginDate,
                    DateTime? lastPasswordChangedDate,
                    DateTime? creationDate,
                    bool? isLockedOut,
                    DateTime? lastLockedOutDate,
                    int? failedPasswordAttemptCount,
                    DateTime? failedPasswordAttemptWindowStart,
                    int? failedPasswordAnswerAttemptCount,
                    DateTime? failedPasswordAnswerAttemptWindowStart)
        {
            // prevent execution of CRUD operations by the application framework
            PreventDefault();
            // delete the user account
            MembershipUser user = Membership.GetUser(userName);
            Membership.DeleteUser(user.UserName);
            // instruct the client library to display the previous view
            Result.ShowLastView();
            // instruct the client library to show a confirmation message
            Result.ShowMessage(String.Format(Localize("UserHasBeenDeleted",
                "User \'{0}\' has been deleted."), user.UserName));
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Linq
Imports System.Text.RegularExpressions
Imports System.Web
Imports System.Web.Security

Namespace MyCompany.Rules
    
    Partial Public Class UsersBusinessRules
        Inherits MyCompany.Data.BusinessRules
        
        ''' <summary>
        ''' This method will execute in any view before an action
        ''' with a command name that matches "Delete".
        ''' </summary>
        <Rule("r103")> _
        Public Sub r103Implementation( _
                    ByVal userID As FieldValue, _
                    ByVal userName As String, _
                    ByVal password As String, _
                    ByVal email As String, _
                    ByVal comment As String, _
                    ByVal passwordQuestion As String, _
                    ByVal passwordAnswer As String, _
                    ByVal isApproved As Nullable(Of Boolean), _
                    ByVal lastActivityDate As Nullable(Of DateTime), _
                    ByVal lastLoginDate As Nullable(Of DateTime), _
                    ByVal lastPasswordChangedDate As Nullable(Of DateTime), _
                    ByVal creationDate As Nullable(Of DateTime), _
                    ByVal isLockedOut As Nullable(Of Boolean), _
                    ByVal lastLockedOutDate As Nullable(Of DateTime), _
                    ByVal failedPasswordAttemptCount As Nullable(Of Integer), _
                    ByVal failedPasswordAttemptWindowStart As Nullable(Of DateTime), _
                    ByVal failedPasswordAnswerAttemptCount As Nullable(Of Integer), _
                    ByVal failedPasswordAnswerAttemptWindowStart As Nullable(Of DateTime), _
                    ByVal roles As String, _
                    ByVal confirmPassword As String, _
                    ByVal roleID As Nullable(Of Integer))
            ' prevent execution of CRUD operations by the application framework
            PreventDefault()
            ' delete the user account
            Dim user As MembershipUser = Membership.GetUser(userName)
            Membership.DeleteUser(user.UserName)
            ' instruct the client library to display the previous view
            Result.ShowLastView()
            ' instruct the client library to show a confirmation message
            Result.ShowMessage(String.Format(Localize("UserHasBeenDeleted",
                "User {0} has been deleted."), user.UserName))
        End Sub
    End Class
End Namespace

Save the code.