Software Development

Using .NET 2.0 Generics for Custom Entity Collection

Mohammad Ashraful Alam — Mon, 18 Feb 2008 11:12:59 GMT

Generics is a new feature in .NET 2.0 which allows us to create a data structure without committing to a specific data type. In the early age of .net 2.0 (i.e. .net 1.x), while using custom entity model in our application data architecture, we had to create a separate class regarding the collection for each of custom entity.

The custom entity

public class SystemUser
{
    public string _Name, _Password;

    public SystemUser(string name, string password)
    {
        _Name = name;
        _Password = password;
    }

    public string Password
    {
        get { return _Password; }
        set { _Password = value; }
    }

    public string Name
    {
        get { return _Name; }
        set { _Name = value; }
    }

The old age custom entity collection class

For a custom entity "SystemUser" we had to create a separate collection class as below:

public class SystemUserCollection: CollectionBase
{
    public SystemUser this[ int index ]
    {
        get{return ( (SystemUser) List[index]);}
        set{List[index]=value;}
    }
    
    public int Add(SystemUser value)
    {
        return (List.Add(value));
    }
    
    public int IndexOf(SystemUser value)
    {
        return (List.IndexOf(value));
    }
    
    public void Insert(int index, SystemUser value)
    {
        List.Insert(index, value);
    }
    
    public void Remove(SystemUser value)
    {
        List.Remove(value);    
    }
    
    public bool Contains(SystemUser value)
    {
        return (List.Contains(value));    
    }
  
}

Custom entity collection using .net 2.0 generics

The generics in .net 2.0 made developers life extremely easy, we can create a common collection class for all custom business entity with respect to common collection based functionality.

/// <summary>
/// This is the helper collection class, that holds

generic type data.
/// This type will be used to manipulate generic class.
/// </summary>
/// <typeparam name="GenericType"></typeparam>
public class CustomCollection<GenericType> : CollectionBase
{
        /// <summary>
        /// Adds an object to the collection.
        /// </summary>
        /// <param name="GenericObject"></param>
        public void Add(GenericType item)
        {
            InnerList.Add(item);
        }

        /// <summary>
        /// Removes an object from the collection.
        /// </summary>
        /// <param name="index"></param>
        public void Remove(int index)
        {
            InnerList.RemoveAt(index);
        }

        /// <summary>
        /// Gets and sets the appropriate object

in the specified index.
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public GenericType this[int index]
        {
            get { return ((GenericType)List[index]); }
            set { List[index] = value; }
        }

}//end of GenericCollection<GenericType>

Using generic collection

Generic collection classes can be used in the following way:

public static CustomCollection<SystemUser>

GetSampleGenericCollection()
{
    SystemUser user1 = new SystemUser("ashraf", "12345");
    SystemUser user2 = new SystemUser("ehsan", "12345");
    SystemUser user3 = new SystemUser("tuhin", "12345");
    SystemUser user4 = new SystemUser("rabbi", "12345");

    CustomCollection<SystemUser> mySystemUserCollection

= new CustomCollection<SystemUser>();

    mySystemUserCollection.Add(user1);
    mySystemUserCollection.Add(user2);
    mySystemUserCollection.Add(user3);
    mySystemUserCollection.Add(user4);

    return mySystemUserCollection;

}

Download code:

Technorati Tags: .net,coding,programming,C#,sample

ASP.NET Role Based Security: The Basics

Mohammad Ashraful Alam — Mon, 18 Feb 2008 10:31:40 GMT

Authentication and authorization is the two basic part of the user-end security in asp.net web applications. After to successful authentication of a user, authorization takes the place according to which the authenticated user are allowed to access to the corresponding resources in the web application.

Role based security is very basic requirements in the current trend of web applications. Mostly there are two roles involved, which are registered user and the admin users. However in a web application a user can have multiple roles which can be authorized on page and page control level. Today we'll check a basic sample which includes page based authorizations for specific roles.

To implement the basic role based security, there are three points to be considered. In this example we are considering two different roles "member" and "admin". There are two separate folders named "member", which can be accessed by any logged in user, including admin users and "admin", where only the user who contains the "admin" role can access the child resources (page, images etc).

1. Defining the authorization regions in web.config

The following xml tags are required to be added under the "configuration" node of the web.config.

Defining security authorization for "member" users

  <location path="member">
    <system.web>
      <authorization>
        <deny users="?"/>
      </authorization>
    </system.web>
  </location>

Defining security authorization for "admin" users

  <location path="admin">
    <system.web>
      <authorization>
        <allow roles="admin"/>
        <deny users="*"/>
      </authorization>
    </system.web>
  </location>

2. Authenticating the user

After the successful authentication, the following codes are required to establish the form based authentication for the corresponding user.

//Authenticating the user Identity.

System.Web.Security.FormsAuthentication.RedirectFromLoginPage

("member1", this.CheckBox1.Checked);

3. Implementing the role based security

The "Application_AuthenticateRequest" event which was defined in the "Global.asax" file, will include the appropriate codes regarding the role info of the logged in user, which will be accesses each time for any web request in this web application. This can be done in either "cache" or "cookie" mechanism.

Cache based mechanism

protected void Application_AuthenticateRequest(Object sender, EventArgs e)

{

if (HttpContext.Current.User != null)

{

if (HttpContext.Current.User.Identity.IsAuthenticated)

{

if (HttpContext.Current.User.Identity.AuthenticationType != "Forms")

throw new Exception("Only forms authentication is supported, not " +

HttpContext.Current.User.Identity.AuthenticationType);

System.Security.Principal.IIdentity userId = HttpContext.Current.User.Identity;

//if role info is already NOT loaded into cache, put the role info in cache

if (System.Web.HttpContext.Current.Cache[userId.Name] == null)

{

string[] roles;

if (userId.Name == "admin1")

roles = new string[1] { "admin" };//this info will be generally collected from database

else if (userId.Name == "member1")

roles = new string[1] { "member" };//this info will be generally collected from database

else

roles = new string[1] { "public" };//this info will be generally collected from database

//1 hour sliding expiring time. Adding the roles in chache. This will be used in Application_AuthenticateRequest event located in Global.ascx.cs file to attach user Principal object.

System.Web.HttpContext.Current.Cache.Add(userId.Name, roles, null, DateTime.MaxValue, TimeSpan.FromHours(1), System.Web.Caching.CacheItemPriority.BelowNormal, null);

}

//now assign the user role in the current security context

HttpContext.Current.User = new System.Security.Principal.GenericPrincipal(userId, (string[])System.Web.HttpContext.Current.Cache[userId.Name]);

}

Cookie based mechanism

protected void Application_AuthenticateRequest(Object sender, EventArgs e)

{

if (HttpContext.Current.User != null)

{

if (Request.IsAuthenticated == true)

{

if (HttpContext.Current.User.Identity.AuthenticationType != "Forms")

throw new Exception("Only forms authentication is supported, not " +

HttpContext.Current.User.Identity.AuthenticationType);

//Create/Retrieve cookie and initizalyze the role info in the current security context

string userInformation = String.Empty;//where the cookie info will be placed

string[] roles;//where the user role will be placed

// Create the roles cookie if it doesn't exist yet for this session.

if ((Request.Cookies["cnstUserRole"] == null) || (Request.Cookies["cnstUserRole"].Value == ""))

{

if (HttpContext.Current.User.Identity.Name == "admin1")

roles = new string[1] { "admin" };//this info will be generally collected from database

else if (HttpContext.Current.User.Identity.Name == "member1")

roles = new string[1] { "member" };//this info will be generally collected from database

else

roles = new string[1] { "public" };//this info will be generally collected from database

// Create a string to persist the role and user id

userInformation = roles[0] + ";" + Context.User.Identity.Name;

// Create a cookie authentication ticket.

FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(

1, // version

User.Identity.Name, // user name

DateTime.Now, // issue time

DateTime.Now.AddHours(1), // expires every hour

false, // don't persist cookie

userInformation

);

// Encrypt the ticket

String cookieStr = FormsAuthentication.Encrypt(ticket);

// Send the cookie to the client

Response.Cookies["cnstUserRole"].Value = cookieStr;

Response.Cookies["cnstUserRole"].Path = "/";

Response.Cookies["cnstUserRole"].Expires = DateTime.Now.AddMinutes(1);

}//if role cookie not found in local pc

else//we are getting the role info from cookie

{

// Get roles from roles cookie

FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(Context.Request.Cookies["cnstUserRole"].Value);

userInformation = ticket.UserData;

//info[0] contains the single role and info[1] contains the user name

string[] cookieInfo = userInformation.Split(new char[] { ';' });

roles = new string[1] { cookieInfo[0] };

}

//now assign the user role in the current security context

Context.User = new System.Security.Principal.GenericPrincipal(Context.User.Identity, roles);

}//if (Request.IsAuthenticated == true)

}

Download source code:

Technorati Tags: asp.net,security,programming,coding,C#,.net

Simple C# Delegate Sample

Mohammad Ashraful Alam — Fri, 15 Feb 2008 08:47:18 GMT

New developers often ask me about C# delegate, as they got a bit confused about the basic concept and specially maximum of the reference contains and discussed from an advanced view. Well I think delegate is really simple, when you grab it's basic idea.

So what is delegate?

Basically it is similar like the old "C" age function pointer, where functions can be assigned like a variable and called in the run time based on dynamic conditions. C# delegate is the smarter version of function pointer which helps software architects a lot, specially while utilizing design patterns.

At first, a delegate is defined with a specific signature (return type, parameter type and order etc). To invoke a delegate object, one or more methods are required with the EXACT same signature. A delegate object is first created similar like a class object created. The delegate object will basically hold a reference of a function. The function will then can be called via the delegate object.

Sounds easy? If not lets have a look in the code snippets below.

1. Defining the delegate

public delegate int Calculate (int value1, int value2);

2. Creating methods which will be assigned to delegate object

//a method, that will be assigned to delegate objects
//having the EXACT signature of the delegate
public int add(int value1, int value2)
{
    return value1 + value2;            
}
//a method, that will be assigned to delegate objects
//having the EXACT signature of the delegate
public int sub( int value1, int value2)
{
    return value1 - value2;            
}

3. Creating the delegate object and assigning methods to those delegate objects

//creating the class which contains the methods 
//that will be assigned to delegate objects
MyClass mc = new MyClass();

//creating delegate objects and assigning appropriate methods
//having the EXACT signature of the delegate
Calculate add = new Calculate(mc.add);
Calculate sub = new Calculate(mc.sub);

4. Calling the methods via delegate objects

//using the delegate objects to call the assigned methods 
Console.WriteLine("Adding two values: " + add(10, 6));
Console.WriteLine("Subtracting two values: " + sub(10,4));

Pretty simple, huh? Happy coding!!

Download source code:

Technorati Tags: C#,programming,sample,snippet,coding

Software Design Tradeoff Factors

Mohammad Ashraful Alam — Wed, 06 Feb 2008 12:01:47 GMT

In perfect world you can get all of the best things in one place. But in real world it’s not. In software development there are some basic trade-offs when you consider a specific design feature. Exploring these considerations will help you to create the architecture that matches best with the given context.

Performance

Security (code level, encryption etc) VS Performance (code level)

Caching: Memory VS Performance

Object Oriented/Layered Code VS Performance

Scalability VS Deployment (n-tier)

User Experience

Usability

Security (user level) VS Usability (user level)

Usability (user level) VS Functionality (user level)

Robustness (user level) VS Usability (user level)

Rich User Experience

AJAX VS Browser Compatibly Issue

Rich Function (FAT Client) VS Poor Function (Thin Client)

Developer Experience

Development Time

Analysis and Design Time VS Development Time

Object Oriented Programming VS Development Time

Quality Assurance and Control VS Time

Well Engineering VS Modification/Change/Reuse (Understandability) Time

System Data Reliability (back up) VS Maintenance Time

Development Structure

Readability (code level) VS Writability (code level)

Reliability (code level) VS Flexibility (code level)

Developer Improvement

Own Study VS External Resources

Latest/New Practices VS Learning Time (PHP VS .NET etc)

Technorati Tags: architecture,design,coding,software development,concepts

Where Do You Place Your Documents?

Mohammad Ashraful Alam — Thu, 10 Jan 2008 07:54:26 GMT

Putting your documents and codes in organized manner is very very primary requirements to manage your tasks properly. As as developer (well although I contain the highest technical position in the current organization I am working on, I believe that still I am developer!), I do feel to take care about it, specially having some standards will help you to find and manage your documents quickly. Here is a basic sample that I maintain for my end (and encourages my team members to keep the same ;) ).

Folder Structure for Software Projects
src

project-name-solution

project-name-web-1

project-name-web-2

project-name-bll

project-name-dal

samples

sample-web-1

diagrams

mdf

script

doc

analysis

credential-documents

version-and-updates

project-name-versioning.xls

update-requirements v.x.x.doc

primary-client-documents

project-management

proposal-documents

prototypes

srs

technical-documents

testing-documents

Technorati Tags: document,management

Developer Grades: Where Do You Fall-in?

Mohammad Ashraful Alam — Thu, 10 Jan 2008 07:03:01 GMT

I am leading a mid size development team of 15 members. Recently I had to put grades on them to facilitate future assignments on projects. Just thought I could share those grade points, so that you have a quick asses!

Grades	Level	Comments
A+	Outstanding	Fully fitted for enterprise level leadership and architecture.
A	Excellent	Can be a core contributor in architecture for enterprise level projects.
B+	Very Good	Excellent implementer of the architectures for enterprise level projects defined by others. Can take leadership (architecture and management) for mid range application.
B	Good	Nice implementer for mid range projects.
C+	Satisfactory	Moderate implementer for mid range projects. Can be assigned small projects fully.
C	Better than poor	Requires a close guidance for coding tasks. Can be a good tester in code level.
D+	Poor	Not reliable for coding. Can be assigned for UI level fine tuning, technical documentation, deployment.
D	Non-satisfactory	Can't be a direct part in the team. Requires continuous training and monitoring.

Technorati Tags: developer,scale,grade,programmer,management

The .NET Framework 3.5 At a Glance

Mohammad Ashraful Alam — Thu, 10 Jan 2008 06:46:54 GMT

All .NETTERS! Download the pdf poster here by which you can see .net 3.5 at a glance!

Check Paul's blog for a quick note!

Creating a Performance Benchmark Framework for Your .NET Codes

Mohammad Ashraful Alam — Thu, 22 Nov 2007 10:32:48 GMT

Performance is a one of the basic requirements in the most of the current trend of web applications. While designing software architecture, there are several technologies kept available for the designers. Among these available options, some of techniques may includes multiple solutions, combining of those can create a case, where the basic performance output can't be determined based on the common sense and/or in depth knowledge on the corresponding topics. In short, based upon different options the software architect needs to determine the appropriate object model which fits best with the current application requirement.

The Object Model

There are three layers of our test framework object model, as follows:

The Program Class: This is the starter class, which creates the requires instances to start the test operation. The corresponding caller method initializes the Runner class along with the number of iterations to be performed for each test case.

The Runner Class: The runner class includes one or multiple methods, which calls a bunch of methods of executor class, each of which contains required functionalities to call the test cases appropriately.

The Runner Base Class: One important issue with respect to the runner class is, we need to have a way to keep track to execution time for each run and finally we need to determine the average execution time. For this purpose, to perform required initialization and support common reporting feature of test cases, we considered a base class, which includes all tracking data to isolate individual test cases and reporting functionalities. We have used C# delegate to have a very structured and reusable object model regarding this common functionalities. The methods of the inherited class uses this features accordingly.

The Executor Class: The executor class contains the very basic codes with respect to a particular test case.

The Sample Codes

The Program Class

class Program
    {
        static void Main(string[] args)
        {
            Output.WriteLine("Test starts: " + DateTime.Now.ToString());
            //----------------------------------------
            SampleRunner s1 = new SampleRunner(10);
            s1.RunBenchmarks();
            //----------------------------------------
            Output.WriteLine("Test ends: " + DateTime.Now.ToString());
            Console.ReadLine();
        }
    }

The Runner Base Class

public class SampleRunnerBase
    {
        protected delegate void DoWork(string text);
 
        long _Start;
        long _Stop;
        double _Total = 0;
        double _TotalSecs;
        double _TotalAvgSecs;
        int _Repeats;
        protected int _RepeatsToDo; 
 
        public SampleRunnerBase(int repeats)
        {
            _RepeatsToDo = repeats;
        }
 
        private void Init()
        {
            _Total = 0;
            _TotalSecs = 0;
            _TotalAvgSecs = 0;
            _Repeats = _RepeatsToDo;
        }
 
        private void ReportResults()
        {
            _TotalSecs = _Total / 10000000;
            _TotalAvgSecs = _Total / 10000000 / _RepeatsToDo;
 
            Output.WriteLine("Avg: " + _TotalAvgSecs + " s");
        }
 
        protected void RunBenchmark(DoWork func, string text)
        {
            if (null != func)
            {
                Init();
                while (_Repeats-- > 0)
                {
                    _Start = DateTime.Now.Ticks;
                    func(text);
                    _Stop = DateTime.Now.Ticks;
                    _Total += _Stop - _Start;
                }
                ReportResults();
            }
        }
    }

The Runner Class

public sealed class SampleRunner : SampleRunnerBase
    {
        public SampleRunner(int repeats)
            : base(repeats)
        {
        }
 
        public void RunBenchmarks()
        {
 
            Output.WriteLine("Running Simple Sample Benchmark");
            Output.WriteLine("--------------------------------");
            RunSample1();
            RunSample2();
        }
 
        private void RunSample1()
        {
            Output.WriteLine("Running Sample 1");
            SampleExecutor runner = new SampleExecutor();
            RunBenchmark(new DoWork (runner.DoSample1), "");
        }
 
        private void RunSample2()
        {
            Output.WriteLine("Running Sample 2");
            SampleExecutor runner = new SampleExecutor();
            RunBenchmark(new DoWork(runner.DoSample2), "");
        }
 
    }

The Executor Class

public class SampleExecutor
    {
        public void DoSample1(string text)
        {
            //do something
        }
 
        public void DoSample2(string text)
        {
            //do something
        }
    }

Download source code:

Technorati Tags: Performance,.net,C#,Testing,Framework,Benchmark

Software Development

Using .NET 2.0 Generics for Custom Entity Collection

ASP.NET Role Based Security: The Basics

Simple C# Delegate Sample

3. Creating the delegate object and assigning methods to those delegate objects

Software Design Tradeoff Factors

Performance

User Experience

Developer Experience

Developer Improvement

Where Do You Place Your Documents?

Folder Structure for Software Projects src

Developer Grades: Where Do You Fall-in?

The .NET Framework 3.5 At a Glance

Creating a Performance Benchmark Framework for Your .NET Codes

Folder Structure for Software Projects
src