Tuesday, December 8, 2009

Coffee Talk


is a relaxed time

where people

can share, dessert, coffee and fellowship

with the IT freaks

We Cordially invite you to join with us

When:Thursday,10 Dec09

Where: ISS,NUS

Time: 5PM to 6PM

Directions: Classroom 4-6(Level 4)

Mediator: Mr. Leonard Nee (Senior Programme Director, ISS)

Topic for discussion : IT Trends 2009/10

--------ISS-SCS Student Chapter----------

Thursday, November 26, 2009

ASP.Net Application state, difference between application, viewstate & session state

What is ASP.NET Application State?
Application state is a data repository available to all classes in an ASP.NET application. Application state is stored in memory on the server and is faster than storing and retrieving information in a database. Unlike session state, which is specific to a single user session, application state applies to all users and all sessions. Therefore, application state is a useful place to store small amounts of often-used data that does not change from one user to another.
What is Postback?
When an action occurs (like button click), the page containing all the controls within the tag performs an HTTP POST, while having itself as the target URL. This is called Postback.
ASP.NET View State
ASP.NET Web pages provide view state, which is a way for you to store information directly in the page that you want to persist between postbacks.
ASP.NET Cookies
A cookie is a small bit of text that accompanies requests and pages as they go between the Web server and browser. The cookie contains information the Web application can read whenever the user visits the site. Creating CookiesResponse.Cookies["userName"].Value = "patrick";Response.Cookies["userName"].Expires = DateTime.Now.AddDays(1); HttpCookie aCookie = new HttpCookie("lastVisit");aCookie.Value = DateTime.Now.ToString();aCookie.Expires = DateTime.Now.AddDays(1);Response.Cookies.Add(aCookie);
Getting Cookiesif(Request.Cookies["userInfo"] != null){ System.Collections.Specialized.NameValueCollection UserInfoCookieCollection; UserInfoCookieCollection = Request.Cookies["userInfo"].Values; Label1.Text = Server.HtmlEncode(UserInfoCookieCollection["userName"]); Label2.Text = Server.HtmlEncode(UserInfoCookieCollection["lastVisit"]);}

Differences between Session and ViewStates
"Session" is data stored per user session. "Viewstate" is an ASP.NET thing. It's a way for the application to maintain state about a particular form and its child controls. Your ASP.NET application might consist of several pages/forms. There might be a piece of data that you want to access across all pages. You could place that in a Session variable. However, you rarely need to worry about ViewState, ASP.NET manages that itself.

Viewstate variables are stored in the HTML of your page. They are encoded so they are not easily readable, but they are not encrypted. This is generally the best scope to use when you have a variable that is valid for a particular page and you want to store the value between postbacks. Once theuser navigates to another page the value is lost.Session variables are stored on the server (in RAM by default) and are persisted between all pages.

Different between application and session state
The difference is in the length of their existance.An application variable exists from when the application is first 'run' (The first time a page in the app is used) and exists until the application is stopped on the server, either through IIS or the actual machine being turned off or rebooted.A session variable is created for the instance of the browser accessing the site and will only be available until that browser is closed or the session times out.

ASP.NET Session State

ASP.NET session state enables you to store and retrieve values for a user as the user navigates to different ASP.NET pages that make up a Web application. HTTP is a stateless protocol, meaning that your Web server treats each HTTP request for a page as an independent request; by default, the server retains no knowledge of variable values used during previous requests. As a result, building Web applications that need to maintain some cross-request state information (applications that implement shopping carts, data scrolling, and so on) can be a challenge. ASP.NET session state identifies requests received from the same browser during a limited period of time as a session, and provides the ability to persist variable values for the duration of that session.
ASP.NET session state is enabled by default for all ASP.NET applications. ASP.NET session-state variables are easily set and retrieved using the Session property, which stores session variable values as a collection indexed by name. For example, you can create create the session variables FirstName and LastName to represent the first name and last name of a user, and sets them to values retrieved from TextBox controls.
Basic use of Session in ASP.NET (C#):
STORE: Session["mydataset")=ds;
RETRIEVE: DataSet ds = (DataSet)Session["mydataset"];
Storage location
InProc - session kept as live objects in web server (aspnet_wp.exe).
StateServer - session serialized and stored in memory in a separate process (aspnet_state.exe). State Server can run on another machine
SQLServer - session serialized and stored in SQL server
- Fastest, but the more session data, the more memory is consumed on the web server, and that can affect performance.
StateServer - When storing data of basic types (e.g. string, integer, etc), in one test environment it's 15% slower than InProc. However, the cost of serialization/deserialization can affect performance if you're storing lots of objects. You have to do performance testing for your own scenario.
SQLServer - When storing data of basic types (e.g. string, integer, etc), in one test environment it's 25% slower than InProc. Same warning about serialization as in StateServer.

ASP.Net Web Services

  • A programming model that provides the ability to exchange messages in a scalable, loosely coupled and platform neutral environment using standard protocols such as HTTP,XML,XSD,SOAP and WSDL.

  • The SOAP based XML messages exchanged between a XML web service and its clients can be structured and typed or loosely defined.

  • The flexibility of using a text format such as XML enables the message exchange to evolve over time in a loosely coupled way.

Web Services - are a group of closely related, emerging technologies that describe a service oriented, component based application architecture that is based on an open, internet centric infrastructure.

XML,SOAP - a simple XML based protocol for exchanging structured and typed information as the web. The protocol contains no application or transport semantics which makes it highly modular and extensible.

WSDL - Web services Definition Language (similar to method signature). It is an XML based language used to define web services and describe how to access them. It is SOAP's interface definition language.

DISCO - (Discovery file) Holds reference to all the web services hosted on a server.

UDDI (Universal Description, Discovery and Integration)

Client Machine ---- URI of web service ----> IIS (port 80) ------> ASP.Net run time-----

----> Web services Handler ------> creates an instance of MyWebService and invokes the called method.Any parameters required by method are deserialized from SOAP packet and passed to method as .Net objects.

MyWebService ---------returns---> Computed value -----serializes---> data to XML document wrapped in SOAP packet ------>ASP.Net runtime ----response---->IIS----respond --->Client

I will update this article with an example later .....

ASP.Net Web.Config File

What is Web.Config File?
Web.config file, as it sounds like is a configuration file for the Asp .net web application. An Asp .net application has one web.config file which keeps the configurations required for the corresponding application. Web.config file is written in XML with specific tags having specific meanings.
What is Machine.config File?
As web.config file is used to configure one asp .net web application, same way Machine.config file is used to configure the application according to a particular machine. That is, configuration done in machine.config file is affected on any application that runs on a particular machine. Usually, this file is not altered and only web.config is used which configuring applications.
What can be stored in Web.config file?
There are number of important settings that can be stored in the configuration file. Here are some of the most frequently used configurations, stored conveniently inside Web.config file.
  • Database connections

  • Session States

  • Error Handling

  • Security
Database Connections:
The most important configuration data that can be stored inside the web.config file is the database connection string. Storing the connection string in the web.config file makes sense, since any modifications to the database configurations can be maintained at a single location. As otherwise we'll have to keep it either as a class level variable in all the associated source files or probably keep it in another class as a public static variable.
But if this is stored in the Web.config file, it can be read and used anywhere in the program. This will certainly save us a lot of alteration in different files where we used the old connection.
Lets see a small example of the connection string which is stored in the web.config file.

As you can see it is really simple to store the connection string in the web.config file. The connection string is referenced by a key which in this case is "ConnectionString". The value attribute of the configuration file denotes the information about the database. Here we can see that if has database name, userid and password. You can define more options if you want.
There is a very good website that deals with all sorts of connection strings. Its called http://www.connectionstrings.com/ , in the website you will find the connection strings for most of the databases.

Lets see how we access the connection string from our Asp .net web application.
using System.Configuration;
string connectionString = (string )ConfigurationSettings.AppSettings["ConnectionString"];

The small code snippet above is all that is needed to access the value stored inside the Web.config file.

Thursday, November 19, 2009

Microsoft 2010 Beta products downloads

Microsoft 2010 Beta products downloads

Dear all,

Link for details & downloading the Microsoft 2010 Beta products - Office 2010, SharePoint Server 2010, Visio 2010, Project 2010 and Office Web Apps


Enjoy :-)

J.Chandra Singh

Monday, September 14, 2009

Invitation for ISS-SCS Launch

Dear friends,
I am happy to send you the Invitation and Programme Agenda of our institute's most auspicious event in its history.The launch of ISS-SCS Student Chapter on 25th September, 2009 on 5pm at ISS.
Your cheerful presence will make it a grand success. Inorder to acknowledge your kind presence you will be presented a memorable gift (a USB hub for everyone).

Come, lets record our foot in this Golden Event of our Institute.

Note: I have sent email request to Megan seeking permission. Let you know once approved.

Thanks & Regards,
Chandra Singh Jeyaraj
Class representative

Wednesday, August 12, 2009

Nominations Invited for ISS-SCS

Dear Friends,
I hope you all know about the ISS-SCS Student chapter.
(If you dont know please view that at our official website:
http://sa30-iss-nus.blogspot.com/2009/08/iss-scs-student-chapter.html )

Nominations are now open for the following position in ISS-SCS Student Chapter
a. President
b. Three vice-presidents
c. Honorary Secretary
d. Honorary Treasurer
e. Four council members (portfolios - orientation, student welfare and services, industry liaison, publicity and publications etc).

If you are interested in any of these position please send in your nominations to sunyifan1984@gmail.com.

Please send your nominations before 16-08-09, Sunday Midnight.
J.Chandra Singh

Saturday, August 8, 2009

ISS-SCS Student Chapter

Dear Friends,
Please go through the forwarded message sent by the M.Tech students regarding ISS-SCS (Singapore Computer Society) Students Chapter.

Chandra Singh

---------- Forwarded message ----------

Hi Chandra,

Being the class the representative of DipSA 30 I would like you to forward this mail to all your fellow-mates who seek clarifications on ISS-SCS student chapter.

As there are lot of Hue and cry about the student chapter and since many of them didn’t understand what we are trying to communicate. I take this chance to address all the queries regarding the ISS-SCS student chapter.


What is ISS-SCS student chapter?
Ans: An official acceptance from ISS to become the member of SCS community.

When is the ISS-SCS student chapter going to launch?
Ans: On September 25th 2009.

Do I need to fill in any form or any other formalities to become the SCS member?
Ans: No. By default after the launch of ISS-SCS student chapter all the full-time students of DipSA, MTech KE and SE become the SCS members.

Do I need to pay to become the member of SCS?
Ans: You don’t have to pay any money, as a full-time student you can enjoy all the privileges of SCS member.

What is going to happen on the day of ISS-SCS launch?
Ans: The president and other senior members of SCS will be present and mutual acceptance and sign-off between ISS-SCS will take place.

Do we have any student activities planned on the same day?
Ans: Yes. We are asked to conduct minimum of two-events on the day of launch. This is to expose our student talents in front of SCS senior members.

I have some ideas for the student activities, which is the best place to post my ideas?
Ans: Please login to IVLE, you can find SCS Chapter, under the forum please share us your valuable ideas.

What does SCS expect out of ISS students?
Ans: The SCS defines nearly 10 roles starting from president, secretary, treasury etc and each role has its responsibilities to full fill. We are also expected to conduct elections to fill in these roles.

I want to clearly know about the roles and responsibilities?
Ans: We are still in talks with SCS about the roles and responsibilities. Once we get the detailed information, we will be posting it in the IVLE and will send a separate mail to everyone.

Is there any restrictions or qualification for the nominations?
Ans: There is no restriction or qualifications any full-time students can nominate for the above positions.

11. I need further more information, whom should I contact?
Ans: gvdinesh4u@gmail.com , hninlekyaw@gmail.com , gpraveenkumar17@gmail.com , sunyifan1984@gmail.com , divvs18@gmail.com

Thanks & Regards,

Friday, July 17, 2009

Congrats Thandar & Lwin Htoo Ko

Congrats Thandar & Lwin Hto Ko! for your best performance in First & Second Semester respectively on behalf of SA-30.

Wednesday, July 8, 2009

AD Project walk through

Dear friends,
The following message I got from Lecturer Venkat.

Pls announce to the class that I would have a brief walkthrough/demo on some aspects of coding on Thursday 9-July-2009 3.30pm to 4.30pm at CR 3-5. Attendence NOT compulsory. Team representatives may send in their questions by this evening (I will try to address these to the extent possible tomorrow).


AD Project walk through

Dear friends,
The following message I got from Lecturer Venkat.

Pls announce to the class that I would have a brief walkthrough/demo on some aspects of coding on Thursday 9-July-2009 3.30pm to 4.30pm at CR 3-5.

Attendence NOT compulsory.

Team representatives may send in their questions by this evening (I will try to address these to the extent possible tomorrow).


Thursday, July 2, 2009


Dear friends,
Here is our class trip plan: Saturday, 04/07/09 8.00 AM
- Gather at Maina Bay MRT (MA Ei Khine will be there already to guide us to Ferry point)8.10 AM
- Take City Bus to Ferry point (10 min travel)8.30 AM
- Reach ferry point & buy tickets (Joe Joe will be there already to buy ticket for all)9.00 AM
- Ferry starts moving...9.30 AM
- Reach Kusu island Games, Football, food, etc.,....there 5.30 PM

- Take Ferry to return.

To go & return ferry cost: $15.00

IMPORTANT Please tell or sms your coming on Friday evening to me: Cell no. : 8488 2814 or Wan Yu: 98838511 or Win Phyo: 81906851

Saturday, June 27, 2009

New T-Shirt design

Dear friends,
From the suggestions got from our class friends, we placed this new design.
Chandra Singh

Friday, June 26, 2009

Our Class T-Shirt

Hi friends,

The design and model for our class T-Shirt.

I hope everybody will agree with this.

Tuesday, June 23, 2009

Asp.net revision

Dear friend,
Derik agreed to come for revision after the last presentation tomorrow at Room 3-5.
Also, Jessie will distribute the pre-reading materials at 1:30 pm tomorrow .
So please make yourself conventient to attend these events.

Thanks for your co-operation.

Chandra singh,
Class Representative.

Saturday, June 13, 2009

Precaution to H1N1 flu

Dear friends,
Please record your temperature every Monday before 10am, by online or sms.
This is instructed by ISS management on behalf of Government.

Below is the Message I recieved from Ms.Matilda:-

pl inform students re this - pl make an announcement on Monday that it has to be done till 2 august

Temperature-Taking Exercise on Every Monday Starting From 15 June 09

4. The Ministry of Education has asked all Institutes of Higher Learning to conduct institution-wide temperature taking exercise for staff and students on every Monday until the end of the vacation period.

5. As such, all NUS staff, graduate and undergraduate students who are on campus, as well as students staying in NUS Halls and Residences should report their temperatures by 10.00 am on every Monday until 2 August 2009. The next exercise will be conducted on Monday, 15 June 09.

6. Details on the Online Temperature Reporting and Temperature Reporting by SMS are available at www.nus.edu.sg/flupandemic. If you encounter problems with the URL link, please copy and paste the URL into the browser address bar.

Wednesday, April 22, 2009


You can view my presentation about Mash-up & composite application in the follwing address.


It will be much useful to others if you put your topic in this blog.
Don't forget this blog is for our class.
Chandra singh.

Wednesday, April 1, 2009

SA(30) of ISS in National University of Singapore

This is the official blog of the SA(30) members studying in Institute of Systems Science (ISS) of National University of Singapore (NUS). All members are welcome to join.