Aleem's Blog

Finally Moved to Wordpress !

2006-10-12T21:47:00.000+05:00

Finally, I have shifted my Blog to Wordpress. My Wordpress Blog is http://aleemkhan.wordpress.com, the feed address is http://aleemkhan.wordpress.com/feed. I will discontinue posting here and will be posting only on Wordpress from now on. This was due for quite some time now because all the Blogger issues I have been having, and specially the Blogger Beta even sucked more than Blogger, nothing could work with Blogger Beta and this ultimately pushed me to move.

Google BlogSearch Ping Service

2006-10-10T02:56:00.000+05:00

Google Launched the Ping Service for Blogs. I don’t think it makes much of difference for Blogger Blogs as they are immediately indexed and are searchable through Google BlogSearch, but for other blogging engines and individual bloggers it is a good service.

Google Buys YouTube

2006-10-10T02:09:00.000+05:00

So, the speculation which has been around for many days was true. Google finally bought YouTube for $1.65 billion. The price is really shocking considering YouTube only started in February 2005. YouTube growth is really inspirational, in such a short period the company reached to a worth of $1.65 billion with around 20 million visitors per month. Amazing!

More details here

Statue of Yoda !

2006-10-09T14:44:00.001+05:00

Statue of Yoda !
Originally uploaded by aleemkhan.

Dave Winer posted

this picture of Yoda Statue at Lucas Studios. Actually am testing my Flickr

account to post on Blogger Beta

through mail.

Hilarious Comedian !

2006-10-08T17:56:00.000+05:00

Was just watching some videos on MetaCafe and found this one!

Comedy Central Presents - Adam Ferrara - video powered by Metacafe

ASP.NET SiteMap Security Trimings

2006-10-08T03:39:00.000+05:00

It is a general requirement in any ASP.NET application to restrict the site navigation for certain roles and allow access for others. Recently I had to restrict the site map of my application based on the roles but as I was not aware of the available site map trimming settings, I made a similar model myself adding extra attributes to my site map nodes and as I am using a TreeView control for binding to the SiteMapDataSource, I used the TreeView DataBound method to access the SiteMapNode attributes and then checking their permission from the Database.

Fortunately the ASP.NET 2.0 provides trimming of the SiteMapNodes based on the available Roles from the underlying RolesProvider. You need to provide the roles attribute in the SiteMapNode and specify the role to which this note is accessible (* can be used for all roles).

<?xml version="1.0" encoding="utf-8" ?>

</siteMap>

You also need to enable the security trimming settings in the web.config as they are disabled by default.

<system.web>

</providers>

</siteMap>

</system.web>

For More information about the sitemap trimming is available in MSDN here.

Logging User Dynamically in ASP.NET

2006-10-06T15:27:00.000+05:00

The entire authentication and authorization model in ASP.NET 2.0 is quite improved from the previous version. The addition of the new Login Controls and the whole Membership and Roles Management through provider model has really made the entire security architecture easy to use yet extremely customizable.

Last night I was looking for a way to Log-In user automatically (without his password) thorugh my code, actually the scenario is that the user actually logs in from another site and is redirected to my site with the username in the request. Now I have the username, no password and how do I log this user in (or create an authentication token for him). A post from Scott Guthrie came to the rescue. An authentication token for any user even if you do not have him password can be set with

FormsAuthentication.SetAuthCookie(LoggedInUserName, False)

Where LoggedInUserName is the username for which you want to set the authentication token. Now ok I can authenticate the user and log him in but the authorization of my website is set to deny the anonymous user so the user cannot even access the Default.aspx where I actually write the above code for creating a token.

<system.web>

</authorization>

</system.web>

There is a simple workaround to this also as you can specify different authorization for any particular path/location in your website. So the following will allow access to the default page to anonymous users but restrict rest of the site of the logged in user.

<system.web>

</authorization>

</system.web>

</location>

Some good resources about ASP.NET 2.0 Authentication and Authorization and Security on the whole are as follows.

Scott Guthrie Post about ASP.NET 2.0 Security Resources

How To: Protect Forms Authentication in ASP.NET

Explained: Forms Authentication in ASP.NET 2.0

Security Guidelines: ASP.NET 2.0

HTML Legend and Fieldset Tags

2006-10-06T15:05:00.000+05:00

I never used the HTML <Legend> and <Fieldset> until recently when I had to create a GroupBox for the controls on a web page. These tags are really amazing; they create a groupbox with rounded corners with Legend on the top. Actually the ASP.NET Panel control has a GroupingText Property, if you specify this property; the panel renders a field set with GroupingText set as the Legend.

<Legend>HTML Group Box</Legend>

</FieldSet>

Musharraf Daily Show Video Link

2006-09-28T22:01:00.000+05:00

Just Forgot to put the link to the Video on the previous post. Here it is

Musharraf on Daily Show

2006-09-28T21:30:00.000+05:00

President Musharraf appears on the Daily Show and has some good chuckles with Jon Stewart. Well Musharraf seems to be on a real marketing move for the book, a bit too much I guess.

In the Line of Fire

2006-09-27T01:30:00.000+05:00

“In the Line of Fire” by Pervez Musharraf has been released today and already it is promising to be a best seller, well why it shouldn’t be when the President himself has caused sensation about the book by providing controversial excerpts from the book during his recent US visit (even during Bush-Musharraf press conference the book came up). The book is certainly going to earn a fortune for the publishers and Musharraf himself.

I have not read the book, but I would love to read it after all the buzz about the content. However, I have read some reviews and most people believe that the book is definitely ghost written with Musharraf’s insights. Also people believe that book may not be all facts but mostly the views about people and events in Musharraf’s own patriotic and military mind. (I praise him of being a patriot). I also read that the book has really negative views/comments about A.Q Khan and his alleged network of nuclear proliferation, personally I believe like most of the other Pakistanis that the whole A.Q Khan drama was a big cover up from Pakistan government. It’s disappointing though that Musharraf brought all this drama to his book. AQ Khan drama might be true but doesn’t sound realistic because either he is too damn smart and all the Pakistani governments and intelligence during the 90’s were so stupid, or Musharraf and his government has screwed the National Hero really bad.

Overall I am a strong Musharraf supporter (still), he may not be the best option but it’s basically a choice between an arrogant military patriot and a bunch of stupid, illiterate and corrupt politicians, so I go with the patriot.

I’ll try to put down my personal review if I ever get to read the bookJ.

Google Blogs About Ansari !

2006-09-27T00:54:00.000+05:00

Ansari Called Google’s Lary Page from the International Space Station, a long distance calls indeedJ. Google Blog gives some more insight into the communication, meanwhile Ansari continues to Blog about her experience.

WOW! What an Adventure She's Having

2006-09-24T17:01:00.000+05:00

Just saw Anousheh Ansari's Space Blog (She is the space tourist currently on ISS), and read her post which she posted from ISS(International Space Station). Wow ! she seemed to be really enjoying her trip, and who will not ?. Its an adventure of a life time and comes at a cost too ($20 million) ... lol.

Its interesting to read the space experience of an ordinary person and not from the astronomer's perspective. I really wish Space Travel becomes more easy and common (and cheaper :d) in our life times, so maybe then me and Azeem and go on a Trip).... I wish :)

Azeem on Blogs

2006-09-21T22:56:00.000+05:00

Last week when I was in Pakistan, Azeem (my yonger brother) seemed super excited about blogging, he created a blog at blogspot around six months back but never used it actively. This time its good to see him active. I hope he continues, atleast I'll have some good links on history and politics. :)

REUNION of BCSS01 and BCSF01

2006-09-19T03:12:00.000+05:00

Its hard to believe that I am back from the long awaited trip to pakistan, was waiting for this from months and the week passed so fast. Apart from meeting the family after 6-7 months, the good thing about the trip was that I got to attend the first ever REUNION of BCSS01 (my batch) and BCSSF01 (my juniors).

It was a wonderful event, the paticipation was very low from our batch and most of the teachers could not make it but overall it was really wonderful to meet old friends and have a some time together. Its a good start and I really hope this becomes more formal and an official Alumni gathering in the years to come.

Thmbs up to Fahim for floating the idea and all his friends who were involved in making this happen. Another nice thing about this event was that we got a chance to float an idea of a Alumni Sponsored Needy Scholarship for PUCIT students.

Actually I am quite late to blog about this, Fahim has been waiting for haroon and my comments about the event (Haroon does'nt seem to get time to write). Hammad(bunty), Ayaz and Kashif have also written about thier experiences.

I am trying to upload some pictures but this Blogger Picutre Upload is giving me tough time, will upload later.

Apology From POPE

2006-09-18T03:04:00.000+05:00

I just read that POPE In-Person apologized for his earlier address. I think this is very responsible step at this stage. Although Muslim leaders around the world are still outraged and asking for a more direct apology, but personally I think we should not be so outraged in the first place.

Anyway I hope this crisis gets over wihtout any furthur damage.

The POPE Controversy

2006-09-18T02:54:00.000+05:00

Surely the Pope’s comments have outraged Muslims all around the world. Although he quoted a previous conversation from history (did not say the controversial sentences directly) but one cannot say that he quoted this for the mere purpose of proving his point. He could have easily given various other examples about the topic “Religion and Politics” (the actual topic of his complete lecture) from the long and Bloody history of Christianity. So, definitely the western interests are be behind this and this may be another way of causing outrage and frustration among Muslims.

However, I do not understand why we are once again so outraged about this. The POPE is not a Muslim, he definitely does not believe in Prophet Muhammad and I think no Christian Does. Also, he does not believe in Islam nor he should be expected to have any respect for Islam or the Prophet Muhammad. So, the POPE or any other Christian believes something wrong and disrespectful about Islam is not something new, at least for me.

Now some people say, that why don’t the Christians (including the POPE) do not respect our religion and Prophet like we Respect their Religion and Prophet (Hazrat Issa). The answer to this question is that Respecting Christianity is a part of our religion because our religion requires us to believe in Christianity and Hazrat Issa, but Christianity does not require Christians to believe in Islam or the Prophet Muhammad. It is actually the same thing if we analyze how much we respect Hinduism/Buddhism as compared to Christianity because Islam does not requires us to believe in Hinduism or Buddhism. So we do not respect Hinduism and their Gods or their Messengers/Prophet (as they believe) like we respect other religions which are directly mentioned in the Holy Quran.

I do agree completely that according to the current situation of the WORLD, harmony and respect for each other’s religion is very crucial for living together and someone like POPE who influences many should not have given such a controversial example about the 2^nd major religion of the world. If this is the issue that we raise and this is the point we stress on, we stand justified (according to my understanding) and we will be able to convey a valid point to the World, but if we take this emotionally and consider this as an attack on our religion (exactly as we are doing now) and react in the same way we did a few months back with Violence on the streets, we will be letting WEST win and giving them another reason to portray a negative image of our humble Religion Islam.

Portraying a Humble, Noble and a True Image of Islam to the world is our responsibility and this can only be achieved by intelligence, wisdom and tolerance not by mere emotions and burning our own countries.

Yeh! Passed Driving Test

2006-09-04T01:28:00.000+05:00

Today was a great day, early in the morning I passed the driving test for the LMV (Light Motor Vehicle) and got the Driving Licnese. I simply believe that it was due to the grace of Allah. I have failed one before in last month, but even getting License in second attempt is an achievement in Dubai.

Now have to start looking for a good car, but probably after I get back from the visit to Pakistan next week. Yes finally going to Pakistan after 7 months, really excited to meet family & friends there.

Do not believe everything on net !

2006-09-01T02:24:00.000+05:00

Got this cool comic in mail, a good complement to a bulk of the irritating mails on the mailing lists, that people keep forwarding without verification.

Why Collation Affects T-SQL Syntax

2006-08-28T23:27:00.000+05:00

This is something really intersting, atleast for me this is completely new and is still sort of mystery like what’s going on. Today I deployed a SQL Server 2005 Database on one of the test servers at office and during the test my application started crashing. I was getting declaration errors form the database.

“Must declare Variable @ApplicaitonID “

It appeared that all the variables were declared but they were declared in difference a CASE and used in different CASE, well this should’nt be a problem, I have been using T-SQL without case sensitivity for long, but when I corrected the case everything seemed fine. The EXEC master.dbo.sp_server_info returned the following results (given at the end) and you can see the IDENTIFIER_CASE parameter set to SENSITIVE, Actually it should be MIXED. Anyway I tried to find how to change this parameter but it seems that there is no direct way to change it.

This parameter depends on the Collation so apperently there is a problem with the Collation, ok now I have to change the Collation to SQL_Latin1_General_CP1_CI_AS From Latin1_General_BIN. Now chaning collation on the database server is a long hard process, you have backup all your data and tables and reinstall the Database Engine with different collation and restore everything back.

The First thing I do not understand is that why collation is applied on the Variable Names (T-SQL Syntax), I always thought collation was something only for the comaprison/Case-Sensitivity of database data and something which will not be used for procedure compilation. I do not understand this and I’ll have to find some answer for this.

Secondly, SQL Server 2005 supports different collation settings for each database and the Database Engine itself, and the collation settings on the copied database was fine. I even rechecked it and even tried to set it again but still even with the correct collation I continued to get the same Errors, I opened a procedure from database with the correct collation in Management Studio and tried recompiling it, but it was giving a recompilation error because of the case insensitivity. If SQL Server 2005 supports different Collation settings for Server and each individual database why I keep getting this annoying error.

If some can explain this to me I will really appreciate.

EXEC master.dbo.sp_server_info

attribute_id attribute_name attribute_value

------------ ---------------------------- ---------------------------------------

1 DBMS_NAME Microsoft SQL Server

2 DBMS_VER Microsoft SQL Server Yukon - 9.00.1399

10 OWNER_TERM owner

11 TABLE_TERM table

12 MAX_OWNER_NAME_LENGTH 128

13 TABLE_LENGTH 128

14 MAX_QUAL_LENGTH 128

15 COLUMN_LENGTH 128

16 IDENTIFIER_CASE SENSITIVE

17 TX_ISOLATION 2

18 COLLATION_SEQ charset=iso_1 collation=Latin1_General_BIN

19 SAVEPOINT_SUPPORT Y

20 MULTI_RESULT_SETS Y

22 ACCESSIBLE_TABLES Y

100 USERID_LENGTH 128

101 QUALIFIER_TERM database

102 NAMED_TRANSACTIONS Y

103 SPROC_AS_LANGUAGE Y

104 ACCESSIBLE_SPROC Y

105 MAX_INDEX_COLS 16

106 RENAME_TABLE Y

107 RENAME_COLUMN Y

108 DROP_COLUMN Y

109 INCREASE_COLUMN_LENGTH Y

110 DDL_IN_TRANSACTION Y

111 DESCENDING_INDEXES Y

112 SP_RENAME Y

113 REMOTE_SPROC Y

500 SYS_SPROC_VERSION 9.00.1399

(29 row(s) affected)

Meda Ishq Wi Toon, Meda Yaar Wi Toon

2006-08-28T22:37:00.000+05:00

What a classic from Pathanay Khan, but you must have some sort of taste for classical music. 17 minutes of amazing voice and music ! ........ took most of the days pressure off my mind.

History of Programming Languages

2006-08-26T03:32:00.000+05:00

I have posted this link before, but just saw this nicely formatted and colored version from O'Reilly.

http://www.oreilly.com/news/graphics/prog_lang_poster.pdf

Getting in touch with Old Colleagues

2006-08-26T01:05:00.000+05:00

I go thorugh various blogs, but I thought I should atleast have links to all the Bloggers I personally know, from work, university, old friends even college etc, so its easier to get in touch and see whats going on with them.

I keep loosing this one guy Haroon Shafiq, my Senior from University. I found his blog in december last year, but now when I open the link I get some advertisement site.

I tried to find him and found another of his blogs here http://my.opera.com/vodkamilkshake/blog/, does'nt seem to be his active blog, only 2 posts.

BTW one of the post had an ineteresting story.. lol ...

CSS Background-Image Property Unsupported in XP

2006-08-25T14:59:00.000+05:00

Was just working on interface of my application last night, and had to make few changes for background of buttons. I used background-image CSS property for setting the images for my buttons, everything looked fine untill I tried to access the application on Windows XP. Oh ! no background is displayed on XP.

Interestingly its a known Bug in Internet Explorer 6.0 which uses windows XP themes to render its controls, now thre are a couple of solutions to this, one is to use background istead of background-image and other is to include this

to disable XP themes on the page.

http://support.microsoft.com/default.aspx?scid=kb;en-us;322240&Product=winxp

Google Strategy !

2006-08-25T14:45:00.000+05:00

Just read something Interesting about Google Strategy.

Marc Canter has an interesting post about the strategy of google, and how Google is trying to "lock-in" the end-users/developers by using and following thier own proprietary protocols (developed based on open protocols) but not completely open something what Microsoft did through 80's and 90's.

Also check the Mouse Trap Post by Chris Messina on the same topic, but as Rebert Scoble pointed out it would be nice to hear what Google Says about this.

Peronsally I haven't seen many Google Blogs !

Salor System Looses a Planet

2006-08-24T21:15:00.000+05:00

According to awaited decision of International Astronomical Union, Pluto is no longer a planet and will be classified in a new term "dwarf planet". The Solar System will now have total of 8 Planets.

Other celestial objects in our Solar System like Ceres and UB313 (Xena) which were highly expected to be declared planets will also remain in the "dwarf planet" category. Pluto's moon Charon remains without a category and is not classified at the moment.

http://www.cnn.com/2006/TECH/space/08/24/pluto.ap/index.html

Space Elevator

2006-08-23T21:49:00.000+05:00

I was just going throuh some of the space articles and found about the Concept of Space Elevator. I have seen many fictitious concepts about space but what amazes me about the concept of a Space Elevator is that it is theoratically not only possible but companies are actually working on the concept and NASA seems really interested too.

Anyway this is understandable that it is not something that is going to happen in 10 years but maybe after 50 years you may actually have a trip to space in a Elevator suspended from earth ! . The Concept is pretty simple, if you tie a thread on a side of a rotating ball with a small counterweight on the other side of the thread, due to the centrifugal force produced by the rotating ball, the thread will strat revolving with the ball and will seem as a suspended rope from the surface of the ball.

So if a 62,000-mile (100,000-kilometer) rope is suspended from the earth into space with a couterweigt attached on the other side of the rope, it will start spinning becuase of the centrifugal force of the earth, now if this rope is strong enough an Elevator Car can be attached to to it and can be used for transportation.

However, this rope cannot be directly attached to surface of the earth, but can suspended through a non-stationary plaform like an oil rig in the sea so it has some margin for movement becuase of winds and other hazards. The major hurdle in such a design was the availability of a material string enough for the rope, but now with Carbon Nanotube (discovered in 1991, 100 times stronger than steel and 1/5 in weight, a single thread of Nano Tube can easily support a full Saloon car) the material to build the Elevator is available.

Anyway It's an extraordinary idea indeed

Celebrity Look-Alikes

2006-08-21T19:58:00.000+05:00

Fahim posted about the My Heritage Face Recognition and how he got very different results with different images. I also tried with one of my images ans I observed that it has largely different results even with the same image when it is flipped, or even slightly changed. I believe the face recognition agorithm they are using is not extracting the features of the face but only comparing with the complete face, otherwise flipping the face should not made such a big difference.

Here are the two results.

Windows Live Writer

2006-08-21T02:30:00.000+05:00

I have been looking for a better soltuion for writing Blogs offline, Blogger does allow me to send Blog through mail but for images I always have to go through a lot of trouble for uploading images. I was just seeing the Fahim's Blog and found this post about Windows Live Writer (actually most of his posts are intersting), its just I was already looking for a Blog Writer.

It's nice but unfortunately still does'nt work with the images. I think it is more of a Blogger Issue, it has a wiered way of supporting images. I am really considering shifting to wordpress, blogger is getting too far behind on the all features other blog services are providing.

Views of British Parliament Member on Isreal/Lebanon War

2006-08-07T20:43:00.000+05:00

Listen to views of George Galloway, a British Parliamentarian about the Israel/Lebanon War. I believe every moral person related to any religion would find his views straight forward, absolutely true and just. However most of the world continues to pretend that this injustice in Middle East is not their problem. Unfortunate!

http://www.informationclearinghouse.info/article14391.htm

T-SQL Error Handling Pattern ( For Nested Transactions And Stored Procedures)

2006-07-21T16:44:00.000+05:00

Error Handling has always been cumbersome in SQL server, with all the unstructured @@Error checks scattered all around the place, this makes the T-SQL code harder to read and many errors go unaddressed due to simple coding mistakes. SQL Server 2005 comes to the rescue with the new TRY…CATCH block, but it is important how the try catch block is used. Also, recently I have had many issues with the Nested Transactions and the Nested Stored Procedures each using its own transaction.

The issues I am referring to are the things like the TRANCOUNT check on the entry and exit of each stored procedure. For example you are in a stored procedure which is called by another outer procedure (both using BEGIN TRAN), when you call Rollback in the second procedure, SQL Server will throw the following error on the exit of the second procedure and will leave the transaction is a unconsistent state

"Transaction count after EXECUTE indicates that a COMMIT or ROLLBACK TRANSACTION statement is missing. Previous count = 1, current count =0. "

Similarly, as I mentioned in a previous post a single ROLLBACK will set the @@TRANCOUNT to zero and any subsequent ROLLBACK in an outer procedure will give the following error

"The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION."

Infact, all these small things are very trivial in T-SQL and there are several ways to solve them, for example some people try not to use the transactions at database at all, they take the TRANSACTION Management completely to their data layer and manage it through MTS. (This was the case in one of the projects I worked on last year). Similarly, some people would always take care that Transaction is being used in only the outer procedure which is to be called by the data layer etc. However, this can easily break if you are not in control of all the T-SQL code you are writing,like if you have an encrypted third-party stored procedure, you wouldn’t know if it calls the ROLLBACK/COMMIT which may break your logic in the outer procedure.

There should be some standard pattern for the Error Handling and writing standard stored procedure, and especially with the availability of the new Error Handling features in SQL Server 2005. So, I came up with the following Pattern for a standard stored procedure using an independent transaction. This stored procedure will not break on the behavior of the procedure it calls and is returning the error messages to its caller in a standard way (RAISERROR)

ALTER PROCEDURE [dbo].[StandardTSQLProcedure]
AS

BEGIN TRY

DECLARE
@TranStarted bit
SET @TranStarted = 0

IF( @@TRANCOUNT = 0 )
BEGIN
BEGIN TRANSACTION
SET @TranStarted = 1
END
ELSE
SET @TranStarted = 0

-------------------------------------------------------
--Your Standard T-SQL Code for the Procedure Comes Here

-------------------------------------------------------

IF( @TranStarted = 1 )
BEGIN
SET @TranStarted = 0
COMMIT TRANSACTION
END

RETURN(0)

END TRY

BEGIN CATCH
DECLARE @ErrorMessage NVARCHAR(4000);
DECLARE @ErrorNumber INT;
DECLARE @ErrorSeverity INT;
DECLARE @ErrorState INT;

SELECT @ErrorMessage = ERROR_MESSAGE(),
@ErrorSeverity = ERROR_SEVERITY(),
@ErrorState = ERROR_STATE(),
@ErrorNumber = ERROR_NUMBER();

IF( @TranStarted = 1 )
BEGIN
SET @TranStarted = 0
ROLLBACK TRANSACTION
END

RAISERROR (@ErrorMessage, @ErrorSeverity, @ErrorState);
END CATCH

WinFX Renaming to .NET 3.0

2006-07-21T14:42:00.000+05:00

Check out this Channel9 video with Jason Zander on the renaming of WinFX to .NET 3.0 and what it contains. He has tried to remove the confusion with a nice diagram explaining different technology stacks and their relationship to each other.

Javascript Function to get control using Server Side ID

2006-07-19T01:57:00.000+05:00

I don’t remember how many times I have written this, nearly for every ASP.NET project I have to write this, so I am posting so I can get it back. It is a simple method of the getting the control with the server side id. ASP.NET changes the Id’s of nested server side controls when page is rendered.

This function simply compares the last part of the control id with the server side id of the control (passed as parameter)

function findObjWithClientId(Id)

{

var ctrls = document.all;

for(var count = 0; count < ctrls.length ; count ++)

{

var index = ctrls[count].id.indexOf(Id);

if(index != -1)

{

if((ctrls[count].id.length - index) == Id.length)

{

return ctrls[count];

}

return null;

}

Limitations of the XML Data Type in SQL Server 2005

2006-07-17T11:10:00.000+05:00

Although the XML datatype is treated like many other datatypes in SQL Server 2005, there are specific limitations to how it is used. These limitations are:

XML types cannot convert to text or ntext data types.
No data type other than one of the string types can be cast to XML.
XML columns cannot be used in GROUP BY statements.
Distributed partitioned views or materialized views cannot contain XML data types.
Use of the sql_variant instances cannot include XML as a subtype.
XML columns cannot be part of a primary or foreign key.
XML columns cannot be designated as unique.
Collation (COLLATE clause) cannot be used on XML columns.
XML columns cannot participate in rules.
The only built-in scalar functions that apply to XML columns are ISNULL and COALESCE. No other scalar built-in functions are supported for use against XML types.
Tables can have only 32 XML columns.
Tables with XML columns cannot have a primary key with more than 15 columns.
Tables with XML columns cannot have a timestamp data type as part of their primary key.
Only 128 levels of hierarchy are supported within XML stored in the database.

GO Vertscape!

2006-07-17T02:34:00.000+05:00

Vertscape Infotech (our company) won 3 awards at the Microsoft Partner Conference this year. The awards are as follows

Technology Innovation Partner of the Year
Winning Customer Award (Application Platform - .NET)
CRN Technology Innovation Partner of the Year

See the results here

http://www.microsoft.com/Partner/events/wwpartnerconference/awards_finalists.htm

Nested T-SQL Transactions

2006-07-12T11:31:00.000+05:00

Recently, I had an issue with nested transaction in SQL Server, pretty simple thing but I realized that I was'nt taking care of this for most of the T-SQL code I write. Fortunately, never had a problem but I thought I shoud post about this so I could remeber this.

Try running the following T-SQL code in SQL Server

BEGIN TRANSACTION
BEGIN TRANSACTION
-- Some Code
ROLLBACK TRANSACTION
ROLLBACK TRANSACTION

This code simpley throws an error "
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION". Hey thats strange, I have two BEGIN statements so a I need a couple of ROLLBACKS to Roll them back, it seems logical but actually its not.

Transaction are managed in SQL Server through a transaction count, each new BEGIN TRAN statement adds one to the TRAN Count, and a single Rollback rightly makes the TRAN Count zero, so everything is Rolled back with one Rollback.

I can definately take care of this in my own code, but what happens if I am using a third party proceudre which ROLLBACKS the transaction, how do I know I have to put a ROLLBACK in my own code or not. If an encrypted third party procedure calls Rollback before my code, my procedure will throw error when it calls its Rollback.

The Best Pattern to do this is to use the @@TRANCOUNT variable before EACH ROLLBACK, so the the way ROLLBACK should be called is

IF @@TRANCOUNT > 0
BEGIN
ROLLBACK
END

Neat thing to learn !

SQL Server 2005 Management Studio

2006-07-08T16:01:00.000+05:00

Recently, working in the SQL server Management Studio, I spent a couple of hours searching for the Stored Procedure Debugging. As the Management Studio replaces both Query Analyzer and Enterprise Manager from the previous version of the SQL Server Tools, it is very common to assume that there must be some Debugging option available in the new Management Studio.

However there isn’t any, and you need Visual Studio 2005 for stored Procedure Debugging, this is not only for the SQL-CLR procedures written in a .NET language but even for the T-SQL Procedures. You need to connect the “Server Explorer” to the SQL Server, select your procedure and on right click you will find the “Step Into Procedure” option which will let you step into the procedure for debugging.

Pretty easy, if you know to debug with Visual Studio in the first place, but there are issues with the remote debugging. You need to check if the Remote Debugging Service is running on the server and you need to have the network credentials for the server, preferably your account should be a member of server administrators group.

So, finally after wasting half day, I got everything working.

:)

WinFS Scrapped! What's Left of Vista

2006-06-29T01:39:00.000+05:00

Windows Vista which Microsoft promised as the Operating System that will change computing is already in uncharted waters even before its over-delayed release, and now abandoning the WinFS Project is like the last nail in the grave for Vista.

WinFS Team announced that they are not going to deliver WinFS and the research and ““innovation”” will be handed to the SQL-Server and ADO.NET teams and may appear into the next versions of both products.
http://blogs.msdn.com/winfs/archive/2006/06/23/644706.aspx

It is hard to imagine how an organization as prominent as Microsoft can get away with such a failure. Vista has been their major focus for more than 5-6 years; they have over 2000 people on Vista alone. WinFS to me seemed to be the strongest pillar of Vista after Indigo.

Recently a lot has been coming out of Microsoft about bad project management and other issues especially on the Vista Project. Philip Su in the Vista team http://blogs.msdn.com/philipsu/archive/2006/06/14/631438.aspx explains why Vista is slipped so late mostly due to management issues.

Scobleizer leaving Microsoft

2006-06-16T18:20:00.000+05:00

I just heard the news that Scobleizer is leaving Microsoft, his blog and Channel has always been a great source about what’s happening inside Microsoft. I wonder if he will still continue to work at Channel 9.

http://news.bbc.co.uk/2/hi/technology/5070940.stm

Now Running Windows Vista !

2006-06-01T20:24:00.000+05:00

Installed Windows Vista Beta 2 on my HP nc6120 Notebook, just having fun with the UI at the moment, have'nt gone down to checking development experience. I was surprised to run it almost without any trouble. I thought driver issues and performance will really give me trouble, but it automaticlly adjusted to the graphics capability of my system and I had to install not a single driver.

The Features which could not be supported by my modest built-in 915 Intel Chip Graphic Card were automatically diabled like the 3D Flip View to toggle windows.

I installed Beta 1before this, but that could run nothing, finally Beta 2 seems to be stable enough to give me a good experience.

Its beta and everyone expects issues, infact i saw a few menus features which were not working but still I should say that substantial work has been done in Vista, atleast from the appearance point of view. A lot of basic tasks are rearranged from the older version of windows.

Have a look at some of the Screen shots.

Disable/Enable Dialog Box in Windows

2006-06-01T13:36:00.000+05:00

One of the things I really miss and loved working with was Win32, not that I am of the view that is flawless, but the control that I have over my application when I am writing code is awsome. Ofcourse, all .NET abstraction has countless advantages and is definately the future, but ocassionally its always nice to dig back to bottom.

Recently someone asked this on microsoft.public.dotnet.csharp.general newsgroup, that if you are calling a library function .NET which is some Dll, and is showing a MessageBox on some error or a "Trial" Message etc, how you would Supress/Hide that Message Box in .NET.

I wrote this following class DisableModalDialog to do the exact thing. To use the class see the following click event to see how u can disable/enable dialog boxes.

private void button1_Click(object sender, System.EventArgs e)
{
DisableModalDialog dmd = new DisableModalDialog();

dmd.DisableMessageBox();

MessageBox.Show("Hello");
MessageBox.Show("Hello");
MessageBox.Show("Hello");
MessageBox.Show("Hello");
MessageBox.Show("Hello");
MessageBox.Show("Hello");

dmd.EnableMessageBox();

}

// Class to Enable/Disable Windows Dialog Boxes
// NOTE : This Class Will Only Disable Dialog Boxes in Current Thread
public class DisableModalDialog
{
// Constructor
public DisableModalDialog() {}

public void DisableMessageBox()
{
this.myCallbackDelegate = new HookProc(this.MyHookCallbackFunction);
hHOOK = SetWindowsHookEx(HookType.WH_CALLWNDPROC, this.myCallbackDelegate, IntPtr.Zero, (uint)AppDomain.GetCurrentThreadId());
}

public void EnableMessageBox()
{
UnhookWindowsHookEx(hHOOK);
}

private IntPtr hHOOK;
private IntPtr OrigDlgProc;

private HookProc myCallbackDelegate = null;
delegate int HookProc(int code, IntPtr v1, IntPtr v2);

private CustomWindowProc myCallBackWndProcDelegate = null;
delegate IntPtr CustomWindowProc(IntPtr hwnd,uint uMsg,IntPtr wParam,IntPtr lParam);

[DllImport("user32.dll")]
private static extern IntPtr SetWindowsHookEx(HookType hook, HookProc callback,
IntPtr hMod, uint dwThreadId);

[DllImport("user32.dll")]
private static extern IntPtr UnhookWindowsHookEx(IntPtr hhk);

[DllImport("user32.dll")]
private static extern int CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

[DllImport("user32.dll")]
private static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, CustomWindowProc dwNewLong);

[DllImport("user32.dll")]
private static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);

//[DllImport("user32.dll")]
//private static extern IntPtr SetClassLong(IntPtr hWnd, int nIndex, CustomWindowProc dwNewLong);

//[DllImport("user32.dll")]
//private static extern IntPtr DefWindowProc(IntPtr hWnd, uint Msg, IntPtr wParam,IntPtr lParam);

[DllImport("user32.dll")]
private static extern IntPtr DefDlgProc(IntPtr hDlg, uint Msg, IntPtr wParam,IntPtr lParam);

private enum HookType : int
{
WH_JOURNALRECORD = 0,
WH_JOURNALPLAYBACK = 1,
WH_KEYBOARD = 2,
WH_GETMESSAGE = 3,
WH_CALLWNDPROC = 4,
WH_CBT = 5,
WH_SYSMSGFILTER = 6,
WH_MOUSE = 7,
WH_HARDWARE = 8,
WH_DEBUG = 9,
WH_SHELL = 10,
WH_FOREGROUNDIDLE = 11,
WH_CALLWNDPROCRET = 12,
WH_KEYBOARD_LL = 13,
WH_MOUSE_LL = 14
}

[StructLayout(LayoutKind.Sequential)]
private struct CWPSTRUCT
{
public IntPtr lparam;
public IntPtr wparam;
public int message;
public IntPtr hwnd;
}

//private static int WM_CREATE = 0x0001;
//private static int HC_ACTION = 0;
//private static int GCL_WNDPROC = (-24);

private static int GWL_WNDPROC = (-4);
private static int WM_INITDIALOG = 0x0110;
private static int WM_SHOWWINDOW = 0x0018;
private static int WM_CLOSE = 0x0010;

// Hook Function to Hook Current Thread Messages
private int MyHookCallbackFunction(int code, IntPtr wParam, IntPtr lParam)
{
CWPSTRUCT cwpStruct = (CWPSTRUCT)System.Runtime.InteropServices.Marshal.PtrToStructure(lParam,typeof(CWPSTRUCT));
if(cwpStruct.message == WM_INITDIALOG)
{
myCallBackWndProcDelegate = new CustomWindowProc(this.MyCustomDialogProc);
this.OrigDlgProc = (IntPtr) SetWindowLong(cwpStruct.hwnd, GWL_WNDPROC, this.myCallBackWndProcDelegate);

}
return CallNextHookEx(IntPtr.Zero, code, wParam, lParam);
}

// Custom Dialog Procedure for Handling Dialog Messages
private IntPtr MyCustomDialogProc(IntPtr hwnd,uint uMsg,IntPtr wParam,IntPtr lParam)
{
if(uMsg == WM_SHOWWINDOW)
{
SetWindowLong(hwnd,GWL_WNDPROC, this.OrigDlgProc);
uMsg = (uint) WM_CLOSE;
}

return DefDlgProc(hwnd,uMsg,wParam,lParam);
}
}

Back to Blogging !

2006-06-01T12:48:00.000+05:00

Its been a while since I have been here, over the last few months a lot of things were changing and I had to settle down to start all this stuff. The Major change is that I joined Vertscape Infotech and have planned to settle here in Dubai, atleast for a few years.

Also, I wanted to get back to blogging with a new spirit :), so I have been looking at various other options for blogging like wordpress.com which provides with additional content pages. Infact I was working on a personal blog site, but it was taking more time than I initially thought so I got out of it. I tried wordpress but it lacks the HTML edit like the Blogger which gives me total control over my Blog.

So, I am sticking to Blogger and hoping they'll add support for aditional content pages soon. Anyway to live up to the new spirit I changed the template for my Blog. I liked the Luxinterior Dark Template of the Community Server, but this one is even better.

This template is originally developed by Nikhil Kothari for his website http://www.nikhilk.net , Someone has developed this for Community Server also, anyway I took the template and changed it for Blogger.com. I think its really nice and specially the page transition effect. :)

Cheers!

AJAX Design Patterns !

2006-03-26T02:10:00.000+05:00

Some Cool links for AJAX patterns,

http://blogs.msdn.com/ricksp/archive/2006/03/23/559445.aspx

http://blogs.msdn.com/brada/archive/2006/03/23/559077.aspx

http://www.baekdal.com/articles/Usability/XMLHttpRequest-guidelines

http://softwareas.com/ajax-patterns

Why is Programming Fun !

2006-03-21T00:02:00.000+05:00

I just started the book, “The Mythical Man Month: Essays on Software Engineering”, have only been through the first chapter and I think I have never read such a wonderful few paragraphs, written in non-techncial language and tone and yet commenting on the most technical and complex issues of Software programming and devlopment. Absolutely Classical !

The Joys of the Craft

Why is programming fun? What delights may its practitioner expect as his reward?

First is the sheer joy of making things. As the child delights in his mud pie, so the adult enjoys building things, especially things of his own design. I think this delight must be an image of God's delight in making things, a delight shown in the distinctness and newness of each leaf and each snowflake.

Second is the pleasure of making things that are useful to other people. Deep within, we want others to use our work and to find it helpful. In this respect the programming system is not essentially different from the child's first clay pencil holder "for Daddy's office."

Third is the fascination of fashioning complex puzzle-like objects of interlocking moving parts and watching them work in subtle cycles, playing out the consequences of principles built in from the beginning. The programmed computer has all the fascination of the pinball machine or the jukebox mechanism, carried to the ultimate.

Fourth is the joy of always learning, which springs from the nonrepeating nature of the task. In one way or another, the problem is ever new, and its solver learns something: sometimes practical, sometimes theoretical, and sometimes both.

Finally, there is the delight of working in such a tractable medium. The programmer, like the poet, works only slightly removed from pure thought-stuff. He builds his castles in the air, from air, creating by exertion of the imagination. Few media of creation are so flexible, so easy to polish and rework, so readily capable of realizing grand conceptual structures. (As we shall see later, this very tractability has its own problems.) Yet the program construct, unlike the poet's words, is real in the sense that it moves and works, producing visible outputs separate from the construct itself. It prints results, draws pictures, produces sounds, moves arms. The magic of myth and legend has come true in our time. One types the correct incantation on a keyboard, and a display screen comes to life, showing things that never were nor could be.

Programming then is fun because it gratifies creative longings built deep within us and delights sensibilities we have in common with all men.

The Woes of the Craft

Not all is delight, however, and knowing the inherent woes makes it easier to bear them when they appear.

First, one must perform perfectly. The computer resembles the magic of legend in this respect, too. If one character, one pause, of the incantation is not strictly in proper form, the magic doesn't work. Human beings are not accustomed to being perfect, and few areas of human activity demand it. Adjusting to the requirement for perfection is, I think, the most difficult part of learning to program.

Next, other people set one's objectives, provide one's resources, and furnish one's information. One rarely controls the circumstances of his work, or even its goal. In management terms, one's authority is not sufficient for his responsibility. It seems that in all fields, however, the jobs where things get done never have formal authority commensurate with responsibility. In practice, actual (as opposed to formal) authority is acquired from the very momentum of accomplishment. The dependence upon others has a particular case that is especially painful for the system programmer. He depends upon other people's programs. These are often maldesigned, poorly implemented, incompletely delivered (no source code or test cases), and poorly documented. So he must spend hours studying and fixing things that in an ideal world would be complete, available, and usable.

The next woe is that designing grand concepts is fun; finding nitty little bugs is just work. With any creative activity come The Woes of the Craft dreary hours of tedious, painstaking labor, and programming is no exception.

Next, one finds that debugging has a linear convergence, or worse, where one somehow expects a quadratic sort of approach to the end. So testing drags on and on, the last difficult bugs taking more time to find than the first.

The last woe, and sometimes the last straw, is that the product over which one has labored so long appears to be obsolete upon (or before) completion. Already colleagues and competitors are in hot pursuit of new and better ideas. Already the displacement of one's thought-child is not only conceived, but scheduled. This always seems worse than it really is. The new and better product is generally not available when one completes his own; it is only talked about. It, too, will require months of development. The real tiger is never a match for the paper one, unless actual use is wanted. Then the virtues of reality have a satisfaction all their own.

Of course the technological base on which one builds is always advancing. As soon as one freezes a design, it becomes obsolete in terms of its concepts. But implementation of real products demands phasing and quantizing. The obsolescence of an implementation must be measured against other existing implementations, not against unrealized concepts. The challenge and the mission are to find real solutions to real problems on actual schedules with available resources.

This then is programming, both a tar pit in which many efforts have floundered and a creative activity with joys and woes all its own.

For many, the joys far outweigh the woes.

Taken from “The Mythical Man Month: Essays on Software Engineering”

Google Earth is Cool !

2006-03-19T02:00:00.001+05:00

Google keeps on adding details to new places and cities around the world on Google Earth, I think its extremely wonderful. I was just seeing Islamabad and was finding old places, like our old house and other places in Islamabad. After the recent Earth Quake in the Northern areas of Pakistan, most northern cities are updated. Take a look at the details .......

Google Earth (Our old House, Islamabad)

Google Earth (Sports Complex, Islamabad)

2006-03-19T02:00:00.000+05:00

Google Earth (Sports Complex, Islamabad)

Google Earth (Demolished Building/Earth Quake, Islamabad)

2006-03-19T01:59:00.000+05:00

Google Earth (Demolished Building/Earth Quake, Islamabad)

Google Earth (Presidency, Islamabad)

2006-03-19T01:56:00.000+05:00

Google Earth (Presidency, Islamabad)

Google Earth (Faisal Mosque, Islamabad)

2006-03-19T01:47:00.000+05:00

Google Earth (Faisal Mosque, Islamabad)

@ Airport !

2006-02-28T00:28:00.000+05:00

Just getting ready to board for Lahore, the boarding will start on 11:45. Never thought will be using Internet from the Airport, was just getting bored sitting near the Duty Free here at the Airport and turned on my laptop and it connected to the Airport Wireless Broadband, so good way to pass time. I should get going, boarding time is getting close.

Going to Pakistan ! :)

2006-02-27T18:36:00.000+05:00

Today I am flying back to Pakistan; it’s been 3 months in Dubai and my record for living away from home this long. It’s a short trip probably 5-6 days but I think it’ll be relaxing. I can’t wait to reach. Life in Dubai has been good but living with family has its own charm which u cannot get anywhere. Ok I should start packing, have to leave for Airport in a couple of hours.

Bye !

SqlDataSourceEnumerator

2006-02-27T18:29:00.000+05:00

I was just working on a small application in Visual Studio 2005, I am using the SqlDataSourceEnumerator which is new in Framework 2.0 and enumerates all the instances of SQL Server 2000 and SQL Server 2005 on the network, following is my function from my class.

The interesting thing is that SqlDataSourceEnumerator does enumerates all servers including the SQL Server on my local machine when I am connected to the network, but if I am not connected to a network, it does not even get my local SQL Server. This is quite strange, because even if the API it works for the network it should check the loopback (127.0.0.1) network.

I know I can solve this by using the SQLDEMO API’s to get the SQL Servers as we have been doing in 1.1, but still am looking for the answer for the behavior of SqlDataSourceEnumerator

public string[] GetAllServerNames()

{

ArrayList array = new ArrayList();

SqlDataSourceEnumerator dse = SqlDataSourceEnumerator.Instance;

DataTable dt = dse.GetDataSources();

foreach (DataRow dr in dt.Rows)

{

array.Add(dr["ServerName"]);

}

return (string[])array.ToArray(typeof(string));

}

A Software Woe !

2006-01-15T14:23:00.000+05:00

Help ! Help !

Somebody get me some pirated software, I never knew finding the software can be so hard, before coming here.

Once upon a time I read an article "In the Beginning was the Command Line", there was a line at the start of Article

"Its Interesting, rather Unbelievable that the RICHEST person in the World is not an OIL TYCOON or some Owner of a LARGE INDUSTRY, but has earned his fortune with something (SOFTWARE) which actually has no physical existence of its own."

Now I got the real meaning of it, when I am really seeing PPL giving more MONEY for Software than the Taxes they give to the government. :)

Personally, I am still SPLIT on the notion of Software Being Free or Not; I know there are Linux Sensitive guys on this group (who will definitely answer), but in reality Open Source Development does not provide the quality and comfort that the paid software gives, some may not agree but its not always about learning programming problems or resolving technical issues, though I must mention Mozilla Browser being the only recent thing worthy of calling itself an end-user product.

In Professional environments you just need to get things done as soon as possible and you just don’t want to keep spending time on resolving small technical issues and experiencing the sense of achievement that you are a great programmer and can still resolve problems which are harder to solve. And of course, as they say

“Linux is for Programmers, and then let Programmers have it” J

On the other side, I have doubts about the closed software model that companies like Microsoft has. Cost is one big issue which has made companies crazy and instead of increasing their profits through increased software productivity, they actually go on spending millions on purchasing and development of solutions. Also, I believe that keep on changing products and bringing new versions of the software (without substantial changes) only serves in teasing the customers, and I don’t like innovation and product development which is driven by an aim to earn more money. (Like Microsoft)

May be all this should not be a debate after all; it’s about what works best for you.

Caution!

-------------

If you ever plan to leave the COUNTRY for some time, please do take most of the Softwares you need on a CD/HardDisk along with you,

Otherwise, most likely you'll be handing over all that you owe to EVIL SOFTWARE COMPANIES (does not only include Microsoft).

January 8th, 2006

2006-01-08T01:51:00.000+05:00

Today I bought my new HP nc6120 Notebook. It is Centrino 1.73, 512 MB RAM and 60G Hard Disk and Windows XP Professional. Actually, I had an option between the ACER 5202, but most people recommend HP especially for professional use. I think I’ll be able to utilize my time in something better now, the learning was stopped from last once month since I have come to Dubai. Also, I will be able to communicate with the family more frequently now. May Allah let me use this good purposes and for increasing my knowledge.

Ok I’ll let you guys see it J

Last Day of 2005 (Memories/Thoughts) !

2005-12-31T19:30:00.000+05:00

And here we are on the last day of 2005. It was a good year, I do have some targets set for 2006, but I am not going to make them public J

The atmosphere here in Dubai is a little windy today, a light cool breeze.

A couple of days ago I found Haroon Shafiq’s Blog (added that to my recommended Blogs Section), it was good to find him, he is really a gr8 guy and has a wonderful Blot too, his Blog took me to Worst Tech Moments in 2005. Interesting happenings, especially I found a few of them quite interesting, like

US Commerce Department blocks .xxx domain
A narrow escape from the repetition of Columbia Disaster [NASA Story]
Yahoo Helps China Imprison a Dissident

Though I myself support the decision of US Commerce department regarding the blocking of .xxx domains, but still it is depressing to know that Internet content and Domain system is under the influence (*control*) of a government and specially with Mr. Bush leading that government, highly degrades my confidence while using the internet L. However, the most depressing is what Yahoo! Did, I never knew my mails were not safe, I think the private policy does not say anything like this, our content, communication and mail nothing has any privacy. I can only say this

“We are not culturally and morally developed to use the technologies and inventions that we have created.”

The Limits of Technology

2005-12-15T14:21:00.000+05:00

Wow !

One of my colleagues gave me this link to a wonderful article by Grady Booch.
http://www-128.ibm.com/developerworks/rational/library/2082.html

Great article and true analysis of the software design/development, and its limitations and problems.

Also, while reading Occam's Razor in the article, I researched on it a bit on Wikipedia and found what it really meant "Entities should not be multiplied unnecessarily", I remeber Occam's Razor from the Judy Foster's Film Contact, but did'nt know the exact meaning.

Also, liked the Newton's and Eienstien's illustrations of the same phrase

"We are to admit no more causes of natural things than such are both true and sufficient to explain their appearances." -- Issac Newton

"Everything should be made as simple as possible, but not simpler" -- Albert Eienstien.

Anyway, a good and useful reading.

Customizing Properties for .NET PropertyGrid

2005-12-08T11:09:00.000+05:00

I just thought the following conversation could be useful to others as well.

The .NET PropertyGrid Control is a wonderful control which enables you to load any object (or set of objects) in it and displays/exposes all the public properties of the object through reflection. The Framework class library provides various Attributes and Classes to cutomize the way your proerties look. Generally, when you need to customize the way your properties look in the property Grid, either you use the TypeConverters or you create a new Cusotm Editor for your properties. Let me explain this further,

No.1 - Custom Editors for Properties

You must have used a Collection Editor, if your class contains a collection property then visual studio shows a button in-front of the colle ction property and clicking that opens a new dialog in which you can add/edit collection items.

No.2 - Using TypeConverters for Properties

You must have seenn a Font Property in various controls, this property as you see is expandable and then with all the combination of the selected values you can actually show the Font Property, also you must have seen the Icon Property which shows an Icon Image in-front of the property or there are certain properties which show a drop-down in-front of property, these properties use the TypeConverters. There are various type converters available in System.ComponentModel namespace.

I have written some code using the type converters which nearly solves your problem, but the problem with the type converters is that they always update the property after the value has been entered, I mean you won't be able to update it character by character as you want in your case. You will only be able to convert your property value into '**********' after teh full property has been entered. Consider you have the following class which contains public properties which are to be shown in the property Grid.

public class NewClass

{

private string _text;

//Add this Attribute to Specify the TypeConverter

[TypeConverter(typeof(CustomPassConverter))]

public string Text

{

get

    {

      return _text;

    }

    set

    {

      _text = value;

    }

}

}

Look above and see the Attribute that I am using on the Property, this attribute specifies that the CusotmPassConeverter, is the converter to be used for this property. Let me implement the CusotmPassConverter now.

public class CustomPassConverter : System.ComponentModel.StringConverter

{

public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)

{

    string passValue = (string) value;

    string pass = new string('*',passValue.Length);

    return pass;

}

}

Now when you will load this class in the PropertyGrid, and edit the value of the property, after editing the value your value will be changed in '***********'.

I have also tried using the UITypeEditor, which is one of the editors which allows you to draw in the Property and has a PaintValue method, but it has the same problem that it modifies the property after it has been edited.

IF AN EXACT SOLUTION IS POSSIBLE

I beleive that I can always go the old Win32 way. I can write a CustomPropertyGrid Control by inheriting from the original PropertyGrid control overrideing its WndProc, searching for messages and then can do anything. BUT this solution will not work in case for Visual Studio as it is not using my Custom Control.

Yes the correct solution is possible in one way, you can write a custom editor dialog like the Collection Editor Dialog we talked ablut above, let the user enter the Password in that custom dialog (Collection Editor also allows that). Actually when you write a separate dialog as an editor you have complete control over it. So its better to Implement a Custom Dialog. I'll try to write this if I get some extra time.

Regards,

Abdul Aleem

Senior Software Engineer

KalSoft (Pvt) Limited

Dubai, UAE

Cell: +971-502196733

______________________________________________________________

fakhar siddiqui <fakhar_83@yahoo.com> wrote:

Hello,

Its me Fakhar. I am facing some problem in C# when using Property Grid. If u people used Property Grid then u obviously know the properties which we define in our class are mapped to Property Grid after storing the object of that class in PropertyGrid .

The Problem is that I have property in my Class named Password. I want when user will edit that field in property grid it should display * instead of the character which is typed. I think attributes in namespace [using System.ComponentModel] may help. But I could not find any solution.

If you can help me in this regard, I will appreciate it.

Thanks You Very Much.

Best Regards,

Fakhar

Yahoo! Shopping
Find Great Deals on Holiday Gifts at Yahoo! Shopping

Aleem @ Dubai

2005-12-07T11:18:00.000+05:00

As usual posting after a long time, the last few weeks have been quite busy and also so many things were changing that I could not get time to post.

I left Systems Private Limited, a gr8 place where I spent the last one year and it was great learning, they tried all they could to stop me, but I made the decesion to move on. It was an extremely tough decision and I have been under a lot of proessure. Anyway I was offered a job by KALSoft in Pakistan which included working for Vertscape in Dubai and I accpeted the offer. Its been a week now since I have joined the new company. Actually my office is at the client location at Dubai Airport Free Zone, West Wing Building 3.

Its a little challenging here with people from all cultures and its an experience getting adjusted. Also, the market is very competitive. The work is nearly the same, ASP.NET project with SQL Server and no documentation :).

Our Apartment is at a gr8 place, thats is the chorniche area at the start of Sharjah, and its a good place for walking and hanging out. I am spending most of the evenings just hanging here and there because I dont have a PC yet. I am thinking of getting a Notebook, there is a lot of brands to select from here and it is not very expensive also.

Anyway still getting accustomed to the project, thats the important thing.

Stored Procedure Encryption

2005-11-19T04:01:00.000+05:00

SQL Server stored procedures can be encrypted when they are shipped as part of a product. To Encrypt the SQL Server Stored Procedures so they cannot be read by anyone/client/developer/dbo, use the WITH ENCRYPTION with the procedure definition. Consider for example

CREATE PROCEDURE CustomerSample WITH ENCRYPTION

PRINT ‘This is an Encrypted Procedure’

I am looking forward to writing and Debugging Stored Procedures using the Visual Studio 2005.

.NET Serialization

2005-09-24T20:41:00.000+05:00

Serialization is used to persist the state of the object, so the object can be regenerated with the same state later. .NET provides different types of serializations for objects,

BinaryFormatter for bunary serialization
XMLSerializer class for XML Serialization
SoapFormatter class for Soap Serialization.

You can use these objects for serialization. The Framework also needs to serialize the objects at various places for example in case of web services, the objects needs to be serialized for communication, in case of Remoting and also if the object is to be passed across the boundary of an Application Domain or the process. In all these cases, the framework will only be able to successfully serialize your objects if your objects are serializable.

All the basic .NET types are serializable except Object, there are various other base classes which are by default serializable and can be successfully used in above scenarios, this includes the very commnly used DataSet, DataTable and other class, the complete list is

These classes are serializable because they implement the ISerializable Interface.

To set your own types Serializable, the most common way is to set the class/type with the [System.Serializable()] attribute, also use the [System.NonSerialized()] for the members that you don’t want to serialize. See the following example

[System.Serializable]

class TestClass

{

private string str = "Check";

[System.NonSerialized()]

private SqlCommand cmd = new SqlCommand();

private int count;

public CheckFunction()

{

........

}

However, using the serializable attribute is not the only way, and in some cases is not enough, specially if you are serializing complex objects which are inherited from other base objects. To serialize such objects you can have better control over serialization by implementing the ISerializable interface. This interface has only one method, which is GetObjectData(), this method is called when the object is to be serialized and you need to provide an extra constructor in the class to provide the de-serialization mechanism to regenerate the object. While serialization in GetObjectData() method, you can add your values to SerializationInfo parameter. During de-serialization you can get the values from the SerializationInfo object and set the values to the members of the class to regenarte the object in the same state. The example below will give you can idea

class TestClass : ISerializable

{

private string str = "Check";

private int count;

public TestClass(SerializationInfo info, StreamingContext context)

{

this.str = info.GetString("str");

this.count = info.GetInt32("count");

}

public void GetObjectData(SerializationInfo info, StreamingContext context)

{

// TODO: Add TestClass.GetObjectData implementation

info.AddValue("str",str);

info.AddValue("count",count);

}

Generally, as the MS guidelines and PAG documents say, serialization is not recommended for your custom objects, it has various issues regarding performance, security and scalability. But sometimes you have no other option then to use serialization. PAG guidelines do not recommend serialization and due to valid reasons but do not tell any other way you could get around the typical problems without serialization.

WinForm Stuff

2005-09-21T23:14:00.000+05:00

Just added the Jessica’s blog link to my outlook.

It has got a lots stuff on WinForms, could not get time to read as yet.

AJAX is Cool !

2005-09-21T22:59:00.000+05:00

Have you seen Orkut, Google Suggest, Google Maps. Are you amazed by the wonderful web experience? They are using AJAX. AJAX is a really good technique; I don’t call it a technology because it is nothing new, just a blend of few established technologies like JavaScript, XML etc.

To learn about the actual idea behind AJAX, you can go through the article http://www.adaptivepath.com/publications/essays/archives/000385.php.

There are many implementations and third party AJAX libraries available, the idea is not so difficult and you can even implement it yourself without using any library provided that you have time.

Anyway, for .NET programmers AJAX.NET is available, you can download the C# source form https://svn.borgworx.net/SVN/BorgWorX/trunk/Web/Core/Ajax/

Creating an application with AJAX.NET is not very difficult, just a few basic steps you need to follow, here is a good article at MSDN

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/ASPNetSpicedAjax.asp about using AJAX.NET.

Fiddler

2005-09-21T22:25:00.000+05:00

Fiddler is a really cool tool for HTTP Debugging. I have used it for some apps for testing and analyzing the requests from the app and the corresponding responses. You can get Fiddler Here: http://www.fiddlertool.com/fiddler/

WinFx Runtime Beta 1 and Whidbey

2005-09-20T23:30:00.000+05:00

Finally, after so much effort I have WinFX Runtime Beta1 installed on my system with Visual Studio.NET Beta 2. Could’nt get the WinFX SDK installed as yet so I don’t have the XAMLPAd. I downloaded the source for the Chris Anderson’s AvPad and it ran fine.

Wrote my first small Avalon application also; actually I just ran a sample to test everything is properly setup. I thought I’ll write some useful application by the end of the day today but could not get time. Its 11:15 PM now and I need to go home so maybe tomorrow I’ll try to write some Avalon code.

I am still figuring out the XAML and the procedural code relationship in Avalon, I never liked these split architectures. You have to write XAML and then the procedural code and somehow they work together. Also, I know you can Avalon App in pure procedural code without XAML.

I need to do some work on this and get comfortable with this new stuff, and by the way where WinForms stand now, you can still create a WinForm app, I still have to compare these two application types and what are the best places/scenarios for using each of them.

Anyway, VisualStudio.NET Beta 2 is amazing. The development experience is great, very comfortable and elegant. The new Error Window is really wonderful with that grid view.

I was thinking that Microsoft may be going too fast in some of its development; they should not update the products/specs so frequently. I downloaded C# 3.0 enhancements document today (haven’t seen it though). Now ppl haven’t used C# 2.0 as yet. Most people in my environment and other local software houses are using VS.NET 2003. C# 2.0 and Whidbey are still in the Beta and now they are proposing new C# 3.0.

Maybe this is because they have so many problems with these products that they tend to improve them continuously but this has a real bad effect on the programmer productivity. Most programmers are not able to get benefit and utilize the new features and changes. I think people at Microsoft and surrounding environment do benefit from everything that they add but medium/small companies are not using most of the new features.

I think they need to make a few solid releases without tweaking the things so often, if they need to get the Windows Vista and Widbey some real success at all levels.

Ok ! Its late .. I am leaving .. Bye!

Getting Printer Information thorugh WMI

2005-09-20T14:16:00.000+05:00

Hey,

I just got a mail from one of the friends, he wants to get the information about the printer like printer status, error, current status etc, I thought I should share the answer with all.

Yes there are ways to do this, the most common answer to almost anything related to any information in Windows is

WMI (Windows Management Instrumentation), this is the layer windows provides and uses for retrieving all sorts of information from the system and the running kernel.

In the following code I have listed all your printers on the system and also some of their properties/status like printing, stopped etc, but I can’t possibly list everything.

There is tons of information you can get about printer using WMI Win32_Printer class. Please refer to

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_printer.asp and modify this code according to what you actually need.

using System;

using System.Diagnostics;

using System.Management;

using System.ComponentModel;

namespace ConsoleWMI

{

class Class1

{

[STAThread]

static void Main(string[] args)

{

new Class1();

}

public Class1()

{

System.Management.ManagementObjectSearcher searcher = new ManagementObjectSearcher

("SELECT * FROM Win32_Printer");

foreach (ManagementObject service in searcher.Get())

{

string [] pStatus = {"Other","Unknown","Idle","Printing","WarmUp","Stopped Printing", "Offline"};

string [] pState = {"Paused","Error","Pending Deletion","Paper Jam","Paper Out","Manual Feed","Paper Problem",

"Offline","IO Active","Busy","Printing","Output Bin Full","Not Available","Waiting",

"Processing","Initialization","Warming Up","Toner Low","No Toner","Page Punt",

"User Intervention Required","Out of Memory","Door Open","Server_Unknown","Power Save"};

foreach(System.Management.PropertyData pData in service.Properties)

{

if(pData.Name == "Caption" || pData.Name == "Default" || pData.Name=="ServerName")

Console.WriteLine(pData.Name + " = " + pData.Value);

else if(pData.Name == "PrinterState")

Console.WriteLine(pData.Name + " = " + pState[Convert.ToInt32(pData.Value)]);

else if(pData.Name == "PrinterStatus")

Console.WriteLine(pData.Name + " = " + pStatus[Convert.ToInt32(pData.Value)]);

}

Console.WriteLine();

}

Console.ReadLine();

}

Network Load Balancing (Windows 2003 Server)

2005-09-16T02:28:00.000+05:00

These are the configurations of the cluster we set-up with two Windows 2003 Web Servers and a DB Server (see last post to catch up) . It is'nt a pure cluster actually but the Application Load Balancing, the load balancing service (available in Windows 2003 Server, I think its also in 2000 server but have'nt checked that) distributes the application requests among both the servers.

In contrast to this load balancing setup, a pure cluster also manages the server fail overs and the state of the servers, but it needs an extra bit of hardware, maybe i'll say something about that once we have that setup also.

This Load Balancing service in Windows 2003 Server is also interesting, I'll write a step-by-step process to setup NLB when next time I get to blog :) .. so stay tunned .... Also, there are a few other intersting things coming up, I think i'll be active here ...... C ya !

ASP.NET Session State Management

2005-09-16T02:11:00.000+05:00

This last week was great for learning. We had to setup our ASP.NET app on multiple web-servers/webcluster, the major issue in this case is that how session will be managed accross the cluster of webservers. ASP.NET Sessions can be managed in three ways, Ill just go briefly here and then you can go through the references if you need details

1- In-Proc Session Management: This is what we have in a default ASP.NET application. The ASP.NET worker process aspnet_wp.exe manages all processes.

2- Centralized Session State Server: The second way in which the ASP.NET sessions can be managed is through the Session State Server, which is the session management out of the process, in other words you can set the sessions to be managed on a separate machine and then all the web-servers can access the user session from there. (In my opinion this is the best way to go for a webfarm) .NET Framework comes with a Session State Service which u can run from the SCM. There is a <sessionstate> attribute in the application web.config file which needs to be set for the state server and you are ready to go.

3- Session Management with SQL-Server: The last method is the session management through the SQL-Server; you can manage the session in a SQL Server DB.

Although, the Framework provides the mechanisms but changing the way your application manages the state is not seamless and there are a lot of consideration which are to be taken during the application design if you want to make your application scalable for such an environment.

If you are implementing sessions through state server or through SQL-Server, in other words managing sessions out of the process, the objects placed in the sessions are serialized/de-serialized on each access. Now you need to insure that all the objects that you keep in sessions are Serializable otherwise the application will crash which trying to serialize a non-serializable object. Framework provides support for the native objects so they seem to serialize without any problem, apart from them there are a lot of other built-In library classes which implement the ISerializable interface which make them inherently serializable, this includes the DataSet and DataTable objects which are commonly used through the sessions. Still, there are other objects that you keep in sessions and you need to make them serializable.

Serialization/De-Serialization also introduces a performance overhead but in a cluster environment you have to bear that cost to enhance the application performance.

Setting the serialization is not very difficult; you can set the [Serializable] attribute over a class to make this class serializable provided that all its members are either serializable or native types. There are various issues involved with setting a type as serializable including the security and performance issues and generally setting serialization for your classes is not recommended but there seems no other solution if we need to manage the session out of process.

Maybe while designing the application you can avoid the use of your custom types through sessions so dont need to keep them in the session. You can also implement the ISerialiable and implement its GetObjectData() method to get a better control over serialization.

For furthur descussion about session states
http://www.msdn.microsoft.com/netframework/technologyinfo/infrastructure/tuning/default.aspx

For further discussion about the serialization issue http://msdn.microsoft.com/msdnmag/issues/05/09/SessionState/Default.aspx

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XML Schema Validator

2005-08-23T17:50:00.000+05:00

This is extremely trivial XML Schema Validator; I just needed to verify my XML against a Schema File. Very simple code but maybe helpful to someone.

using System;

using System.Xml;

using System.IO;

using System.Xml.Schema;

namespace XmlConsole

{

/// <summary>

/// Summary description for Class1.

/// </summary>

class Class1

{

private static int errors = 0;

/// <summary>

/// The main entry point for the application.

/// </summary>

[STAThread]

static void Main(string[] args)

{

try

{

// The Source XML File

XmlTextReader xtr = new XmlTextReader("C:\\devresult.xml");

XmlValidatingReader reader = new XmlValidatingReader(xtr);

reader.ValidationType = ValidationType.Schema;

// The Path of the XML Schema File against which the Validation is to be made.

// you can add more than one Files by using reader.Schemas.Add()

reader.Schemas.Add(null,new XmlTextReader(@"E:\Schema.xsd"));

reader.ValidationEventHandler += new ValidationEventHandler(reader_ValidationEventHandler);

while(reader.Read());

xtr.Close();

reader.Close();

if(errors == 0)

System.Console.WriteLine("Validation Successfull");

else

System.Console.WriteLine("Validation Failed");

System.Console.ReadLine();

}

catch(Exception exp)

{

System.Console.WriteLine(exp.Message);

errors ++;

}

private static void reader_ValidationEventHandler(object sender, ValidationEventArgs e)

{

System.Console.WriteLine(e.Message);

}

Parameter Passing Quiz :)

2005-08-18T15:07:00.000+05:00

Ok, again posting after a long time.

Predict the output of the following code, the contains 3 sets of function calls, each set contains one call by value and one by reference, but the object being passed everytime is a reference type. It is recommended that you do not run the code, just predict the output.

StringBuilder used in the code is a class and is a reference type.

Also explain your answers.

class Class1

{

static void Main(string[] args)

{

StringBuilder str;

// Set 1