All About Information Technology

What is in a page

2009-04-13T09:56:00.001-05:00

Page Object contains a reference to:
• Request object
• Response object

• Application object
• Session object

• Trace object
• Server object
• User Object
• PreviousPage object

ASP.NET Event Load Sequences

2009-04-13T09:53:00.002-05:00

Pre-init event
• Ispostback is available but not control view states
• Set Global properties
o Dynamic master page
o Profile properties
o Applied skin/theme settings
• Recreate dynamically created controls

Init Event
• Fires after elements been initialized and skin setting has been applied
• Read or write any specific control properties

Init Complete
• After all initialization been complete
• Implement logic that depends on controls be initialized

Preload
• Process control before they are loaded
• A pre-load for each control
• After this viewstate gets initializes and postback information gets initialized

Load event
• Page load then each control’s load and then any specific control events (change,click etc)

Load complete
• Control all loaded, viewstates been loaded and validated has occured

Prerender
• All databind been called
• All child prerender been called

Save View State
• All values has been created and saved
• Can’t implement logic that we want to appeared they will be ignored
• Can implement logic that used the viewstate

Retriving application path

2009-04-09T13:43:00.002-05:00

Virtual path or web path

dim webPath as string = HttpContext.Current.Request.ApplicationPath

works the same as "~"

Physical is the actual path
dim physicalPath as string = HttpContext.Current.Request.MapPath(appPath)

Gridview.Databind - Once per load

2009-03-05T10:22:00.002-05:00

* Remove extra databinds for grideviews - You should only have one per page load.

I was getting "Item has already been added" error in a page containing multiple multiviews/views/gridviews. This makes it very easy to mistakenly add an extra databind somewhere.

This problem is also exasperated by the usage of different select sqls populating the gridviews.

Inaddition for some reason the extra databind does not cause a problem in my local machine or my company server. It only started acting up when I uploaded to a ISP.

IE8

2009-02-26T15:22:00.002-05:00

I upgraded to IE8 recently and it seem to be much smarter. However it does not display my websites the same way.

From what I have seeem it tends to disply more along the line of firefox as oppose to IE7

Some browser differences for validation controls

2009-02-26T15:16:00.002-05:00

For IE when i disable a control it takes the validation control out of play, but when I run the same file in songbird it does not work. It is not visible but it interferes with the submitting of the form.

When I set the visible property of the validation control to disable then it works.

How to Fing Control in EmptyData Row in Gridview for VB.NET

2009-02-17T12:23:00.003-05:00

It's simple but not very intuiative.

VB.NET
gvDisplay.Controls(0).Controls(0).Controls(0).FindControl("controlid")

VB.NET turn links cursor into text cursor

2009-02-13T09:34:00.002-05:00

Sometimes vb.net application will turn the curesor for links (pointer) into text cursor (I).

I find that if you specifically specify the a tag to a pointer then it will fix that problem.

a
{
cursor:pointer;
}

.NET Request object properties

2009-02-13T08:52:00.004-05:00

Request Property Function and Example

ApplicationPath -Returns the a Web server relative path to your application root /WestwindWebStore/

PhysicalApplicationPath -
Returns a local file system path to your application root D:\inetpub\wwwroot\WestWindWebStore\

PhysicalPath - Returns the full file system path to the currently executing script D:\inetpub\wwwroot\WestWindWebStore\Item.aspx

CurrentExecutionFilePath - FilePath

Path - In most situations all of these return the virtual path to the currently executing script relative to the Web Server root. /WestwindWebStore/item.aspx

PathInfo - Returns any extra path following the script name. Rarely used – this value is usually blank. /WestwindWebStore/item.aspx/ExtraPathInfo

RawUrl - Returns the application relative URL including querystring or pathinfo
/WestwindWebStore/item.aspx?sku=WWHELP30

Url - Returns the fully qualified URL including domain and protocol
http://www.west-wind.com/Webstore/item.aspx?sku=WWHELP30

Page.TemplateSourceDirectory - Control.TemplateSourceDirectory
Returns the virtual path of the currently executing control (or page). Very useful if you need to know the location of your ASCX control instead of the location of the page. /WestwindWebStore/admin

Above copied from http://www.west-wind.com/weblog/posts/269.aspx

Link to the application root
use Request.ApplicationPath

Set Focus to textbox after updatepanel updates

2009-02-12T13:03:00.008-05:00

VB.NET

I have a gridview in a update panel displaying a set of records. When I select a record I want to set focus to a text box. This following script will do that

Set the following cod under the script manager or you will get the sys object not found error


<script type="text/javascript" language="javascript">
    Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
    function EndRequestHandler(sender, args) {
        //Use timer so that the script will wait .5 sec before it fires to let page complete rendering the txtDSChartNumber element
       setTimeout ( 'setFocus(\'txtDSChartNumber\')', 500 );
     }
     function setFocus(controlid) {
        if (document.getElementById(controlid)){
            document.getElementById(controlid).focus();
            document.getElementById(controlid).select();
         }
     }
</script>

Call server function without post back using ICallbackEventHandler

2009-02-11T13:20:00.005-05:00

Steps

Implements the ICallbackEventHandler in the partial class of the code behind file.

Create a client script in the aspx page to be called from server so result can be returned

Use the ClientScriptmanager to get a reference to the client script you created

ClientScriptmanager. RegisterClientScriptBlock fucntion
- a. to register the callback script that is used by the client elements to call the server
- b. to register the script reference we got for step3
Create the RaiseCallbackEvent sub that is used to retrive client arguemnts

Retriving Identity Value after Insert

2009-02-05T12:17:00.004-05:00

Database: Microsoft SQL Server
Program IDE: VB.NET 2005

I want to retrive the auto generated identity value after I insert a record into an identity column.

There were a lot of stuff about it but nothing that work work without using a stored procedure.

Basically I enclosed the insert and select into a transaction

The following is what I did
________________________________________________________________



        ' Add the input parameter and set its properties.
        Dim parameter As New Data.SqlClient.SqlParameter("pk", Data.SqlDbType.BigInt)
        parameter.Direction = Data.ParameterDirection.Output
        cmd.Parameters.Add(parameter)

        'set insertSql to somthing u do
        cmd.CommandText = "begin transaction" & vbCrLf & insertSql & vbCrLf & "select @pk =cast(scope_identity() as int);" & vbCrLf & "commit transaction"
        'added try block 7/10/08
        Try

            Dim msg = cmd.ExecuteNonQuery()
            If Val(msg) = 1 Then
                'parameter.Value returns the insert identity
                msg = parameter.Value
            End If
        Catch
            'output error
        End Try

_____________________________________________________________________________

IE6's Selective Cookieing

2006-05-31T18:26:00.000-05:00

One of my student had a question about cookies and sessions. He stated that ASP sessions are handled by cookies. It had been a while since I use ASP, but I was sure that sessions were handled by objects created on the server side.

So we proceed to a heated discussion of session and its relationship with cookies. We found that ASP does use server side session objects, but it also requires cookies to be enabled on the browser client side by default.

During this discussion(taken place over many months), I finally did something. I demonstrated that you can actually set IE6 to block all cookies and still use the ASP Session object. I thought this really proved my point (That he was wrong and I was right - This was my downfall).

One week after I demonstrated the ability of IE6 to use sessions with all cookies blocked, this student comes in to class and mentioned something about transient cookies -- a type of cookie that was stored in memory instead of the hard drive.

Well that still does not make it a cookie, because a cookie must be a file that is stored on the client side. He then proceed to download and use Cookie Spy to show me that there was a cookie written to IE6 even after setting it to block all cookies. I told him to try Firefox and he did. The result is that in Firefox, not allowing cookies, also disables ASP sessions.

WOW this really suprisingly unsuprising. We have uncovered a hidden feature implemented by Microsoft to purposefully underminds a functional feature of IE6 that blocks all cookies. The result:

Microsoft Session Objects was able to write a cookie to the client computer using IE6 even after setting IE6 to block all cookies.

When to use MySQL persistent connections.

2006-05-20T16:27:00.000-05:00

In PHP a persistent connection is a constant connection to the database. It will not be deleted or closed after a php script exits. This provides a reduction in connection time bypassing the time needed to create a new connection. In timed tests, the persistent connection is obviously much faster than the regular connection after the persistent connection is made. With this in mind, we probable want to switch all of our MySQL connections to persistent just about now right?

According to php.net, a persistent connection does not mean one connection for one database resource. It actually means one connection for each child instant of Apache (I check the MS IIS6.0 server and I think that it also mean a persistent connection for each IIS worker process.). So if a web server has 255 instances and it hosts 100 applications that require persistent connections, then the MySQL server would eventually need to serve 255,000 connections. As you can see, this is a very large number.

Tim the CTO of Digital Content Solutions has posed a solution for a high volume high traffic website setup (http://www-css.fnal.gov/dsg/external/freeware/mysqlTuning.html). This would be a good example of where persistent connection would be good. Tim mentioned that there were up to 3000 users that log in about 5-7 hours a day. Since the max client for apache is 255, only a maximum of 255 persistent connections is ever needed from mySQL.

Time Test

Brinkster Server

System Windows NT ORF-SINGLE6 5.2 build 3790/ Microsoft-IIS/6.0

PHP Version 4.3.6 with mysql.allow_persistent = off.

MySQL 4.1.8-nt running

All time results are measured in microseconds. 1 us = 0.0000001 second.

The result for opening mysql connection 100 times in one page. Brinkster server

Mysql_connect

Mysql_pconnect

100 Loops

0.352324008942

Average
0.00352324008942

9.40135145187

Average
0.0940135145187

The result for opening mysql connection 100 times in one page accessing a table containing 4 records. Brinkster server

Mysql_connect

Mysql_pconnect

100 Loops

18.3291544914

Average
0.183291544914

26.7511310577

Average
0.267511310577

The times from one connection of 10 tests while reading 4 records from a table using brinkster’s mysql server..

	brinkster mysql server.
	Mysql_connect	Mysql_pconnect
1.	0.529908895493	0.621995567452
2.	0.531473875046	0.265028953552
3.	0.537230014801	0.26303601265
4.	0.530024051666	0.268359899521
5.	0.527902126312	0.268362045288
6.	0.541395902634	0.264112949371
7.	0.538422107697	0.270877838135
8.	0.53887295723	0.26437997818
9.	0.530326128006	0.26514005661
10.	0.530980825424	0.268352985382
Average	0.533653688	0.301964629

The times from one connection of 10 tests.

	Brinkster’s mysql server.
	Mysql_connect	Mysql_pconnect
1.	0.351463079453	0.511427879333
2.	0.349606990814	0.0880341529846
3.	0.350552082062	0.0887169837952
4.	0.350438117981	0.086434841156
5.	0.350795984268	0.0876920223236
6.	0.349910974503	0.0873341560364
7.	0.35268497467	0.0879299640656
8.	0.352124929428	0.087671995163
9.	0.351628065109	0.0874209403992
10.	0.349985122681	0.0872449874878
Average	0.350919032	0.129990792

Local Server

Apache Version Apache/2.0.55 (Win32) PHP/5.1.2

System Windows NT LIXP1 5.1 build 2600

MySQL - 5.0.19-nt

The result for opening mysql connection 100 times in one page. My local server
	Mysql_connect	Mysql_pconnect
100 Loops	0.00388431549072 Average 3.88431549072E-005	0.0451853275299 Average 0.000451853275299
50 Loops	0. 00345373153687 Average 6.90746307373E-005	1. 0278699398041 Average 0.000557398796082

The times from one connection of 10 tests

	My local mysql server.
	Mysql_connect	Mysql_pconnect
1.	0.00294303894043	0.040155172348
2.	0.00240993499756	0.000385999679565
3.	0.00236296653748	0.000363111495972
4.	0.00245308876038	0.0017511844635
5.	0.00341415405273	0.000352144241333
6.	0.00240993499756	0.000328063964844
7.	0.00242400169373	0.000353097915649
8.	0.00235104560852	0.000352144241333
9.	0.00242209434509	0.000353097915649
10.	0.00242209434509	0.000355005264282
Average	0.002561235	0.004474902

The result for opening mysql connection 100 times in one page while reading a table of 4 records. My local server

Mysql_connect

Mysql_pconnect

Time used mysql_connect for 100 loops:
0.17444396019

Average Time used for 100 loops:
0.0017444396019

Time used mysql_pconnect for 100 loops:
0.221433877945

Average Time used for 100 loops:
0.00221433877945

The result for opening mysql connection 50 times in one page while reading a table of 4 records. My local server

Mysql_connect

Mysql_pconnect

Time used mysql_connect for 50 loops:
0.0991790294647

Average Time used for 50 loops:
0.00198358058929

Time used mysql_pconnect for 50 loops:
0.116796016693

Average Time used for 50 loops:
0.00233592033386

The times from one connection of 10 tests while reading 4 records from a table.

	My local mysql server.
	Mysql_connect	Mysql_pconnect
11.	0.00404787063599	0.0169429779053
12.	0.00396800041199	0.00390601158142
13.	0.00410914421082	0.00385713577271
14.	0.00394082069397	0.00535202026367
15.	0.00400495529175	0.0048680305481
16.	0.00412011146545	0.00550007820129
17.	0.00731420516968	0.00530409812927
18.	0.0049569606781	0.00393199920654
19.	0.00558114051819	0.00378203392029
20.	0.0039439201355	0.00528407096863
Average	0.004598713	0.005872846

The times from one connection of 10 tests while reading 4 records from a table with mysql.allow_persistent = off.

	My local mysql server.
	Mysql_connect	Mysql_pconnect
1.	0.0159568786621	0.0151901245117
2.	0.00385808944702	0.0039529800415
3.	0.00757598876953	0.00386190414429
4.	0.00387406349182	0.00486707687378
5.	0.00535702705383	0.00385594367981
6.	0.00966596603394	0.00410199165344
7.	0.00771403312683	0.00383496284485
8.	0.00882005691528	0.00390315055847
9.	0.00531911849976	0.0038628578186
10.	0.00528693199158	0.00381398200989
Average	0.007342815	0.005124497

The following observations are made from the data collected.

(1) Multiple instance of calling the same persistent connections takes additional time while regular connections do not.

(2) The persistent connection requires significantly higher resources when it is called for the 1^st time.

(3) Persistent connection uses up a lot of server resources.

(4) Persistent connection gives better performance when the MySQL server is located at a remote location.

(5) Do not use the mysql_pconnect() more than once in each page, because the MySQL actually takes time to do something if you do use it more than once. I do not observer this performance decrease in mysql_connect().

(6) The persistent connection directive appears to have minimal effect on the speed of access.

Note: There don’t seem to be a lot of problems associated with the persistent connection for MySQL. But many hits result for using PostgreSQL and ODBC.

Defining Information Technology

2006-05-11T09:19:00.000-05:00

What is information technology (IT)?

This seems to be a very easy answer. If you look it up on Google (google it), then you might find the following (depending on current ranking and web URL linkage): IT is about computers. IT uses information. IT delivers information.

My view of IT has always been different than the majority of the world. To me IT is not all about computers. It is not all about repair/support/provide computing services.

If IT is not about providing computer related services, what is it about?

Well, we need to first examine to see if we are talking about the same IT. The IT I am talking about is the discipline of IT. It is not about a specific information technology or a group of information technologies. I am referring to IT not a group of technologies that are related to information, but as a field of study that create and improves on the way data can be transform into something more valuable. Other common disciplines are Astrophysics, Applied Mathematics and Computer Science.

IT as a field of study

If you view IT as a field of study, as a discipline then we are looking at the same IT. This IT to me is a systematic study of all things concerning information technologies with the goal of advancing knowledge in this discipline. This is a circular definition, because I define IT using similar terms. Although Information Technology is not the same as an information technology, they are similar enough that people confuse the two.

To clarify, IT is a field of study, while information technology is just a procedure that process data. Computer Science is a field of study, while the act of coding is a sequence of actions that produces software applications.

Lets us examine a specific information technology: word processing. The technique of word processing describes a method to add, modify and delete text. Implementing this technique, we code a piece of software that enables us to add, modify and delete words for example, Text EditorA. Notice that the result of applying the information technology is the Text EditorA. The technology itself is not the Text EditorA.

Although IT hardware and software are the indispensable tools of an information technologist, they are still tools. The current popular definitions of IT relegate IT professionals to be creator and caretaker of IT tools and not the provider of value adding services. IT is almost an after thought, only comes into focus when it fails. By segregating the IT practitioner from the value adding activities, many organization are doom to failure because of reliance on products designed by a none IT individual who can't fully utilize the power of current information technologies and produced by an IT professional who don't understand the value adding activities.

IT is more then support; it adds values

Since current paradigms have misplaced the importance of IT, why are many companies still successful? The answer is very simple, successful companies give its employees the ability to perform value-adding activities. Lots of those activities will involve implementation of information technologies. These implementations are important to the well being of a company, which make the people servicing them to gain importance. However, the important part is still the application logic.

Why is Wal-Mart so successful? K-Mart was bigger and had more locations. How did Wal-Mart raised up and dominate the retail market? The difference is not in the computer related technologies. The competitive edge is based in the true IT. The value adding activities performed on data are the reason that Wal-Mart was so successful. Part of it was due to computer related technologies, but K-Mart had access to those too. K-Mart just did not choose to implement the value adding activities.

Google was able to dominate the search engine market partially due to the implementation of the distributed database on low cost PCs, but it was the concept of ranking the importance that pages that draw the people to it. Sure Google cuts cost using the low cost PC, but its ability to return relevant hits was the real reason that Google was so successful.

Problem with the way things are

So what does this have to do with the definition of IT? If industries continue to segregate IT professional from value adding activities, then a lot of waste and inefficiency will be the result. If we direct IT curriculums toward more hardware/software based and treat IT as a program that are used to support information technologies, we are focusing our energy at the wrong juncture. Doing this is like training a lot of mechanics to repair cars instead of investing in improving the vehicle design.

Industries needs to integrate IT by training the people in charge with the current IT, not trying to hiring someone else to do the design. The actual IT activities must be done in house. These activities are the bases of a company. They form the competitive edge of a company, if you leave them to others, then you are placing yourself at their mercy.

Companies may think that they have successfully outsourced their IT. However, the only part that they can really outsource effectively is the computer related services and support. The real value-adding portion cannot be outsourced. This part has to stay within the company, because it is the way company operates. It is the part that cannot be learned without on-site participation. When situation changes, the outsourced IT will become inefficient and needs to adopt. However this adaptation will occur must slower than companies that has the IT in house. If this change in efficiency is not monitored and detected then the company may lose more than it gains by the outsourcing. This is a classic example of over optimization of a sub module (The cost saving of outsourcing IT) causing the entire system to achieve lower efficiency. Often times we see large companies cutting IT staff to save money, because the value adding services of IT is not readily measurable. After a while the IT system and infrastructures become unmanageable, because the low staffing level and constant call for service put the IT department in a firefighting mode. Once this has occur, it becomes very hard to identify problems and impossible to improve value adding services.

Definitions: (5/12/2006 - whatcanbe)
Information Technology (IT) is the discipline that systematically studies methods and processes that increase the value of data and structured data by processing, generating, and/or delivering the result to the right person in the right place at the right time.

References
techweb.com: http://www.techweb.com/encyclopedia/defineterm.jhtml?term=IT
IT (Information Technology) Processing information by computer. IT is an umbrella term for the entire computer industry and its latest moniker, which took hold in the 1990s. It actually took 40 years before the industry settled on what to call itself. First it was "electronic data processing" (EDP), which was followed by "management information systems" (MIS) and then "information systems" (IS).

webopedia.com: http://www.webopedia.com/TERM/I/IT.html
IT - Short for Information Technology, and pronounced as separate letters, the broad subject concerned with all aspects of managing and processing information, especially within a large organization or company. Because computers are central to information management, computer departments within companies and universities are often called IT departments. Some companies refer to this department as IS (Information Services) or MIS (Management Information Services).

whatis.com: search390.com Definitions - IT
IT (information technology) is a term that encompasses all forms of technology used to create, store, exchange, and use information in its various forms (business data, voice conversations, still images, motion pictures, multimedia presentations, and other forms, including those not yet conceived). It's a convenient term for including both telephony and computer technology in the same word. It is the technology that is driving what has often been called "the information revolution."

rice.edu: http://www.rice.edu/it/vpit/mission.html
IT Tasks

Work with the Rice University community to identify and deliver quality service and solutions that meet the information needs of the University.
Provide leadership and planning for the effective and informed use of technology and the thoughtful exploration of new technologies.
Create, communicate, and implement rational funding models for information technology initiatives and services.
Promote the professional development of IT staff.
Constantly strive to exceed customer expectations through our professionalism, courtesy, consistency, and commitment to excellence.

nd.gov: http://www.nd.gov/itd/planning/definition.html
Information Technology means the use of hardware, software, services, and supporting infrastructure to manage and deliver information using voice, data, and video.