Category: Blog Posts

The InvokeWorkflow activity which comes with
Workflow Foundation (.NET 3.0) executes a workflow
asynchronously. So, if you are calling a workflow from ASP.NET
which in turn calls another workflow, the second workflow is going
to be terminated prematurely instead of executing completely. The
reason is, ManualWorkflowSchedulerService will execute
the first workflow synchronously and then finish the workflow
execution and close down. If you used InvokeWorkflow
activity in order to run another workflow from the first workflow,
it will start on another thread and it will not get enough time to
execute completely before the parent workflow ends.

Here you see only one activity in the second workflow gets the
chance to execute. The remaining two activities do not get called
at all.

Luckily I found an implementation of synchronous workflow
execution at:

http://www.masteringbiztalk.com/blogs/jon/PermaLink,guid,7be9fb53-0ddf-4633-b358-01c3e9999088.aspx

It’s an activity which takes the workflow as input and executes
it synchronously. The implementation is very interesting to see.
Please see the original blog post for details.

This is one of those moments in history which you must be really
lucky to witness. Can you believe MSDN actually had a connection
string problem in their website which were exposed wide open to the
public? Also they deployed the site in debug mode in order to see
the error. Moreover, they actually turned on showing remote errors.
Must have been really hard to find what was wrong with the
site.

So, what we learn from here?

• Don’t deploy production site in debug mode
• Do not set “off” to . Anyone can see stack
  trace of your web application. Hackers can collect valuable
  information from these stack traces
• Put enough logging in your code so that you can analyze server
  side log in order to find out what’s wrong with your web app. Don’t
  just turn off custom errors in order to see why the site is not
  working.
• Put a good custom error page which apologizes to users and
  gives them enough links to either contact support or go to some
  other pages.
• Produce error alerts via email, SMS or IM Client when your site
  experiences such problems. This is the best way to learn about
  fatal errors on site and take action quickly.

When you have a pretty large web site in Visual Studio 2005, the
site build time grows dramatically and it becomes very difficult to
change code and then hit F5 (or Ctrl+Shift+B) in order to see if
the project builds properly or not. In Pageflakes, we have a giant web
site. It takes so long to build the site that we generally issue
the build command, go to kitchen and make a cup of tea, drink it,
come back and see the site still building. Generally when we do
this 20 to 30 times per day, we start feeling sick (not
because of VS 2005 instead of too much tea).

Here’s a cool idea we tried. You can make
folders hidden by going to Windows Explorer, go to Folder
properties, check mark “Hidden” and click OK and then select “Apply
to current item only”. This will make the folder hidden and the
folder will disappear from Windows Explorer unless you have turned
on the option to show hidden files and folders. You will also see
the folders disappeared from Visual Studio. Now we use Total
Commander instead of Windows Explorer so hidden folders are not a
problem to us. Bascially none of us remember anymore how to use
Windows Explorer because we are so used to Total Commander now. Try it, it will
change your life.

When you make folders hidden, Visual Studio will not build them!
So you can make App_Data, App_Themes, images, stylesheets,
javascripts, html files hidden and Visual Studio will skip them.
Around 70% of our web site is non C# code. So, we gained dramatical
reduction in web site build time by trying this idea. Another idea
is to move all classes from App_Code to external DLL project. Thus
they will build once and VS will not build them again and again if
you make some changes in some codebehind file or some .aspx or
.ascx file. This will also give you significant build time
reduction.

Of course you can turn off Build Website and use Build Page
option. But that does not help. We want to ensure the web site code
is not broken due to any change. So, we need Build Website
option.

I have published a new article in codeproject:

ASP.net Ajax under the hood secrets

You will find the following tricks on it:

• Batch call advantages and disadvantages
• Implement auto retry in all web method call by modifying Ajax
  core framework
• Implement queue based web method call in order to prevent
  browser from getting stuck with too many Ajax calls
• Caching web method response, fix bug in ASP.net 2.0 cache
  header problem
• How slow is Http Post, capture data transfer over the wire and
  see

Some of the techniques may be known to you if you have read my
earlier posts. But I have converted all code to the latest ASP.net
Ajax Beta 2 version which is not available in the blog posts.

Please rate the article if you like it at codeproject.

Also please digg
this article.

I get a lot of request from a lot of people who see my works and
get inspired and ask me how can they do the same? The questions I
generally get are following:

• How can I develop projects like you did?
• What do I need to learn in C# to become like you?
• Does Microsoft Certifications help? Should I go for the
  exams?
• What did you do to become MVP? I want to become MVP too.
• I am 23 (or 24), fresh graduate and I want to become like you. What do I need
  to do?

Generally the questions are like this. Everyone asks me for a
“shortcut” way to becoming a really good developer. So, here’s the
magical secret for becoming a really good developer and achieve
everything I have achieved:

Work 16 hours per day, 7 days a week, 360 days a year for
13 years.

Yes! That’s the secret. It’s pretty easy. The only thing you
need to do is “work” and do nothing else and you will achieve
everything that I have achieved. Pretty easy. I did that, so you
can do it too! Piece of cake.

If you want to go for the “long” way then here’re the things you
can try:

• Take part in open source projects or make several yourselve.
  This is the best way to learn really useful things.
• If you can, try setting up your own company. I have setup 3
  companies so far. 2 were not that succesful, 1 is very
  successful. It helped me learn so many things that I would have
  never learnt by working in other’s companies as an employee. The best lessons are learnt from the failures. I learnt a long list of “What not to do in a software development project”, which came very handy when I did my later projects. The more I failed in my earlier projects, the less mistakes I made in my later projects. The key is not to give up even if you fail to deliver 10 projects successfully in a row. Keep an open eye, do a retrospective and find out what made it fail, and especially what *you* did wrong.
• Read articles everyday. There are thousands of articles to read
  from www.codeproject.com and
  msdn.microsoft.com. I use my Pageflakes page www.pageflakes.com/omar to keep in touch with the technology world everyday. I still read almost all the articles that get
  published in codeproject every week. If you read 10 articles per
  week and do it for a year weeks, you have the knowledge
  of 480 articles! Who can beat you then?
• Not only read articles, but try out the attached source codes.
  Make similar projects yourselves and use the ideas presented in the
  articles in your own project. I spend everyday at least 1 hour in
  trying out new technologies. This not only increases my knowledge
  but also makes me more experienced in doing things better and helps
  me do my office work better and faster.
• Get into companies which gives you exciting projects to work on
  and you get to do something in everything. For example, join a
  company which gives you the freedom to design your modules, develop
  it, test it, document it etc. The idea is to gain experience from
  all stages of development. Make sure the company has enough bright
  stars to learn from. If you just become another cow in a big dairy
  farm, no benefit.
• Don’t leave a company if you are underpaid but you do a lot for
  the company. Have patience. Build yourself up and you will one day
  get what you deserve. I used to get $250/mo in my first
  company, which used to do outsourced projects for a really big
  company in US. I worked day and night in that company and worked in
  8 projects in 7 years. I did not leave the company because of
  the technologies I could learn and apply and the variety of things
  I could do there besides just coding. Best of all, I could work on many outsourced
  projects myself from various countries which exposed me to a wide
  variety of technologies, culture, and business. So, when I left the company and
  joined another one, with the vast experience I had gathered from my
  previous underpaid company, my salary became $200/day in the new
  company. See the difference. If I had left earlier seeking higher
  salary instead of technologies, I would not have learned all the
  cool things and I would not become so expensive as I am
  now.
• This is very important for those who cost $200/day now. Don’t
  change yourself once you start earning this much. Be the same
  person as you were when you used to get $200/month. Remember, it
  was the attitude and the burning desire to learn and grow that
  made you become what you are now. If the burning sun inside you
  becomes a dying candle, you lose.
• Don’t start your career in a company where you are given nice
  specs to read on, you have lead developers to decide all
  input/output/pseudocodes, you have a solid QA team to test
  your work, you have managers and administrators to take care of
  every management and administrative issues etc. In such a company,
  the only thing you become is a “smart typist”. You basically
  translate English to C#. The right side of your brain does not
  develop at all. Start your career with small companies which deal
  with lots of challenges and you get the chance to burn your brain
  and fingers out. The sweet smell of your roasted brain is far
  better than the sweet scent of your polished cubicle inside a
  decorated corporate office.
• I have seen the following evolutionary cycle of developers and
  see where you fit in:
• • Beginner: Does not wear shoes, comes to office on sandles.
    Looks very sober. Shirt is outside pant. When you ask them,
    do you know .NET events and delegates? They say, “uh, ummm, no I
    don’t think so. Is it birthday events?”
  • Beginner+: Gives you “I know it all” look whenever you talk
    about programming. Wears shiny shoes, full sleve shirt is
    nicely put inside dockers pants. Back brushed hair wtih
    “Set Wet” gel and always on 300 sunglasses. When you ask them, “do
    you know .NET events and delegates?” They say, “Events and
    delegates are coooool man! You can do anything with them and mark
    my word man, “anything”. I haved used them in sooooo many
    projects. Did you just learn about .NET events and
    delegates?”
  • Intermediate: Clothing turns a bit pale. Sunglass is
    old-school. No hair gel. Anytime you speak about some terms like
    EJB, Spring, Design Patterns, their eyes sparkle like the brightest
    star in the November sky. They start doing a lot of off-the-record
    work inside office. They start going to online groups, start
    working with friends on open source projects, start reading MSDN
    Magazines etc. If you ask them, “Can you make it?” They always
    reply, “Sure, you will get it tomorrow.” But usually you get it
    after a month.
  • Intermediate+: Generally you get it within 1 or 2 weeks overdue
    schedule.
  • Advanced: They wear the same “I am a Geek”
    or “Microsoft Windows XP” logo T-shirts everyday (until it
    stinks and you can smell it as soon as they enter the
    office) and shiny sports shoes. They start talking about
    software development processes, RUP, Extreme Programming,
    Agile Development etc. If you ask them to do something, they
    reply “Give me a functional specification, a technical
    specification, test plans, milestones, release plans, mockups and N
    number of developers and I will get it done.”
  • Very advanced: Does not wear shoes, comes to office on sandles.
    Looks very sober. Shirt is outside pant. When you ask them,
    do you know .NET events and delegates? They say, “They seem to
    suffer from bi-directional strong reference problem which
    prevents garbage collectors from collecting the listener properly
    and the only way to release the reference is to bring down the app
    domain”
• Do take Microsoft Certifications without cheating. You will
  learn a lot.
• Write articles & blogs. Share everything you learn. Someone
  out there will benefit from it someday. Don’t hesitate thinking
  that you don’t know much to write about.

I have been awarded MVP Award 2007 on Visual C# again. This is
my second year. This time the gifts are realy nice. This program is
getting better and better every year. The level of support and
appreciation MVPs receive from Microsoft by this award is
phenomenal. Free MSDN Universal Susbcription, Visual Studio Team
System, TechEd 2006 DVDs, woohoo!

You might be thinking, you did nothing for the community! How
come you get this award?

Here’s what I did:

Ajax Series

• 
  Beginning Atlas series: Why Atlas?
• 
  Atlas 1: Try not to use page methods
• 
  Atlas 2: HTTP POST is slower and it’s default in Atlas
• 
  Atlas 3: Atlas batch calls are not always faster
• 
  Atlas 4: Only 2 calls at a time and don’t expect any order
• 
  Atlas 5: Bad calls make good calls timeout
• 
  Atlas 6: When ‘this’ is not really ‘this’
• 
  Atlas 7: Caching web service response on browser and save bandwidth
  significantly

ASP.NET 2.0 Series

• IIS 6
  Compression – quickest and effective way to do it for ASP.NET
  compression
• Client
  side Page Fragment Output cache, reduce page download time
  significantly
• Web
  Application performance optimization tips
• Optimize
  ASP.NET 2.0 Profile Provider before you go live
• How
  to use ASP.NET 2.0 Profile object from web service code
• How
  to change user name in ASP.NET 2.0 Membership Provider
• Forms
  authentication failed for the request. Reason: The ticket supplied
  was invalid. (Solution)
• Redirect
  Traffic from old to new server when you change hosting
  service
• Things
  you must do for ASP.NET 2.0 Membership Provider before going
  live
• 
  Careful when querying on aspnet_users, aspnet_membership and
  aspnet_profile tables used by ASP.NET 2.0 Membership and Profile
  provider

You say, “Huh, big deal, I can write such simple artlcles
everyday”. Then read this:

StickOut – .NET 2.0, VSTS, Outlook Addin, MS Word/Excel
integration

When I was in univerisity, from day 1 at my first semester, I
looked for oppotunities not to attend classes or do homeworks
instead go and work at my office more. Attending classes, taking
class tests, collecting lecture notes, paying dues in long queues,
doing course registration all seemed like a waste of my valuable
time. I could do so many things if I were not doing those things.
So, I was thinking about automating all these so that I can do them
over the web from my office or home and thus save going to
university. This resulted in a state-of-the-art web based, smart
client powered univerisity automation and collaboration system
which now runs at my univeristy web site www.aiub.edu.

It created a lot of buzz in the country because it was the first
ever complete implementation of such a system not only in
Bangladesh but also in many other countries. You will hardly find
such feature rich automated system in Universites in US, Europe or
Australia. We got so many proposals from famous universities in US
who wanted to buy this project. This project was also
praised in many daily newspapers. There’s a recent review published
in a daily which suddenly brought back old memories and made it to
this post:

http://www.thedailystar.net/campus/2006/09/04/acad…

It was also the first ever .NET project completed in my
country.

Here’s what a student sees when logged in:

Here’s details of a course:

Atlas by default makes HTTP POST for all AJAX calls. Http POST
is more expensive than Http GET. It transmits more bytes over the
wire, thus taking precious network time and it also makes ASP.NET
do extra processing on the server end. So, you should use Http Get
as much as possible. However, Http Get does not allow you to pass
objects as parameters. You can pass numeric, string and date only.
When you make a Http Get call, Atlas builds an encoded url and
makes a hit to that url. So, you must not pass too much content
which makes the url become larger than 2048 chars. As far as I
know, that’s what is the max length of any url.

Another evil thing about http post is, it’s actually 2 calls.
First browser sends the http post headers and server replies with
“HTTP 100 Continue”. When browser receives this, it sends the
actual body. Here’s what the headers look like:

Request:

After getting this clearance from the server, the actual body is
sent. This is done in order to prevent long posts which are not
going to succeed anyway if the server cannot accept it. But it
comes at the cost of network latency.

So, Http Get should be at least twice faster than Http Post.

Here’s how you make Http GET calls in Atlas:

Step 1: Decorate web method with attribute

First you need to put a special attribute on the web method:

Step 2: Set useGetMethod=true while making the call

Here’s how you call the web method using Http Get:

Note: It needs to be a web service (.asmx). It will not work if
you use it on page methods.

Please see this page
in Atlas Quickstart for further info.

One of the easiest thing in Atlas is to use the
Page Method feature. If you use Atlas on your web page say
Default.aspx, you can directly call public methods on Default.aspx
from javascript. Just put a [WebMethod] attribute on a public
method in Default.aspx and then you can them from Javascript using
PageMethods.MethodName().

On the client side you can call this method like this:

Here’s the catch, Page method calls are always HTTP POST calls.
You can never make HTTP GET call to the Page methods but you can
make HTTP GET calls to Web service method. So, on later stage of
your project when you will need Http response caching in order to
save roundtrips, you will have to refactor all page methods to web
service methods and for this you will have to move all public
methods and related code from default.aspx to some web service. So,
try not to use Page methods from Day 1.