Sez : Dan Wilson     July 19, 2010 9:25 AM

I happened to be researching which platforms visit my web properties. I found some unexpected trends and thought some of you might be interested.

First, the obvious. Windows (the much maligned operating system) is firmly in 1st place with 85% of traffic.

In second place, Apple, with 7.4%. Then Linux in third, with 6.44%

Linux trails Apple by less than 1%?!?!

By mindshare and mouthshare, I would have thought Apple would command a much larger lead. Especially since I write almost exclusively on technology topics.

What trends are you seeing on YOUR web properties?

Sez : Dan Wilson     September 29, 2009 7:31 AM

I was trying to check in some changes on the Model-Glue framework and kept getting this error:

I updated from SVN, thinking it to be a synchronization error, but I still got the same error.

I used the 'cleanup' or SVN:clean functionality to maybe get the .svn files and such back in to the right condition, but that didn't help either.

The original SVN Comment I used was:

Can you spot the issue? I can't either. What fixed the error:

Was changing the multi-line comment to a single line comment. Once the comment was a single line, there was no issue checking it in. I'm not sure what I learned here, but I hope SVN doesn't REALLY have a problem with multi-line comments, after all, we need those to keep details on what changed!

Sez : Dan Wilson     September 16, 2009 7:51 AM

I often consider usability when using web applications, especially when I am the user. Our lovely state of North Carolina, is very tech savvy and has a lot of online resources and help. Did you know that North Carolina was one of the first states to have it's own data center?

Today, I went online to change my address on my Driver License. Apparently there is some complication with my particular license (hopefully not a warrant out for my arrest :-) ) in the system and I need to go into a physical office for human assistance. As an application architect, I can see this is probably some poorly handled data condition. I can dig that, a computer can't handle EVERYTHING...

What prompted this post was a bit of musing on proper error messages. When humans interact with computers, by definition there is a depersonalization to the process. This depersonalization can add a level of harshness or friction into the equation, altering the perception of the organization to the user. Allow me to pontificate...

I often stay at nice hotels. Nice hotels always have extremely polite front desk staff to help check guests in. The check-in phase of the hotel stay sets the stage for perception. If the registration desk is nicely furnished, elegant and staffed with ultra-polite staff, guests perceive the hotel as a nicely furnished, elegant and ultra-polite and this perception sticks with them the entire trip. If there is some reason why a request can not be accommodated, say I ask for a room on the top floor and the top floor has already been booked, the registration staff apologize effusively and find a suitable arrangement. Even if I asked for something impossible, like a helicopter to take my bags to my room, the staff would politely and softly apologize that such a service was not available, then offer the services of a bellman for bag delivery.

Hotels definitely understand the human touch. Computers do not. Nor do the engineers that create applications. See, it was perfectly acceptable for some reason or another not to provide algorithms suitable for handling an address change with my specific type of license. The engineer probably had a meeting discussing just such an occurrence and it was deemed not critical for the application. So the engineer dutifully put in code to catch such an occurrence and then added an error message to halt the flow of the application. The engineer considered the application from the perspective of the application and this is what was implemented:

Ouch. Nothing like a BIG RED STOP SIGN.

STOP! It says.. The text, actually, isn't half bad because it attempts to explain the issue, "...Multiple Address Records..." and offer to help me find the nearest office. But, I reeled from the impact of that stop sign.

To stick with the hotel analogy, it was as if I approached the registration desk, asked for a room with a King Sized bed, and the clerk said, "We have no king beds" then slapped me across the face, WACK!

I'm sure all of this seemed rather normal for the Application Engineer, who had undoubtedly seen this error page hundreds of times before during testing and was desensitized to it. Me, however, expecting to see a helpful page allowing me to change my address, was a little taken aback by the HONKING BIG RED STOP SIGN OF DOOM CLUBBING ME LIKE A BABY SEAL.

So, I mused a little bit this morning and made a decision to pay a little more attention to the human factor and to usability. I challenge you to do the same in your applications.

Do you have a screenshot example of a ridiculously insulting error message? Submit a link of the image to me and I'll post it here for the amusement of others...

Sez : Dan Wilson     June 9, 2009 5:17 PM

Kunal Saini, an Adobe employee, recently posted an article on Adobe Developer Connection about Performance tuning for ColdFusion applications. This is a well written article full of useful tips and practices and should be a must read on the topic.

I will raise a counter point to one of the minor tips Kunal raised. He says:

compare() and compareNoCase()

Use compare() or compareNoCase() instead of the is not operator to compare two items. They are a bit faster.

I trust Kunal has insider knowledge about the implementations of these two compare functions, because I fail to see how a straight evaluation (<cfif dan IS 1337>) can be slower than a function call ( compare(dan, 1337) IS 0 ). Maybe it has to do with the type inference and type conversion ColdFusion does as a dynamically typed language, maybe it is something else. Regardless I avoid using compare() and compareNoCase() because both functions reduce the readability of the code.

Whereas all boolean comparisons in ColdFusion treat 1 as true and 0 as false, the compare and compareNoCase functions return 0 if the comparison is true. This means compare( 1, 1) will return 0, which doesn't follow the boolean rules. Since this does not follow the rules, code using compare and compareNoCase is harder to read, harder to follow, and generally uglier than straight comparisons.

So Kunal, I don't take anything away from your statements and I appreciate you writing the article. I want to point out that software isn't all about micro-performance, it is also about long-term maintainability. Always write your code to be readable by others.

Of course, if you happen to write the next Facebook and you need to squeeze every possible fraction of a millisecond out of a routine, then throw this advice right out the window. But then again, you'd have already tuned every single query permutation, added a clustered caching layer, offloaded your static files to a Content Delivery Network and clustered your infrastructure Horizontally and Vertically, haven't you?

Sez : Dan Wilson     May 21, 2009 1:12 AM

I write from time to time on code quality and structure because it is a topic of interest to me. Clean code and well named logical structures, methods and objects really pay off during the infinitely long Support And Maintenance phase of software development.

Some could accuse me of having too many opinions on the topic, and I'd guess they could be on to something. Heck, I'll probably disagree with something I've said today, tomorrow, just because I'm always refining and learning.

While some of what I think/advocate/do is opinions, and could be subjective, I'd like to share some code I found on a project today and talk about the importance of method names.

A method should describe it's intent or behavior at the level of where it is inside the program. For example, a method named load() might be sufficiently descriptive to represent the behavior and be flexible enough to withstand a refactor or two. In other places in the program, perhaps the right method name is loadShippedOrders() since there will always be the concept of a shipped order in our proverbial system.

You get the point, right? There is a wide range of OK-ness for method names, with behavioral descriptiveness and refactorability as being two made up words that really judge the method name quality.

I found code today that really flies in the face of any of these principles. The names of these methods do not in any way describe any behavior of any system I've ever written, nor will probably be lucky enough to write.

method bodies removed to protect client interests

Be the Judge Yourself:

Before you ask, this code was found in a production eCommerce system that is currently running that has nothing to do with Phasers, Energization nor beaming anything to any location.

Sez : Dan Wilson     May 3, 2009 11:56 PM

Now Hear This!

This is a public service announcement. If you hard code scopes inside your CFCs (request, application, session), stop today.

I know it might be 'easier' or 'cleaner' or less lines of code, but you are really painting yourself into a corner when you do this.

An object (CFC) should not know or have access to ANYTHING outside of itself, its configuration and its immediate dependent objects.

If you want to question/argue with me on this, go for it. (Just go Read Up On Information Hiding before you do).

That Is All

Sez : Dan Wilson     March 2, 2009 6:11 PM

At 6:00 EST this Thursday, March 5th, I present Making Bad Code, Good to the Online ColdFusion Meetup. You can attend this presentation virtually, by visiting the Online ColdFusion Meeting Room at 6:00 EST.

If you work on a legacy application, or on code built by lots of developers over the years, you likely laugh your way through this presentation. I promise to be thought provoking and challenge the way you write code. In this session, we'll look at lots of code samples and walk through making incremental changes to speed development, reduce errors and make life easier for everyone involved.

Ideas and concepts in this presentation will help you improve your existing applications and write more maintainable code.

The recorded presentation can be watched now!

Sez : Dan Wilson     February 18, 2009 6:59 PM

The Law of Demeter is a Software Engineering principle guiding how objects should talk to each other. From Wikipedia:

The Law of Demeter (LoD), or Principle of Least Knowledge, is a design guideline for developing software, particularly object-oriented programs ...[and] ...can be succinctly summarized as "Only talk to your immediate friends." The fundamental notion is that a given object should assume as little as possible about the structure or properties of anything else (including its subcomponents).

We Don't Need No Stinking Laws

Now, I'm no fan of laws, so I privately refer to this as the General Guideline of Demeter, even though it doesn't sound as snappy or cool. However, just because there are valid reasons to break it, doesn't take away from the validity of the intent. Let's look at 2 code examples blatantly ripped off from the CFCDEV mailing list:

Conforms To Law General Guideline of Demeter

Violates Law General Guideline of Demeter

Ok, So What?

In the conforming set of statements, the room is asked directly whether or not certain things can happen. The implementation (steps required to complete the task) are hidden from the calling code. This is encapsulated and will help insulate callers from changes in the implementation.

In the violating set of statements, the calling code has to get a reference to Room, then ask Room for a Plan and then query the plan. Now calling code is expected to know about this Plan and what the plan knows. This adds another level of coupling and if Plan changes, then a whole lot of code has to change as well.

However, to the programmer, the violating syntax (Room.getPlan().canSelectStyle()) could make sense. It might be that the programmer doesn't want to refactor Room and using getPlan() is a faster way to do something. If the code works, is it wrong?

I Don't Follow All This Abstract Stuff. You Are Losing Me!

Ok, fair enough. My eyes glaze over with too much abstract stuff too. Let's look at an analogy.

I made a call to a credit card company. The essence of the call was:

CC Rep: CreditCardRep.answerPhone()
Thanks for calling Law Of Demeter Credit Card Company, how may I help you?

Me: Hi, My name is Dan Wilson. I have a question as to a charge on my latest bill.

CC Rep: Hi Dan, I'm Tracy. I can help you with that. For security purposes, what is your account number, mothers maiden name and shoe size?

Me: Acct: 333-444-555-5555 mothers maiden: Stratulat Shoe Size: 9

CC Rep: CreditCardRep.verifyAccountInformation()
     Perfect. What is the charge you wish to inquire about?

Me: I have a 17.99 charge to ILovePets.com on Feb 7th. I can't find my receipt so I don't know what this is for.

CC Rep: CreditCardRep.lookUpTransaction() From the transaction details, you purchased a red dog sweater. Do you recall that purchase?

Me: (Embarassed) Yeah. ok No problem. I also wanted to change my mailing address. Can you help me with that?

CC Rep: Of course, what is the new address?

Me: 123 ColdFusion Lane, Surf City, North Carolina.

CC Rep: CreditCardRep.updateAccountAddress()
     Ok. I've updated the address. Is there anything else I can help you with?

Me: No thanks. That takes care of me.. have a nice day!

CC Rep: OK Dan. Thanks for calling Law Of Demeter Credit Card Company. Have a nice day.

What Am I Supposed To Get From That Example?

Note how I called the CC company and talked with a representative. I only spoke to that representative and was not exposed to any implementation nor had to talk to any other objects to get my tasks done. Let's look at the converse example:

CC Rep: CreditCardRep.answerPhone() Thanks for calling Demeter Violation Credit Card Company, how may I help you?

Me: Hi, My name is Dan Wilson. I have a question as to a charge on my latest bill.

CC Rep: Hi Dan, I'm Tracy. I can help you with that. For security purposes, what is your account number, mothers maiden name and shoe size?

Me: Acct: 333-444-555-5555 mothers maiden: Stratulat Shoe Size: 9

CC Rep: CreditCardRep.verifyAccountInformation()
     Perfect. I can refer you to our Payment Inquiry Department. May I place you on hold?

Me: Ummm... ok.

CC Rep: Perfect. CreditCardRep.getPaymentInquiryRep() ......

CC Rep 2: Hello, this is Jessica, the Payment Inquiry ObjectRepresentative. For security purposes, what is your account number, mothers maiden name and shoe size?

Me: (Grumbles... didn't I already say this once?) Acct: 333-444-555-5555 mothers maiden: Stratulat Shoe Size: 9

CC Rep 2: CreditCardRep.getPaymentInquiryRep().verifyAccountInformation()
     Perfect. What is the charge you wish to inquire about?

Me: I have a 17.99 charge to ILovePets.com on Feb 7th. I can't find my receipt so I don't know what this is for.

CC Rep 2: CreditCardRep.getPaymentInquiryRep().lookUpTransaction()
     From the transaction details, you purchased a red dog sweater. Do you recall that purchase?

Me: (Embarassed), yeah. ok No problem. I also wanted to change my mailing address. Can you help me with that?

CC Rep 2: No, I am sorry. Our Address Change department handles that. Would you mind if I placed you on hold?

Me: (Grumbles, looks at watch) Ummm... ok.

CC Rep 2: Perfect. CreditCardRep.getPaymentInquiryRep().getAddressChangeRep() ......

CC Rep 3: Hello, this is Ann, the Address Change ObjectRepresentative. For security purposes, what is your account number, mothers maiden name and shoe size?

Me: (Grumbles... Kicks Dog) Acct: 333-444-555-5555 mothers maiden: Stratulat Shoe Size: 9

CC Rep 3: CreditCardRep.getPaymentInquiryRep().getAddressChangeRep().verifyAccountInformation() Perfect. What is the new address?

Me: 123 ColdFusion Lane, Surf City, North Carolina.

CC Rep 3: CreditCardRep.getPaymentInquiryRep().getAddressChangeRep().updateAccountAddress()
     Ok. I've updated the address. Is there anything else I can help you with?

Me: No thanks. That takes care of me.. have a nice day!

CC Rep 3: OK Dan. Thanks for calling Demeter Violation Credit Card Company. Have a nice day.

And What Shall I Gain From That Example?

I'm sure you have had a similar experience calling a credit card company. Did you feel like their processes were well designed? Wasn't it a much cleaner experience to just deal with the main object and let it handle the implementation of getting the tasks done?

Circling back to the Law of Demeter, note this passage from Wikipedia:

When applied to object-oriented programs, the Law of Demeter can be more precisely called the "Law of Demeter for Functions/Methods" (LoD-F). In this case, an object A can request a service (call a method) of an object instance B, but object A cannot "reach through" object B to access yet another object, C, to request its services. Doing so would mean that object A implicitly requires greater knowledge of object B's internal structure. Instead, B's class should be modified if necessary so that object A can simply make the request directly of object B, and then let object B propagate the request to any relevant subcomponents. Or A should have a direct reference to object C and make the call directly. If the law is followed, only object B knows its own internal structure.

So if I am Object A, should I really be exposed to the fact that the credit card company even has a Payment Inquiry Department or an Address Change department? Surely these internal details should be kept inside the CC Company Object, not sprinkled through all the various objects that interact with a Credit Card Company.

What Should I Take Away From This Nonsensical Post?

The call dialogue examples above are contrived, I admit, but think of the above dialogues as a set of design requirements for software. Now ask yourself the following questions:

• What would have to be updated in each of the designs if the CC company added an account verification department that validated account number, mothers maiden name and shoe size?
• What would have to be updated in each of the designs if the CC Company merged the Payment Inquiry department with the Address Change Department?
• Which design better encapsulates the implementation from the caller?
• Which design incurs less ripple effect from design changes?

Thoughts, concerns, comments? Add them below!

Sez : Dan Wilson     January 26, 2009 10:57 PM

There are a number of ways to speed up a website. An easy one would be to compress asset files and compact the files. This has been widely done for Javascript files with popular tools such as JSMIN and Packer.

The general idea behind compression/combination is to reduce the number of characters that must be sent over the wire as well as reduce the number of HTTP calls that must be made. Each time a browser gets a request to download a JS file, there is a certain amount of overhead incurred in negotiating and completing the HTTP request. Combining all JS files into one file is a great way to speed up a web application.

Everyone Already Knows This, Right?

Probably. However, CSS files can often be as numerous and verbose as Javascript files. How come there no public outcry for CSS compression/combination?

There happens to be a compressor/combinator that handles CSS files, the YUI Compressor. For most web application developers, YUI Compressor is an annoying tool to use because, as a java application, it must be installed and run from the command line. Yuck!, right?

Scriptalizer, developed by ColdFusion luminary Aaron Lynch, is a web front end for the YUI compressor. Scriptalizer has handled Javascript compression/combination for a while now and is a nicely designed, easy to use tool. Aaron recently added support for CSS compression/combination. Now, dealing with CSS files is as simple as dealing with JS files.

How well does it work?

I added all 14 CSS files from The Health Challenge and compressed/combined them with Scriptalizer. Here are the results:

• Number of Files Before: 14
• File Size of All Files: 35.42 KB
• Number of Files After: 1
• File Size of All Files: 19.96 KB

As you can see, the reduction was significant. Not only have I cut the size of my CSS assets by ~50%, I have also removed 13 HTTP connections.

Sez : Dan Wilson     January 22, 2009 7:05 PM

Another 500 Null Error / Solution

I ran into a strange error in the registration section of TheHealthChallenge.com where Internet Explorer users (Editors Note: Remove defamatory comments re: Internet Explorer Development Team and gratuitious comparisons about the size of their brains vs. size of their egos ) clicking a button would cause a 500 Null.

Here are the error details:

Can anyone venture a guess as to what the problem was? You want more information? Take a look at the form code as well:

Here is the HTML for the Form:

By the looks of the HTML code above, a single button will be drawn on the screen along with some friendly text. So why the error?

Solution

Apparently Internet Explorer does not handle serializing the form post if there is no content and what it sends to the server is not what the server expects. Possible resolutions for this are to remove the [enctype="multipart/form-data"] attribute or change the [method="post"] to [method="get"]. Either one will work as intended.

I happened to create this set of circumstances by using the CFUniform library in a way it was not designed for. I mentioned this to Matt Quackenbush who reworked the inner workings of the CFUniform Library to intelligently figure out if a file upload control is in the form or not. If one exists, the [enctype="multipart/form-data"] attribute will be included automatically. If you experience the 500 Null problem listed in this post, and you are using the CFUniform Library, simply update your version from http://cfuniform.riaforge.org/ and you'll be all set.