Damian Brady’s Blog

Yep, jQuery 1.4 has been released.

Here’s a great post from nettuts outlining some key differences and new features.

I don’t really have much to add on this, but just a few thoughts:

1. Speed improvements are good and all, but when you can get ten times better javascript performance by changing browsers, nearly doubling the speed of your .css() method not the most important thing. Still, I can’t expect the jQuery team to be able to retire browsers for people I guess…
2. A lot of changes seem to deal with allowing functions to be passed into methods.  Being a .Net 3.5 guy, I’m love this anonymous delegate stuff, so it’s good to see!

Yeah, that’s all the comments I have right now. Told you I didn’t have much to add!

It all started when I decided that I’d rewrite a partially-aborted PHP web app of mine in .Net. The PHP version was relatively functional, but PHP is not my strongest skill, so updating and improving it was hard. Combined with a lack of good quality free time, it meant that I didn’t have the inclination to update it much.

Much of the design work is already done. The database schema is solid and it isn’t trivial – it took me a number of iterations to get right. The UI flow has been decided, and at this point, I’m happy to reuse most of the layout, css and images.

At Tech.Ed this year, I heard a lot of great things about ASP.NET MVC. The Hands-On-Lab I did gave me just enough of it to get me interested, so when I decided I was going to rewrite this thing in .Net, MVC seemed like the way to go.

So I’m now attempting to learn how it all works, and it’s going really well. The secret? The NerdDinner tutorial courtesy of Rob Conery, Scott Guthrie, Scott Hanselman, and Phil Haack (actually I get the impression that Scott Guthrie wrote the tutorial, but the originating book is authored by all of them).

Seriously, if you’re looking at playing with ASP.NET MVC, run through this tutorial from start to finish. I guarantee by the end of it you’ll be all over the basics, and loving the way ASP.NET MVC is put together.

I’m looking forward to getting into some real development with this project.

You’d probably be aware that I’m a fan of Stack Overflow. I mean, I have my SO profile over there on the right of the page.

This is just a quick post to provide a link to the best response I’ve seen on Stack Overflow. And just to clarify, I mean best in terms of amusement. It gets a point across I guess, but wow is it creative.

So here you go: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454

In my travels, I stumbled across a blog post from Brandon Savage titled, “Why Coding Tests Are A Bad Interview Technique”.  While there are some points I think are fair enough, for the most part I disagree.  I’ll break down the major points so it’s easier to read.

Sending out Resumes to all available companies

Brandon mentions quite early on that his major gripe with these programming tests is that he doesn’t have time to do one for every company out there.  Every company. He’s applying everywhere.  A good developer shouldn’t need to flood the market with resumes.  If you’re any good, you should be able to be a bit more selective about where you apply.  Is the market really that bad that you need to go door-to-door begging for a job?

Writing a complete application as a coding test

In the comments, Brandon elaborates on this a bit further, saying that he’s actually had a company ask him to develop a complete database-driven, input-validating, emailing application.  Yes, that’s ridiculous and if it’s occurring more than once in a blue moon, then there’s a problem.  If a company is asking you to write an app like that just to get an interview, I view that as over the top and unrealistic.  Asking you to code up Fizzbuzz or a function to recursively search a directed graph? Not so much.

Look, as long as the code I’m writing doesn’t take me more than a few hours, and I really want to work at the company, then I’m willing to put the effort in.  If I’m flooding the market with resumes hoping for any kind of bite, then I’m probably not going to want to spend much time demonstrating my abilities to… who was it…? One of those places…

Asking for a code test is disingeneous and disrespectful

You know what? I totally disagree.  Brandon suggests that a few phone calls might be enough to determine whether someone is qualified.  Qualified? Yes, probably.  Does that mean anything? Not necessarily.

Let me digress for a bit.  I’m not sure whether the same thing exists in the US, but in Australia, we have a small training organisation that advertises late at night and promise a career in IT within a few weeks of graduating their four month course.  Four months, and they’re considered an IT professional.  These offers boil my blood – particularly because for many, many people, their qualification means the same thing as mine and my bachelor’s degree is therefore diluted.  By the way, I’m not talking about IT recruiters here; one would presume they’d know the difference.  My point is that an IT qualification by itself means nothing, and I’m not just talking about a participation certificate from Bob’s Discount IT Training.  I graduated from my degree with a scarily large number of budding programmers who couldn’t write code to save their lives.

Even experience on paper means nothing.  I’ve worked with plenty of highly qualified and very experienced people whose code just makes you cringe.  Sure, they’ve been involved in several major projects and have been an integral part of so-and-so really-important-deployment, but when you get down to it, they wrote crap code and nobody really knew any better.  You can look great on paper and still not have a clue.  I’m sure we’ve all known people like that.

Brandon suggests that as an alternative, asking for an already-written sample of code would be acceptable.  If it’s available, then sure, but I don’t think requiring one is fair for two reasons:

Firstly, the code the person writes during the day at their current job is not likely to be public.  As an employer, how would you feel about an employee showing the inner workings of your proprietary software to a rival so they can up and leave?  There’s almost certainly something in the developer’s current contract that explicitly prevents them from doing that anyway.  So what about code they’ve written in their spare time I hear you ask?  Unfortunately, not everyone writes code in their spare time and I think it’s rude to assume they do.  I do, and I’m sure a lot of developers do, but they might not for whatever reason.  You shouldn’t hold this against them.  Even if the person does write code on their own time, why should it be any more public than their company’s code?

Secondly, I’m not sure I’d be happy showing much of my own (old) code.  I look at stuff I wrote a year ago and wonder what I was thinking.  Does this mean I’m a crap developer?  No, I think it’s healthy to be able to appreciate that you’re continuing to learn.  If you can’t compare your current work to your previous work and see some improvement, then are you still learning?  I’m not alone on this line of thought either.  From a hiring point of view, I want to know how good the person is now, not how good they were the last time they wrote code that they’re allowed to show you.

It’s not all bad – what I agree with

I agree that it is very important to be able to see whether a developer is capable of learning. However, I’m not looking for the coding test to evaluate someone’s learning ability. A piece of code is a snapshot, and you’re not going to get any idea of learning and adaptability from a test like that unless you ask them to do it every six months for several years. You can evaluate whether someone learns well by asking them questions in the interview, and looking at how they keep up to date in the industry. You could even ask the default predictable question about a particular challenge they faced and how they overcame it. But nobody’s going to look at a slab of code and marvel at how well this person adapts to change. That said, if someone proudly hands you a bit of code written in VB.Net for version 1.1 of the framework using untyped DataSets, it’s probably safe to assume they’re not the learning-and-adapting type.

Brandon also suggests that if someone has a body of code samples ready to give out, then they shouldn’t have to do the test.  If those samples are appropriate and relevant, then I agree to an extent.  Why ask someone to redo something they’ve already done?  Really, though, if you want to see how well someone can think through a problem and turn it into code, then the best way to test that is to actually ask them to do it.

Summary (and tl;dr version)

If someone is applying for a job as a developer, I don’t think it’s unreasonable to ask them to write some code.  If it’s a fully-fledged application, or something that takes more than a few hours, then we’re not talking about a code test, we’re talking about free software.  Sadly, qualifications and experience don’t necessarily equal capability so you can’t just rely on that.  It’s entirely possible to have an awesome resume and loads of experience, and just be crap at writing decent code.  Being asked to show off your skills shouldn’t be taken as an insult, but an opportunity.

Sometimes you find a tool that’s not just good for run-of-the-mill, intended-purpose work, but also for fixing up some bad situations.  jQuery is one such tool.

Some work I’m currently doing involves presenting nicely styled pages to the user of a web site.  The html I have to work with is not always ideal and needs to be massaged.  Because I’m dealing with templates, it’s often simply impossible for me to change the html – I can only try to modify the framework around the bits of html I’m given.

Enter jQuery.

Provided the html I get is more or less xhtml compliant, I’ve got a Document Object Model (DOM) I can work with.  Using jQuery, I’ve found that I can manipulate this to my heart’s desire.

Let’s say I end up with an table which has an extra row between the header row and the first actual row of data.  No problem!

$(document).ready(function() {
    $('#mytable tr:nth-child(2)').remove();
});

And that’s it! Of course you may get a flicker of the incorrect display because we’re making the change only when the DOM is completely built, but we’re not really choosy in this situation.

Let’s try something a bit harder.  How about reformatting a table which contains a single column for debits and credits; the debits formatted with a red <FONT> tag.  And before you ask, yes, I’m serious.

We want this table to have a separate column for debits and credits.  Again, enter jQuery.

$(document).ready(function() {
	// first, deal with the headers
	var cell = $('#mytable tr:eq(0) td:eq(2)');  // look at the second cell (contains debits/credits)
	var w = cell.attr('width').substr(0, cell.attr('width').length-1);  // I know width is a percentage
	cell.attr('width',''+(w/2)+'%');	// half the width
	cell.text('Credits').before('<td align="right" width="'+w/2+'%">Debits</td>'); // split Debits and Credits header
 
	// now deal with each non-header row
	$('#mytable tr:not(:first)').each(function()
	{
		$(this).children('td:eq(2)').before('<td align="right">&nbsp;</td>'); // insert the new column
		var redVal = $(this).children('td:eq(3)').html(); // get current column value
		if (redVal && (redVal.toUpperCase().indexOf('COLOR=RED') > -1 || redVal.toUpperCase().indexOf('COLOR="RED"') > -1)) // if it's red
		{
			redVal = $(this).children('td:eq(3)').children('font').text(); // get the actual value to write
			$(this).children('td:eq(2)').html('<span style="color: red;"> '+redVal+'</span>'); // write to the debit column
			$(this).children('td:eq(3)').html('nbsp;'); // erase the credit column
		}
	});
});

Now this doesn’t give me beautiful xhtml, and I’m never going to feel happy about how this works, but it does the job.

Fun stuff.

I made a mistake the other day.  It seems that I used a random number when I really wanted a unique number.

Let me explain.

A service I wrote needed to send a message to an older process every 30 seconds or so.  To do this, it put a file in a particular folder and gave it an 18-digit filename.  Something like 541238740514861189.input.  The older process picked up this file, did what it needed to do, and put a corresponding response file back in the folder for my process.  Something like 541238740514861189.output.  My process picked up the response and continued doing its thing.  Fairly simple in theory.

I figured that seeing as this is a single-threaded process and it only runs every 30 seconds, seeding a random number with a time value would work.  I was even using the Ticks property of the DateTime which measures time in 10-millionths of a second.  It didn’t occur to me at the time that even though there was only one thread, there might be multiple copies of this service running.  Being a server with a multicore processor, that means that it’s possible for the same line of code to be executed at exactly the same time.

Still, it’d have to be phenomenal bad luck for the same line of code to execute in two processes within the same 10-millionth of a second, right? The odds would have to be miniscule!  Well, it turns out that while the Ticks property of the .Net DateTime might measure the number of 100 nanosecond blocks since the first of January 0001, that doesn’t say anthing about its resolution.  The resolution of DateTime is not 100 nanoseconds, it’s about 15ms.  Suddenly the chances aren’t so slim.  There are now only 2,000 blocks of time in that 30 seconds.

So yes, it was very, very unlucky for two of these service to generate the same “random” filename, but it was possible.  It was stupid of me to use a random number when I really needed a number that was unique.  They’re different things.  Solving the problem was as simple as making sure the first x characters of the filename represent the process Id.  That can’t be shared between processes so there’ll be no collisions.

Lesson learned.  Also, I should probably stop publishing my mistakes…

I solved a problem the other day.  It was a terrible solution. It works, but it’s difficult to be proud of how I solved it.

The problem was with MSMQ, but let me describe the problem with a needlessly overwrought metaphor.

Every week for the last 5 years, you’ve been sending a bill to one of your clients.  You have an infinite supply of envelopes and when Friday comes around, you print out an invoice, seal it in an envelope, send it by courier to your client, and a couple of days later, you get paid.  With me so far?

One day, you decide to start using a different invoice management software package – it’s much prettier and more stable than the old one.  You know, however, that the client doesn’t want anything in that invoice to change.  You’re not sure how they process it, but one time your printer smudged an invoice slightly and you didn’t get paid.  So everything in that invoice has to be exact.  Luckly, the new software is capable of printing a pixel-perfect version of the old invoice layout.  So far so good.

You also think you should start using a different courier.  Your existing courier company (COM+) is fine, but frankly they’re a bit behind the times.  The delivery drivers are about 80 and they’re driving some vans that are generations old.  So you set up a deal with a new company called C-Sharp 3.5 to do the delivery for you.

Still with me?  I told you it was overwrought.

So anyway, you give your new system a try.  You print out the invoice, compare it to the old one (spot-on, 100% the same), put it in an envelope, and send it off using the new courier company.

You don’t get paid.

You contact the customer but they don’t say much.  Just that they didn’t receive a valid invoice.  The new courier company swears they delivered it to the correct address and they provide proof.

You decide to try again next week and do some investigating.

The next week, you print out the invoice, compare it to the old ones (still the same), put it in an envelope, and organise for the new courier to pick it up.  This time though, you follow him.

He takes your letter, gets in his van, and drives to the client’s address.  He gets out, puts your letter in the mailbox and drives off.  Nothing wrong so far, as far as you can tell, so you wait to see what happens.

Soon, a guy comes out of the house (which by the way looks exactly like a big black box), opens the mailbox, picks the letter up, and takes it inside.

You go home, satisfied that the letter made its journey this time.  It must have been a once off.  But you still don’t get paid.

Again, you contact the client and all they’ll tell you is that they didn’t get a valid invoice.  You protest, telling them that you saw them pick it up but to no avail.

Over the next few weeks, you try everything you can think of to get this new system to work.  You try looking at the message again after it’s put in the letterbox and you try sending an invoice created by your old program.  Every time, the seemingly perfect letter gets picked up my the man in the black box, and nothing happens.

No matter how hard you try to work out what’s going on, nothing helps.  So, like any sensible person,  you give up and call the old courier company.  They turn up, pick up your invoice, and two days later, you get paid.  Despite the fact that they’re apparently doing exactly the same as the new guys, their deliveries get you paid, and the other deliveries don’t.  You resign yourself to using the old couriers until they or their vans all die.  It’s just a matter of time…

Fun story, huh?

So in case you’re a bit slow and didn’t work out what it was all about, I replaced an app that put a message in a Windows message queue for another (black box) program to pick up.  The old app was VB6 using a COM MSMQ library, and the new one was C# using the native .Net MSMQ library in the 3.5 version of the .Net Framework.

No matter how hard I looked, I couldn’t find ANYTHING different between the messages and where they got put.  I even dug up a copy of the black-box code and stepped it through a debugger.  When it got to the line saying Queue.Receive(), the message disappeared from the queue, and nothing came back.  There was no exception thrown!  I watched the message get picked up!  I did a binary comparison of the message contents from the old program and the new program!  No difference at all!  Inexplicable!

The fact that I was putting the message into the Windows Message Queue using a .Net library and picking it up using COM+ seemed to be all it took to break the thing.

This is the first time I can remember being absolutely, 100% stumped by what was going on.  I’d analysed what was going on as deeply as was practical and had come up with nothing.

So I did the logical thing and referenced the COM+ dll from my new app.  When I used this library to send the message, it all worked perfectly.

I really don’t like this fix. Despite the fact that everything works perfectly now, it’s still a failure in my eyes.  It’s like a brand new Merc with duct tape holding the wheels on.

However, given that I’d spent way too long already on something that really shouldn’t have been a problem, it was probably the right thing to do.  Cut my losses and take the easy way out.  I’m not proud.

I’m positive I’ve ranted about maintaining legacy code before, but I going to do it again.  At least this time I’m just reading the code so I can understand it and rewrite it rather than having to apply more bandaids.

Oh yes, and I’ve jumped on the “Top X List!” bandwagon.  It’s cosy up here.  So in no particular order, here are my top 6 things I hate seeing in legacy code:

1. Comments and variable names that didn’t update with the code

Yes, the code changes as you write, I understand that.  But seriously, can you please update the comments to reflect what you’ve done?

It’s very confusing seeing TODO comments for things that have been done, or comments about things that should be considered before the code goes into production.  Or maybe there’s a variable called currentIndex which is now actually a string containing a key because the original programmer changed from an array to a dictionary.

These things sometimes take ages to work out.  For example, I recently spent several hours trying to figure out what was happening in a chunk of code.  Looking at the following line:

It turns out:

1. It was in fact implemented (and was very, very necessary)
2. The failedMessageList variable contained all messages, not just failed ones

So seriously, if you change your code – take a glance at the comments to see if they need changing too.

2. Poorly named files

I had to add this one in. Not because it’s a big problem very often, but because when it occurs, it can be really painful. It’s obviously frustrating when classes and variables are named badly, but if files are named badly it can be even worse.

Let’s say you’re reading through the code and find a line that instantiates a Person class. Unfortunately, there’s no Person.cs (or whatever language) file. After some searching, you find that the Person class definition is in Teacher.cs – a file that wasn’t renamed when the code changed.

Or perhaps you’re looking for the UI for the window titled, “Database Maintenance” and have to work out that it’s actually a class called Restoring which is found in a file called FrmBackRest.vb. Sadly, a true story.

3. Inconsistent ways of doing things

I don’t have a problem if you do something a different way than I do; that’s fine – we all have our preferences. I might prefer to write to the database with parameterized stored procedures that I’ve written myself, while you use an ORM and just call a Save() method on an object you’ve just updated. That’s fine – both work.

What I really don’t like, though, is when someone does both. Like, in one place they’re calling stored procedures, in another they’re building SQL queries on the fly, and in another they’re retrieving DataSets via queries, updating the values, and calling a Save() method.

Nothing screams I-just-hacked-this-together-without-a-plan as much as large inconsistencies like this.

4. Even legacy-er code in legacy code

Sometimes I’ll come across legacy code that makes it clear that the original developer came from an even older background and didn’t quite understand this new technology. As a .Net developer, the most common stuff I see is good old VB6 code in a .Net app.

I came across a Goto statement in a bit of .Net code the other day. Another true story. It was a few lines after “On Error Resume Next”.

5. Error handling that hides errors

This is pretty common, and unfortunately it’s really only something that gets noticed when you have a problem. While things are working perfectly (and you don’t care how it works), there’s no problem. As soon as there’s an error though, you can’t find any details about it because the error handling is crap.

For example:

The end result of this? Here are some examples:

1. The transmitter.SubmitMessage method throws an exception. It gets caught, written to an error log, and thrown again. Ok, that’s not too bad…
2. The result from the SubmitMessage method comes back invalid. We increment our error count, get the details of the problem, and throw an exception. Then, oh no! That exception gets caught immediately, and another incredibly generic “CONNECTION_ERROR” exception gets thrown – completely abandoning the information gathered. But wait, there’s more! That exception then gets caught and logged and the error count gets incremented again! Yay! A “CONNECTION_ERROR” occurred… no more information… and an incorrect error count…

See? Don’t do it. If you can’t test for proper failures (sometimes it’s very hard), at least think about what’s going to happen.

6. Unused tracts of code

This one comes back to updating everything relevant when you have to revisit your code. A lot of the legacy code I’ve seen has codepaths that can’t possibly be used, methods that are never called, and in some cases classes, modules, and even entire libraries that aren’t referenced.

A recent project even had two code files, Connection.cs and Connection2.cs – they had different class names (Connection and Connection2 predictably), but they had the same methods with different implementations. Connection.cs was never used.

If you have to traverse your way through hundreds of lines of poorly-written code, it can get very frustrating when you find that half of it isn’t even used. It’s even more frustrating when you’re trying to match the behaviour you’re seeing with the code you’re reading, only to find out that it’s actually a completely different near-duplicate that’s running instead.

And that’s it – my top 6 annoying legacy code things. Feel free to comment.

My last post talked about how I wasn’t getting anywhere with my project.  Well now I am.

I might have mentioned that I’m using php and while it’s pretty easy to do stuff, I sometimes feel uncomfortable with the looseness of it all.  If you’ve used php in addition to a “real” OO language, you’ll know what I mean.  Lots and lots of globally-accessible functions with no namespaces, duck-typing, all that sort of stuff.

So I’m following some better practices (as suggested by Jon in his comment on the last post).  Nothing is very groundbreaking and I’m sure most newer php projects use the same kind of things.  Anyway, here’s what I’m doing:

I’m using an ORM library to get from my database to my code and vice versa.  Specifically Doctrine.  I’m reasonably familiar how these things work having used NHibernate for .Net (a port of Java’s Hibernate), but I’ve been impressed with how easy it’s been this time.  I got Doctrine working beautifully for my spider-web of a MySql database inside an evening with no experience.  I’ll let you know how it works out in the long run.  And yes, MySql is the database right now but Doctrine allows it to change very easily as expected.

I’m using an MVC pattern so my code doesn’t get too mixed in with my UI.  Now I’m sure there are plenty of libraries and frameworks out there that would help me with this, but I’m rolling my own… if you can call it that.  I’m used to .Net’s code-behind method so I’m really just copying that to an extent.  Each php page will have an include at the top that references the code-behind.  The “code-behind” php file will set up all the data and will provide functions that can be called by the front one.  Simple, but it should be effective.

Finally, I’m using JQuery for UI prettiness.  I had a serious look at a lot of javascript libraries and JQuery came out on top for what I needed.

So that’s it.  That’s what I’m doing.  So far it’s all fitting together quite nicely, but I’ll be sure to post updates if I want to rave about something or if something sends me into a fit of frustration.

As always, comments are welcome.

Damian

So I have this project that I’m doing for my own interest and I constantly find myself getting nowhere with it.  I’ve done plenty of design work and I have my schemas and stories sketched all over the pages of a notebook, but there’s nothing really tangible electronically yet.

The most common excuse I give myself is lack of time, but I don’t think that’s really true.  After all, I have tons of design work done and you’d think that’d be the boring part right?  I think the problem is lining up spare time, motivation, and resources.

Spare time exists in snippets everywhere.  When I’m on the bus, in a particularly boring lecture, at home after work, etc.  Motivation is more fleeting.  Sometimes I’m really keen to get into this project, other times it’s the furthest thing from my mind.  Finally, resources are either available or they’re not.  I haven’t had a laptop for a while, so I intended to develop mainly from home.  I’ve borrowed a laptop, but I don’t want to fill it with all my development tools.  Having said that, I’m doing it in php and I don’t need much of an IDE to cut code.  I could probably get some meaningful stuff done in notepad if need be.  Testing? That’s harder, particularly as I’d need a database running and a php web server.

So you see that even though I’m motivated more often than not, those three things don’t always line up well.  I don’t often have much motivation when I get home from work, even though I have time and resources.  When I’m sitting in a boring lecture, I’ve got plenty of motivation and time, but I don’t have the resources.  You get the picture.

So, how do I change this?  Well you’ll be pleased to know I have a plan:

1. I bought a laptop.  It’ll arrive in about a week.  It’s powerful and I can put whatever the hell I want on that thing so you can rest assured it’ll be running all the dev tools I want.
2. Portable Apps.  I rediscovered these when I was thinking about how I could improve the situation.  If a computer is available, I can spin up a full WAMP stack as well as GIMP, Notepad++, and FileZilla.
3. Target deadlines.  I have them.  And work breakdowns, heirarchical todo lists and all that stuff.  I’m organised.