Author Archives: RhysC

DBC within the C# language – Spec#

Posted in Best Practices, Design By Contract by

Spec# or SpecSharp
I have been hoping for something like this for quite awhile. I am hoping this will be something that will aid in compile time assistance for Design By Contract programming.
I have been looking into third party apps and even building my own libraries, however what i really wanted was compile time errors as opposed to run time errors, which although Test would usually find, don’t really help other developers as they leverage of my code.
Currently i have comments and run time checks however this still does not force consumers of my method to adhere to the contract, it only throw run time exceptions when they break the contract. the benefit here is they fail fats and they get a more meaningful exception message as to WHY the parameters are not valid. But it often also means that i have code the looks like:

public class Foo: IFoo
{
public void Bar(object param1)
{
Check.IsNotnull(param1, “Foo.Bar: param1 can not be null”);
if(param1 != null) //***this line is effectively redundant
{
//do something with param1…
}
}
}

The null check is still in place to prevent FXCop errors arising by not checking for the objects state before using it.
I really hope the Spec# C# additions will aid in this.

When is a bug not a bug?

Posted in Best Practices, communication, motivation, Productivity by

I am sure the Tester at the place I currently work at secretly hates me. He is far too nice and far too professional to ever say… but i am sure of it.
He is in a position where he knows what the application we are building should do and how it should do it. Unfortunately this is only ever communicated to me after I have built the module. He doesnt write the use case so dosen’t get a chance to prewarn me.
These changes are raised as bugs (as we only have the concept of bug, no concept of a change request) and so it looks like my code sucks as i have a couple of dozen bugs logged against my name (which is standard across the team). I dont like the idea of my code sucking. While looking through the buglist today, after reading the first 12 and realising that they were either A) Not bugs, but changes or B) not my bugs to fix; I got a little stroppy.
*begin blowing trumpet*
Now, when I get a use case I assume that this is what is required… I know, what an idiot… so I write my unit tests and do the whole Red, Green, Refactor like a good TDD agile boy,
*end blowing trumpet*
however I forget that we only call ourselves agile we are in fact… dreamers.
Huge numbers of tests fail and are left unattended, iteration after iteration… our scope is non existent.. our use case are guesses at what we kinda, maybe want and are completely ok to change at any time with the expectation to deliver on time still intact.
So I have tried to push back.
-A bug is raised
> If in use case ==> FIX NOW!
>Else ==>can be done in next iteration and is logged as “Not in spec/Functional change”.

I thought this may rustle some feathers and hopefully means the uses case would be a little more robust. It also means the actual bugs got higher priority, as I think they should.
No…
Now we just do non-functional iterations where we do “bug fixes” on all the functionality that was never originally asked for.
As there are a few developers (6-12) all on UK rates (not exactly cheap) and one BA (still only UK rates, but only 1), I would think it would make sense to focus the effort on the up front work, hell maybe even hire another “BA” so the development team don’t have to handle code 2,3,4 + times.
It also means the teste (again on UK rates) has to test and then retest every time the change is made… how do you spell D.R.Y???
To say this annoys me is somewhat of an understatement. It is pretty hard to be focused and passionate about what you are doing, knowing full well in only a few hours/days/weeks it will all get thrown out because someone threw together a Use case, with out putting more than 5 minutes thought into it.
More time scoping => less time “bug fixing”*

*i.e. retrofitting missing functionality

Now I know Agile encompasses the ability to “handle change”, but never getting the original scope correct… ever, through laziness, is not Agile, it’s just software cowboy bollocks.

Unfortunately nothing is going to change. This could be a really good project, even a flag ship project for the company as it is using new exciting tools for the comapny (.Net 3.0, Nhibernate etc) and it would honestly only require the smallest extra bit of effort. But it wont and that’s a shame.

end of yet another rant…

Apache.org = 404

Posted in PITA by

It really pisses me off that anytime i try to get something from Apache there are 404 error all over the show. I normally use Nlog, however at work we are using Log4Net. I went to the log4net site and most of the links i click on a dead… 404 bloody everywhere.
PITA!
As such i continue to use pretty much no Apache api’s in my dev.

…and the downloads are 1.1 that dont run… NLog has just cemented its place in my toolbox.

XBox

Posted in xbox by

Yeah I had to get one.
At the apartment we have a huge HD screen. Gears of War and Assassin’s Creed are awesome on it.
This thing blows my mind, the graphics are unbelievable… clearly I have not been up to speed on gaming or HD tv’s….

I am addicted to the creed… stealth kills.. I feel like a bad man 😉

DSL’s and tearing up tiers

Posted in Boo, Volta by

Boo:
I read a lot of Ayende‘s post, well actually I read everything he puts out, so as he references his work with Binsor and Brail (which are Boo off shoots/DSL), I figured I had better see what its all about. Well I am still getting my head around things, I haven’t learnt a new language in so long (shame on me). However I can now see why Bindsor would be so handy. I am not a huge fan of strings and XML to me, is one massive string. If i can get compile time checking AND get the flexibility of easy config. Sweet. Another thing on my massive to do list DSL up my configs.

Volta from MSDN labs is out… another thing I need to play with. Could be great for small teams teams if it works… after reading the blurb i am wondering if this is stepping on CSLA.Nets toes?

Coding style and preferences

Posted in Best Practices, Encapsulation, events by

There are a couple of things i try to keep in mind when writing code, well they is plenty but specifically for this post 2.

Re-usability and Reliability.

I do all that I can to fail fast. I want my errors to come up as I type, ideally your IDE will support you on this, if not plug ins like ReSharper help. Other wise I want build errors to tell me, “Hey mate your code is junk this does not make sense!”. The last thing I want is run time errors. This is not obviously shared with others.

In my mind using strings for business logic is a last resort and if done there are always constants.

Casting is also a last resort, and usually only done from a know parent class to a subclass.

I would much rather use enumerated constants, generics, type checks to perform this business logic or flow control.

i have spotted in a few place where effective type checks are being done using string

if( Object.symbolX = “Fully.Qualified.Name.Space.ClassName”)
{…}

if some one changes that name space then every check now has to be changed and the compiler will not pick it up.

it would have been just as easy (actually easier) to write

if( Object.symbolX = typeof(Fully.Qualified.Name.Space.ClassName).Fullname)
{…}
or even just do a bloody type check!

Secondly re-usability:
I am currently working as a contractor on an application that was many many week behind schedule largely due to an over worked non functioning UI. Myself and another contractor worked very hard to rebuild the UI framework (ie throw all the old stuff out and create new projects for the client side!) We knew it didn’t have to be the best looking code it just had to work so the the user could see the application. 14 weeks and no visible app is pretty bad. 2 weeks later we had a app that functioned, very basically but you could so stuff. We are now almost up to schedule (6 weeks to catch up 14 weeks with 2 guys fired is not too bad).
The other developer who I wrote the UI framework with was reworking some of my code and asked if he could change (or overload) the constructor so he could inject the views controller into the view. I explained I prefer not to as it means the view become more tightly coupled with the controllers and I don’t want the views to know anything other than they are Win or Web Forms.
I could understand were he was coming from, calling the controller from the view means its is easier and faster to write code. ie to save from the view just type this.IXXXXController.Save(XXXXX);
His points were valid. It is easier to code against, it is kinda loosely coupled as the View only know of the common interface assembly. I was starting to doubt why I go to the bother of creating events and delegates and event handlers (even most of them get reused)…..
Then I had to make a change to a view and i realised why I follow this.
Raising events means that ANY controller can use the view. i am reusing a lot of my views. Having knowledge of the controller leads to spaghetti code….. as the other developer i currently work with is a pretty good dev I am not really worried that he is going to go down that path, worst come to worst we can retro fit the events when/if we get the time. However when we got another contract dev involved, it went pear shaped fast. He is gone now, thank god.

Benefits of using events

  • They can go on your interfaces
  • As many other class can subscribe to the event as needed
  • separation of concern
  • Changing the EventArgs doesn’t change signatures of events meaning you wont break the build (provide nothing of importance is removed!)
  • Its clear where calls are coming from and where they are going. If i see a method in my controller called SuperView_RhysKicksAss(object sender, AssKickingEventArgs e){…} it is pretty obvious where this method is being fired from and why it is being fired (because I am Kicking Ass!), but you may want to check it is actually assigned a handler if you didn’t write the code…


Negatives

  • You have to write your EventArgs and Event Handler. This is perceived as a headache to pretty much everyone i have worked with. When I explain the xxxEventArgs is just a DTO and the handler is a one liner they usually easy up a bit. BUT it is still an extra dozen or so line that need to be created.
  • Its easy to write sh1te event code if the devs are not aware of coding standards, meaning it is hard to understand what is going on. Follow conventions to save headaches later
  • testing frameworks offer crap support for testing events

After weighing it all up, i think for the mean time I am going to stick to events when calls need to go out of scope.

Todo list

Posted in stuff by

As always there is far to much stuff happening in the world…. I need a list!

Languages I want to learn (or at least learn more about):

  • Erlang
  • Boo
  • IronPython/Ruby

Things I want to play with:

  • VS 2008
  • Cruisecontrol.net (I have never actually implemented it myself.. which is bad)

Stuff I have been playing with recently:
Oracle. Its a big beast and is really quite different to MS/MY/T SQL. But I can see why it is the dominant RDMS…
Things I Don’t like about my Oracle experience:

  • PL/Sql Developer by Allround Automations. I sucks and doesn’t handler cut and paste functions properly (e.g white space characters it doesn’t recognise breaks the code… why not just remove them?!?)
  • Shit schema’s are not just the domain of T-SQL… they are everywhere 😉 hehehe

MonoRail. The original MVC web platform for Asp.net. Its pretty cool, i have just built my new site, www.FullStack.co.uk on it and managed to get it together very fast, including the learning curve. Will i continue to use it? personally i have never really had to many issues with Viewstate and PLC. I don’t put a lot of logic in my code behind so don’t get in to too much troubles there.

PostSharp: I like it. It is a cool little AOP IL weaver that made my logging stupidly easy. Was going to try to add security with it too, probably wont tho…

Every day i would spend at least 2 hours read technical content, but mostly articles blogs and forums. I really don’t read enough books…So lately i have been catching up on my essentials list.

Books I have just read:
The Pragmatic Programmer. Its hard to believe this is almost 10 years old. Sure it has been revised and there are some old references to languages like small talk (as opposed to newer languages like c#), but this is as relevant today as it ever was. Thoroughly recommend it.

Head First Design Patterns: I really wish i read this before GoF and Fowler… it makes the whole process a lot easier. I must say i felt like a dick buying the book as it feel like a high school book, but it is well worth it… i did make up for by buying Slash’s Bio and the Flight of the Conchords dvd… sweeet.

Books i want to get
Erlang and NUnit from the Pragmatic series. I unit test every day but i would like to see “How Correctly” I am doing it. The xUnit testing book just far to big… its like 900 pages, come on…

On a side note; well done to the ever growing Open Source guys* that are getting snatch up by M$. Its nice for them to finally get some financial reward and its good to see M$ backing the real drivers of the community.

*Specifically Rob from Subsonic and Alex from Base4, but there seems to be many others at the moment too

Dependency on self?

Posted in Best Practices by

I am worried that DI is the new singleton. A pattern with good intentions and fantastic helpful when used properly but slipping into the realm of the abused.
Wehn leaving Australia i was working on a project where there where dozen and dozens of unnessecary singletons. they really just ahd no reason to be there other than to slow things down.
Recently i have seen in quite bit of code using “constructor injection”, no problem. But when you are passing in a object and then make this object dependent yopu are in effect providing circular references. However using interfaces this is allowed.
eg

My problem is: why?

I am seeing this specifically in the MVC pattern.
I dont need my views to know anything about my controller, so why pass the controller in as a constructor parameter. if it need to communicate with the controller raise an event, if the controller cares about this event it will subscribe to it.
I belive people are dodging using events because it seems tricky and DI is “cooler”.
bollocks to that I say.

Strings

Posted in Best Practices by

Strings are really beginging to annoy me. People need to think when they design API’s if strings are really the best thing to use.
String are for reading, for humnas to read.
I am using a system where most of the strings should be replaced with enum or custom value. the reduction in runtime errors would be significant.
i have to campare time code in one exapmle, these are in string format. i now need to know and understand the other applications time code format so i can do a comparison instead of using
if(timecodeA > timecodeB)
{
//DO LOGIC
}
which would be the logical thing to do.