DCOM from .NET

It's not well advertised but it is possible to use DCOM from .NET. It may not be as popular as the more recent RPC mechanisms but I still need to use it occasionally. So here's some C# code that should do the trick. The COM type library must be registered on the client machine. ComObject is the type of the COM object that you've imported into an interop assembly.

Type type = Type.GetTypeFromProgID(progId, serverName);
if (type == null)
throw new Exception("Unable to find the object, ensure the type library is registered");
Object objTest = Activator.CreateInstance(type);
ComObject comObject  = (ComObject)objTest;

Apple finally gets it

Apple have always annoyed me. Many many years ago the original Mac was ahead of its time but slowly Windows caught up and eventually the old Mac OS was looking pretty dated. But still the Apple zealots would ramble on about how great Macs were. We had one of the original iMacs but it just wasn't very reliable, even though it looked quite photogenic. Which was another reason for not liking Macs. Even though 95% of the worlds' computers were Windows PCs, every film with a computer always had a Mac. I recently upgraded that old iMac to MacOS X and was quite impressed. Of course the problem was all the software I wanted to run was Windows software so it wasn't much use to me, so it is still languishing in the loft. But first Apple decided to switch to Intel processors (and seem to have admitted in the process that they are much better than the old PowerPC processors). Then they released software to allow Apple computers to run Windows XP, which solves the major problem for anybody coming from the Windows world. And now they've released a laptop costing as little as £749, which solves one of the other major problems with the Mac, the price premium. It's still there but it's much less than it used to be and I have to admit that if I do ever purchase a laptop, I will now consider an Apple. And that iMac in the loft will be moving into my new office very soon.

A better link: search

I've known for some time that Google lies when I do a link: search to see which sites link to my sites. Even though I know of sites that link to mine, Google doesn't list them. So I was very pleased to discover that it's possible to use @: instead of link: and many more sites are listed, although it still doesn't show some sites I know link to mine.

An alternative to Environment.NewLine

Looking through my logs is always an interesting way to find out how people end up at my blog. One of the most searched for terms is 'Environment.NewLine alternative'. I'm not entirely sure why that would bring you here but anyway, what alternatives are there to Environment.NewLine? On Windows, Environment.NewLine is simply "\r\n", so you could use that, which would save a few key presses possibly (which is the only reason I can think of for wanting to find an alternative). If you're one of the brave people trying to develop a cross-platform app with Mono, then Environment.NewLine will be "\r" on Linux and other Unix platforms. So depending on what you're trying to achieve you may want to go with Environment.NewLine anyway or you may want to hardcode your newlines to "\r\n" or "\r".

Not Google site: bug

So after looking more closely at what I thought was a bug with Google, it turns out it's not. site:http://www.randompubfinder.com/ returns only the pages in Google's main index, site:http://www.randompubfinder.com returns all pages, including supplemental results. What are supplemental results? Basically pages that might show up in search results if Google can't find anything better. So we now have 4 pages in the main index! Unsurprisingly our hits are way down, since most of our traffic is driven by Google. So why did this happen? It seems that Google now won't store all pages in the main index if your site isn't popular enough. By popular, I mean having lots of inbound links. We don't so we get the big heave-ho. Doing searches now that used to bring up links to us now actually shows less relevant results, so I'm not entirely convinced this is helping improve the user's experience. Somebody at Google has written a fairly lengthy article about the latest updates there, with lots of unhappy people leaving comments. Here's a blog post from somebody in a similar position to ourselves.

Weather Bonk

Bonk probably has a different meaning in the US, but other than the strange name, this website is pretty good. I think it's pushing AJAX and Google Maps to its limits, as moving around can get pretty slow, but it has all the weather info you could ever need along with links to webcams. And even better, you can plug it into your own website in about two minutes.

Google site: bug

So there I am panicking because the Random Pub Finder seems to be disappearing from Google and today it got worse. Only 58 pages in the Google index apparently. Then I looked at the search string, site:http://www.randompubfinder.com/ So I tried site:http://www.randompubfinder.com and there are 639 pages. Panic over. So it looks like Google has a bit of a bug in its search engine and in Google Sitemaps, which provides the first URL as a link to tell you how many of your pages are indexed.

SEO made easy

I think I've made a reasonable job of optimising the Random Pub Finder for search engines. Our average hits are over three times what they were before I did any SEO on the site. I've not done anything dodgy and it's cost nothing. At this point I could claim to be a genius or I could tell the truth and just admit to reading this book. There are plenty of guys out there who will do the SEO work for you (for a price), but it's probably cheaper just to read the book. The disclaimer at this point has to be that the rules for search engines are changing all the time, so this book may well be out of date already...

It's a small virtual world

This image shows where the hits to my main website are coming from. I'm blown away by the fact that my crappy little site can attract hits from so many places on earth. OK, people mostly come from the US and Europe, which I guess is due to the higher levels of internet connectivity in those areas, but I've managed to get hits from every continent (OK, if you want to be pedantic I probably haven't had any hits from Antartica but Google Analytics seems to ignore it so I don't know for sure). My guess is that when air travel becomes too expensive for the average man in the street (which will be pretty soon I reckon) this kind of virtual travel will be the best way to see what goes on in the rest of the world.

The crazy world of Google

A few weeks ago the Random Pub Finder had over 600 pages indexed in Google, pretty much the whole site, then a week ago it was down to just over 200. Now its bounced back to over 300, but where are the other 300? Who knows. The site has hardly changed during that time so I don't think it's anything I've done. The more I learn about search engines, the less sense they make.

Milton Keynes are relegated

Football isn't generally any kind of morality play, good things don't always happen to good people and vice versa. But it did today. The most disliked team in England were finally relegated to the 2nd division. Why are they disliked? They uprooted the club and moved it across the country to Milton Keynes from South West London. This may be a common occurrence in the US, but franchising of clubs here has never happened here in the past. Why do I care? If they had been successful then they may have been the first of many clubs moving just to get a few more bums on seats and to hell with the club's fans. Not only that, but the club set up by the fans, AFC Wimbledon, is ten minutes down the road from our house. Unfortunately they missed out on promotion this year, but they are still one division closer to their nemesis.

Pennine Lancashire

If you're of a certain age and were brought up in the North West of England, Tony Wilson was probably a big part of your formative years. Not only was he constantly on the local TV news, he also ran one of the coolest record labels of the time and owned the hippest nightclub. Well now he's going to try to help regenerate the rundown parts of East Lancashire. This part of the world is close to my heart and it certainly has some things going for it, it has beautiful scenery, it's very cheap to live there and, OK, I can't think of anything else. Tony certainly has a bit of a challenge on his hands. The towns around East Lancashire have never really recovered from the industrial decline in the latter half of the 20th century. I went to school in Blackburn and of the people I've remained in contact with, only one still lives in the area. My family have also all moved away, so it's no wonder there's a problem with negative equity. I went to a pretty decent school, so all my friends are well educated and probably just the kind of people the area needs to help regenerate it. But they've all moved to well-paid jobs in the South East (except for one friend who's moved to Lancaster, one part of Lancashire that does seem to be doing quite well for itself). That's the main problem Tony needs to solve, getting these kind of people moving back to their roots. Manchester and Liverpool managed to recover from their apparent terminal decline, so I'm sure it will be possible.

Is AdSense worth it?

I added AdSense ads to some of my websites as an experiment to see if it would be worthwhile adding them to the Random Pub Finder. I've now been signed up long enough to get a reasonable idea of how much money can be made. Based on my earnings, which may not be completely representative, you can get anywhere between $0.05 and $1.50 per click. But Google don't provide any information about which keywords provide the high-earning clicks, so it isn't possible to optimise your site based on that, which would be a pretty lame thing to do anyway. Earnings per 1000 pageviews seems to be about $5, so I'll never make a living based on it, but I might make a little bit of pocket money. So how many hits would you need to actually pack in the day job? OK, say you need to earn $6000 a month (which may be a bit high or low depending on where you live and your lifestyle) how many hits would you need? That works out at $200 a day, or 40,000 pageviews. My guess is you'd need to be running your own server to handle that kind of load (I'm sure any free host would throw you off their servers before you got to this level) so that's another expense. I've no idea how much that would cost but if you are getting that number of hits I'm guessing you also need support people to ensure your server is always alive (unless you want to provide the 24-hour support...) so add some more for that. Guy Kawasaki, who says he's in the Technorati top 100, also says he gets upto 1200 pageviews a day, so it certainly looks like it would be pretty hard to get near the 40,000 from blogging, doing IT writing at least. And more popular subjects lke the sex publishing industry seems pretty well covered already (so I hear). So in conclusion, I don't think ads are likely to finance mine or your lifestyle, but they could provide some useful extra cash. And are they worth it for the Random Pub Finder? Not until we get so large we get kicked off our free host. It's only a matter of time...

Diabolical dialogs

Apparently Windows Vista will have a whole slew of new dialog boxes for us to contend with. This is all in the name of security so perhaps there is some reason behind the apparent insanity, but us programmers have a bit of a soft spot for dialog boxes and our users don't. For a programmer, a dialog box is often the easy way out. What's the alternative? It depends on the scenario, but the typical situation where we would consider popping up a dialog is when the user is about to do something that could lead to some kind of data loss, so we throw up a dialog saying 'Are you sure?'. The alternative here is to have some kind of undo functionality and that can be pretty tricky to implement. So why don't users like dialogs? Because they interrupt workflow. The user is merrily going about their business when up pops a dialog and they have to think about the answer. After a while of course they learn to ignore the dialog and just hit the Enter key, which is another problem with dialogs that popup too frequently. They lose any effectiveness they initially had. Another problem occurs with multitasking. In one application I use, loading a document takes some time, so I open a file, then switch to some other application. When I flip back to the original application, there's a dialog asking a dumb question... So how do we get rid of them? First, remove any dialogs that serve no purpose at all. Examples of these are dialogs that merely say 'I've completed task X'. What is the user meant to do? Congratulate the computer? Next, find dialogs that 99% percent of the time serve no purpose, the 'Are you sure?' dialogs and just do what the user asked for but allow them to undo that action. Then look for dialogs that ask a question that invariably has the same answer. Add a checkbox that says 'Always do this and never ask me again'. You may decide that you want to provide a way of turning this back on, but have you ever needed to do it? I'd go even further at this point and suggest looking at any modal windows in your application and see if you can make them non-modal. Modal windows make user interaction more difficult, even though they make programmer's lives easier. If a user is likely to want to copy and paste between windows in your app, make sure they are non-modal so they have some chance of doing so. But I don't have an original bone in my body. All these ideas come from the great book 'About Face', that everybody should read.

Serialization in Delphi

One of the few visitors to this site came here looking to learn how to do serialization in Delphi, so I thought I'd oblige. Fire up Delphi, create a new Windows Application project and add a button and a memo control to the form. In the event handler for the button, add some code as follows- procedure TForm1.Button1Click(Sender: TObject); var LStream : TMemoryStream; begin LStream := TMemoryStream.Create(); LStream.WriteComponent(Memo1); LStream.Position := 0; Memo1.Text := ''; LStream.ReadComponent(Memo1); LStream.Free; end; Now run it and hit the button and, er, nothing happens, which is exactly as it should be. This just shows that the memo control is getting serialized to the stream, the text in the memo is getting cleared, and then the memo is getting deserialized and the text is getting put back. And that is about all there is to it. To add a bit of excitement, add another button and another memo. Add the following code to the event handler for the new button- procedure TForm1.Button2Click(Sender: TObject); var LStream : TMemoryStream; LStringStream : TStringStream; begin LStream := TMemoryStream.Create(); LStream.WriteComponent(Memo1); LStream.Position := 0; LStringStream := TStringStream.Create(''); ObjectBinaryToText(LStream, LStringStream); Memo2.Text := LStringStream.DataString; end; By default, Delphi serializes objects in a binary format. The ObjectBinaryToText method converts it to a human-readable form and there is another method to go the other way. Recognize the text format? It's the same as Delphi uses for storing DFMs. The serialization support in Delphi was developed purely for the IDE, which is why it's only really a half-arsed implementation. The only properties that will be serialized are published ones, which will likely limit what you can do with it. Of course, there are all the problems with serialization you should consider before you start using it. There's a whole lot more to serialization than this, but I hope this has been a useful introduction.

What is wrong with visible instance fields? Part 2

My previous post about visible instance fields actually got a comment, which is my first ever proper comment, unless you count the ones from my brother. Not only that, it actually got commented on by a member of the FxCop team at Microsoft. Crikey! I think that lifts me up from being a Z-list blogger to what, a Y-list blogger perhaps. Anyhow, the comment was that although moving from a visible field to a property won't break source compatibility it will break binary compatibility, which is a fair point. You can see this if you look at the IL for setting a field value compared to setting a property (via our old friend Reflector). ldloc.0 ldc.i4.1 stfld int32 ConsoleApplication1.Thing::Field ldloc.0 ldc.i4.1 callvirt instance ConsoleApplication1.Thing::set_Property(int32) So in some ways it will also break source compatibility if someone is using you class library from an IL application, if there are such crazy people around. But I think this does highlight a problem with FxCop. It was originally designed to help the .NET Framework team find problems in their code. But the kind of problems they need to worry about are not the same as what most programmers need to worry about. Mostly I don't care about binary compatibility, although I can see there will be companies doing component development who do need to care about it. Yes, I can turn off warnings that aren't of interest, but there are so many warnings in there, it's pretty overwhelming to even know where to begin. Perhaps I'm asking too much, after all FxCop was designed for people writing class libraries, but the fact it now ships with Visual Studio 2005, suggests Microsoft are now thinking application developers should be using it as well. If MS do think this, then I think they need to start thinking about having some different modes of operation in there for different use cases. As an example, it would be great to throw an application (ASP.NET or WinForms) at it and it to tell me which public code never gets called. It doesn't do this now, because it doesn't know who's going to be using the assemblies, but if the assemblies aren't shared with other applications then it should be able to work it out. Now, that would be cool...

The fear

When programmers start out they are like small children, they have no awareness of danger. So they just go ahead and hack code, with no thoughts for the consequences. It's only after a few late nights caused by introducing serious bugs due to a one line change for some minor cosmetic problem that programmers develop the fear. The fear is a good thing, it helps us programmers to spot potentially dangerous changes to code and try our best to reduce the risk of breaking things. But there are two main ways that programmers (and managers for that matter) will deal with the fear. The first approach is to try to limit the amount of code change. If they are fixing a bug in an area they are unfamiliar with, they'll try to find the smallest amount of code they can change that fixes the problem, so rather than try to understand what the code is trying to do, they'll just shove in something that fixes the problem for this specific case and move on. This approach has some merits, there is certainly a link between the number of lines of code changed and the chance of new bugs being introduced but it doesn't solve the underlying problem, that the programmer doesn't understand what the code does. If they did, the fear wouldn't be so bad and they'd likely fix it properly. In the short term, that bit of code probably just got even more difficult to maintain. In the longer term, areas of the product can become no go areas that haven't been touched for years and nobody understands anymore. But they work mostly so that's OK, until a new feature needs to be added. At which point, the developers will turn round and say "we need to rewrite it all because it's such a mess". So how else can we deal with the fear? What you need to do is get into a place where the fear holds no, er, fear. It starts off simply enough, get some source control in place. If you haven't got source control, you're pretty much screwed, unless you're working on the next 'hello world' app. It's a great thing to be able to check out some code, hack it around, then if it doesn't work out go back to what you had before. Or two weeks down the line, when you realise that the bug fix wasn't such a big success, you can rollback to something that's more sensible. Check in regularly, like twice a day, not every two months. There are lots of other things to help reduce the fear. If it's code you don't understand too well, try to work out what's going on, do a bit of refactoring, try adding some unit tests, throw FxCop at it (or in the Delphi world Pascal Analyzer), adopt some agile methods, get a QA team. The tools are out there, so lose the fear.

What is wrong with visible instance fields?

FxCop rocks, in a kind of hectoring school teacher kind of way. It complains about loads of things that are only relevant if you happen to be developing a class library that will be used by 3 million developers using every conceivable .NET language and in every human language known to man. But us mere mortals are mainly developing code that might get dumped onto one web server if we're lucky. But FxCop still helps out on stupid things like code that never gets called and visible instance fields. Except, what's wrong with visible instance fields? OK, making fields public that users of your class never need to access is pretty dumb, but how does a public field differ from a property with simple getters and setters? The FxCop help says "the code in a property's accessors can change as the type's features expand without introducing breaking changes." But if I need to change a public field to a property, how will this cause a breaking change? Fields and properties are used in exactly the same way by client code. The only explanation I can think of is that it may cause serialization code to break, but serialization code breaks all the time anyway so that doesn't seem particularly relevant. Saying all that, I'm still going to continue to use properties, if only to stop FxCop complaining.

Another tech bubble?

In the late 90s, things went a little crazy. We had websites popping up here, there and everywhere that allowed us to do lots of exciting things, mostly for free. It turned out that this kind of business model wasn't generally very successful so most of these sites went bust. At the time, being an IT professional was pretty good, since the job market was red hot. Then suddenly in 2000, it all went tits up. So here we are in 2006 and the job market is moving very quickly upwards,lots of new websites are popping up doing lots of exciting things, mostly for free, many with a business model that seems to entail nothing more than ad revenue, or value added services. So is this another bubble or is this different? It seems to me the key here is the growing online ad business which is doing very well at the moment. It seems slightly crazy to me that I can get paid $1.50 just because someone clicks on a link on my site (and the advertiser is paying even more). If that stream of revenue stops or severely reduces, a lot of these new web businesses might start having problems I reckon.

Virgin Wines are spammers

I can't remember how it all started. I think I entered some competition that offered the chance to win some free wine (how could I refuse?) and Virgin Wines got hold of my email address. Soon I was getting an email every week or so exhorting me to purchase a case of wine. I've no idea whether Virgin Wines provide decent wine or not, but the fact I've got a Majestic Wines about five minutes away means I wasn't tempted to purchase anything from them, so I sent an email to unsubscribe@virginwines.com (after all they are reputable company, right?). Then, nothing. the emails kept coming. So I sent another. And the emails still didn't stop. Then I got an email from the founder of Virgin Wines, not apologizing but offering me more wine to buy. So I replied directly to him telling him his unsubscribe functionality didn't work. I then got an email from Customer Services saying "Thank you for contacting Virgin Wines and we have arranged for the email address you have provided to be removed from our mailing list which will be actioned within the next few days.". So that was the end of it? Well, no. I then received what looked like a personal email from the founder saying "Dear Christopher I thought that, as we were warning our staff not to lose out on last weeks free case offer, we should do the same for you!Please don't hang about - when the free cases are gone, they are gone! Go to www.virginwines.com/reminder9 Cheers, Rowan Gormley Founder Virgin Wines" I presumed I was actually being offered some free wine at this point, perhaps as an apology for all the emails. But looking at the offer showed it was just another attempt to get me signed up to Virgin Wines. OK, I'd get a free case but only if I bought another case... OK, the price looks pretty reasonable, coming to just over £3 a bottle, but my corner shop does a nice red at £10 for 3 bottles. Then today I got yet another email offering me more wine at bargain prices. Frankly I don't care how good Virgin Wines are, they are spammers, so I will not be buying any wine from them, ever. And perhaps their PR department will see this and realise their mistake. Or they'll sue me...