Zenji Web Development

Andy produces more artwork than I would believe possible from one person! There was an obvious requirement to create a stylish and easily updated portfolio for his work. The site was developed using the CakePHP framework and layouts created by Ben of Radio Design. Check out the site at www.andy-potts.com.

I only just noticed that there’s a blogging app for Wordpress on the iPhone. It happily gets around the problem with Safari not allowing image uploads.

There is an issue with using the following code in an action filter:

which is a bit of code quite common in an authentication filter. The problem is it will throw a ThreadAbortException as soon as you put your code on a live site resulting in the error page for anyone who is not logged in. This is probably not what you want since you are attempting to redirect them to the login page.

Now it is a little unfair to say that it’s an issue because that is the intended functionality. But it doesn’t fit well with MVC controllers, especially since Microsoft’s official suggestion is to set the endResponse flag to false. That is just downright misleading since your controller action (which the filter just decided you can’t access) is still executed after the filter fails authentication – resulting in the action code being executed anyway whilst you see the login screen on the browser and assume it all went swimmingly! Meanwhile those files that this user shouldn’t have access to got deleted.

Yeah, that’s what I just did during testing whilst proving to myself that you can’t fake the URL as a non-registered user. Imagine my surprise. It’s true that the chances of a malicious user actually working out the URL might be low, but that’s no reason to leave the door open.

Oh, and your unit tests probably won’t catch this because the filters don’t get executed by the unit tests. But I digress…

To cut a long story short, this bit of code in your base controller (assuming you have one, otherwise stick in in all of the controllers) will prevent the issue:

It’s hard to believe how badly this is handled in IIS. Admittedly I’ve only tried it in IIS 6, but I see no evidence that it gets any better in IIS 7.

So here’s the problem – you create a website that allows the upload of images (or any file types for that matter). It’s very likely you’re going to want to limit the size of those uploads or you’ll end up in a world of pain when your users go and use up all your disk space. By default IIS allows upload sizes of 4Mb which is ample for image purposes. However, if someone uploads a file above that size you’re likely to want to notify them by telling them gently they’re an idiot for not reading the note above the file input field and then allow them to reselect a file.

But you can’t because the requests never gets to your page. IIS simply drops the request and seems to respond with nothing at all. That leaves the user looking at a ‘Web site could not be found’ error, which is misleading and just plain wrong.
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This is something I think is particularly poorly documented for the MVC framework. It took me a long time Googling and, in the end, guessing in order to get it to work correctly (and it’s still not how I’d like it, but there you go). Simply put, this is the code in the Controller:

And this is the code in the View:

I know it’s still only in Beta, but I think it’s time some of the Microsoft boys tidied up their otherwise useful blogs to remove and update many incorrect usage instructions for the latest cut of the framework. After all, it’s the only documentation we have at the moment.

One more issue I’ve found is the name that is assigned to the resulting <select> tag. It’s a bit irritating as I may not want the name to be the same is the key that is used in the ViewData (which is what it uses here, i.e. “PortfolioSelectDropDownList” in my case). That messes up my typed view. The only way I’ve found around this is to use the name of the variable in my typed view for the ViewData key, e.g. “Project.PortfolioID”. The result is that I get a select list and when the form is posted back my Project object is populated with the selected value.

To be honest it has a certain elegance to it so it may even be the intended usage! Still seems a bit strange to me though…

One of the big problems with the early adoption of any framework is the documentation. No books are released yet, if they are ever going to be, and so turning to Google is your best bet. In fact it’s your only option and my own preference is using Google over books anyway.

But frameworks change during development and you come across the issue that all of the top hits for your query are based on previous versions. When that previous version did it differently you’re stuck! I had this problem today when trying to create strongly-typed views. I love strongly-typed anythings, but I’m just a sucker for having a project that is more likely to work when another developer makes an edit and doesn’t bother fully checking the effects of their changes. It’s another safety net, and I’m a sucker for safety nets as well.

So, this is how I did it in bite-sized chunks. First the controller function:

Next I created a new view by right-clicking the above method (bear in mind that I’m using Visual Studio 2008) and checking the ‘Create a strongly-typed view’ before entering the full name of the object type (ContentClass). That produces an aspx.cs which looks something like this:

So far so good, but where I really came unstuck was actually using this in the view. Turns out it’s simpler than ever. All you need to use is the ViewData.Model parameter, which is automatically typed to whatever you set the view up as previously:

All that I have to do now is pass that through to a UserControl. I’m assuming I can strongly-type those as well. We shall see.

Now I’m a huge fan of the ASP.NET MVC framework. So much so that I have taken to porting across applications already started using the Castle Monorail framework. Why? Well, there’s just a nice, warm, supported feeling when using a framework that is built-in to your chosen development platform.

Or at least that’s what you’d think. You know how it is – you get it all working on your lovely development machine and then once the decision has been made on where to host the final result, you upload your application and…bang…

HttpException (0x80004005): The incoming request does not match any route.

Oh yes, that works so well.

Suddenly that belief that, finally, someone has produced a framework which is so nicely integrated with your target platform comes crashing down around your head as you weep softly into your keyboard. No, ASP.NET MVC is not actually supported on anything under IIS7. Does your host offer IIS7 at the moment? I guess not.

Now don’t get me wrong, it does work on IIS6 but you have to mangle it a bit and unless you pay a fortune each month for access to your own virtual server then you’re likely to lose those pretty urls. That’s not the same as being supported. For those that have spent the last two hours Googling and still getting the same problem, here is the man with the answer:

http://haacked.com/archive/2008/11/26/asp.net-mvc-on-iis-6-walkthrough.aspx

You may not have heard of Mark Taplin, but if you watch MTV or VH1 you’ve likely seen his animation work. He also provides illustrations for various modern publications.

http://www.taplabs.com/
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Everyone knows that when you have a text box which accepts a number, it should automatically right-align the text content. Well maybe not everyone, but accountants certainly do and if you’re writing an application for an accountant it just won’t look right unless the values are right-aligned.

Simple, I thought – text-align:right in the CSS and the jobs a good ‘un. Well yes, you would think so. The fact of the matter is that text-align:right is only supposed to apply to block level elements (according to the CSS2 specs), although it isn’t quite implemented that way in all browsers. So, add display:block in there as well just to be on the safe side:

Left Align: <input style=”padding: 0px; text-align: right; display: block” type=”text” />

Right Align: <input style=”padding: 0px; display: block” type=”text” />

Job done! Well, not quite if you are viewing this in Internet Explorer 7. Click in the input field which is aligned to the right and no cursor displays at all! I must be tired today because this took me ages to work out and I found no reference to it anywhere in the web. For some reason the cursor is there – it’s just off to the right a little too far. I say ’some reason’ when I now know that the actual reason is that the padding is set to 0px. The reason for this happens to be because it has inherited the property from other elements in my form layout, but in this example I have added it specifically. Add a little padding to the right and hey presto:

Left Align: <input style=”padding: 0px 1px 0px 0px; text-align: right; display: block” type=”text” />

Right Align: <input style=”padding: 0px 1px 0px 0px; display: block” type=”text” />

That’s just strange. Zero padding displays the cursor on the left, but not the right. Except in Firefox, which just shows it correctly in either case.

An interesting job this one – develop a proof of concept application for vehicle tracking using the Google Maps API. The vehicles in question are already fitted with a GPS positioning system which also provide various other useful bits of information, most notably g-forces. (more…)