24/7/dev&coffee : Programming

Dissecting a web application - part I - requirements and plans

michu — Thu, 28 Apr 2005 21:23:00 GMT

With this entry I am starting a series of articles describing the process of creation of complete web application with additional tools, http://theexpedition.info. This article is available also in Polish language on my other weblog.

In my previous entry I announced the launch of website about my planned expedition around the globe. As you can easily see, the http://theexpedition.info website uses ASP.NET, what you can't see but probably can guess, there is also a MS SQL Server database involved. Big thanks to my friend from Xenium for providing me with a free hosting.

My choice of technology was pretty obvious, as I am a .NET developer, probably more interesting are the requirements I had for the web application. These requirements weren't exactly typical, so I decided to create my own app. In this article I will try to describe main properties of the application that I wrote (and am still writing, as there are some more things to do).

First: The website should have structure of a weblog. Published entries should be displayed in reverse-chronological order, 10 on the main page of website, all other in the archive, in the form of headlines linked to full content.

Second: Besides blog-style entries, there should be a way to publish longer entries - articles. These articles can have aliases (for example "car" will be the alias of article descibing my (not existing yet) vehicle). I decided to identyfy entries by GUIDs (more on that later) and aliases will make creating URLs easier - they will act as shortcuts to chosen articles.

Third: Blog entires can be commented. It is nothing extraordinary, I just have to ensure that it is SQL-injection and Script-injection safe.

Fourth: There should be a RSS feed for convenient reading thru news aggregator.

OK, these were the typical things. Probably I should use Community Server and get all (or almost all) of that functionality for free. Why did I choose a custom solution? These are the reasons:

First: Website should be two-language. I want to promote it both in Poland and abroad (hoping a bit to create a buzz and interest some potential sponsors), so it was necessary that both UI and content were affected by choosing the language (EN/PL). What is more, I wanted to create a language autodetection mechanism based on HTTP headers sent by browser and preference-storing mechanism, remembering user choice (that can be different than autodetected setting) for following visits.

Second: Besides standard elements of blog / informational website, TheExpedition.info should contain structured data about visited places and GPS coordinates related to each entry or photo.

Third and the most important: I want to update the website straight from the field, using the laptop computer and different kinds of internet connection. Sometimes I will be able to go to internet caffee, sometimes I would be using a GPRS connection, and sometimes - if my budget allows (Sponsors, do you hear that? ;-) - a satellite uplink (slow and expensive). I need to be able to publish all elements desribed above without struggling with web administrative interface and with least possible bandwith use. So there goes...

Fourth: Together with web application I have to create a desktop client application, allowing me to prepare content (entries, articles, photos, places and coordinates metadata) and send it compressed to web server thru FTP. There it should be automaticaly uncompressed and used to update a website. Additionally, there goes...

Fifth: Because I will need to use expensive and slow connections, the client application should allow publishing: texts alone, texts with image thumbnails, texts with thumbnails and full-resolution photos, only pending thumbnails (these already prepared but chosen to be not published until better connection conditions) or pending thumbnail together with hi-res photos.

Sixth: In my LandRover I will have a webcam installed. It will be making a photo of the road in front of the car every 5 minutes. It gives about 144 photos a day (assuming a 12-hour drive). This probably won't be published on the website during my expedition, but after I come back home. It will be a treat: full travel around the world using a slideshow of 50-100 thousands of photos. Would you consider buying a CD with such thing? Or downloading the CD image? Let me know, I want to know the possibilities. My client application should store these photos and annotate them with coordinates.

Seventh: Web application should gather basic statistics about page views and refferals, but without abusing the server I can use for free.

And that should be all. In next weeks I will walk through all modules of my web and client applications, describing their design and implementation using ASP.NET, Windows Forms, C#, XML and MS SQL Server. Do not hesistate to add a RSS of my weblog to your news aggregator and do the same with a feed from TheExpedition.info! I have planned a lot of interesting content. Spread news! Now I need all the publicity I can get, because soon I will start looking for sponsors. Thanks!

From the lists department... Open source applications in C#

michu — Mon, 07 Mar 2005 20:55:00 GMT

That is a nice site: http://csharp-source.net/

But where is a RSS feed?

A bit of self-boasting ;)

michu — Tue, 23 Nov 2004 14:56:00 GMT

I just received an email... I have got a second place in .NET Master (in Polish Mistrz.NET) competition held by Microsoft Poland. Wow! :) Thanks to all friends who wished me luck!

Injection attacks - spread it around!

michu — Thu, 19 Aug 2004 07:43:00 GMT

It's very disturbing how few web application developers know anything about injection attacks. Like Bertrand LeRoy noticed, web forums are full of questions accompanied with code showing that the person who wrote it was completly clueless in that matter. So here comes Bertrand's article explaining those problems. It's very well written and should be easy to understand for everybody who knows anything about web applications and web programming.

Spread it around and make web a safer place!

Why is IE going down so much?

michu — Fri, 09 Jul 2004 11:38:00 GMT

Having enough of problems with IE, I'm switching to Mozilla Firefox today.

Why?

First, there are all those security problems. Last update to ADODB.Stream seems to be only a quick-fix for particular problem and it isn't even trying to address many other, *known* issues with ActiveX security - for example with much-discussed Shell.Application component (more info here). There is even example exploit ready - opening harmless command prompt, but it is only a matter of time, when somebody find some more “practical” use of that technique. On abovementioned site you can find also an instruction how to patch registry to disable this component, just in case.

Second, features. IE was for some time beautiful in its simplicity. Now it looks only outdated. Popup filters and download manager? A praised features of upcoming version, while other browser have it for ages. Tabbed browsing? Nope. Mouse gestures? No way. Zoom? Are you kidding? Extensible support for search engines? No way, and probably it will never be included because MSN tries to build on search now. Etc.

Third, web standards. Yeah, I know it is vague. But just try to make XHTML+CSS complaint site, which will look the same in all browsers. IE always goes in the way. Just look what it means: IE, which was always feature-rich for developers, now is the most annoying browser for the same people. Statistics show that IE is losing users, but the loss of developers is the crack that will be most difficult to fill.

To summarize: IE guys, you have to get out of year 1999 as soon as possible. When people say Microsoft, they think Windows and IE. This is the most common. Losing IE for Mozilla or Opera you are giving away a lot more than some small percent of users - you're giving away a lot of brand recognition. How can anybody forget about the first and most used application of his clients? Is this arrogant or just overlooking? How can you say you want to provide the very best experience to users when the most important tool, an icon of our times, browser which is the very first computing experience of many people, is so broken?

So, make me come back to IE. Or maybe nobody cares?

071-340 beta exam - strange results

michu — Tue, 06 Jul 2004 01:27:00 GMT

I just received my score report for 071-340 beta exam (Implementing Security for Applications with Microsoft Visual C# .NET) I took on April, 21st. It was the first time I was participating in beta exam program. It was interesting experience, but waiting for results for 2.5 month is long. I wanted to prepare for that exam, but I couldn't find any time to do it - it was very stressful and crazy time in my life, so studying for beta exams wasn't a priority. I went to the exam without a minute of preparation and came home sure that I failed it. But, to my surprise, I passed.

What is very strange (or maybe not, looking at my preparation technique ;-) ), the comments under each of exam sections say that I need to develop that skill:

It is so even if I scored “strong” in that particular field. Is this a bug, or maybe 100% strong is normalized to my highest score of all subjects, or maybe they put that “Needs Development” label always, to encourage people to develop their skills constantly? ;-)

Does anybody know?

Anyway, I'm very happy that I passed. It was a very pleasant surprise.

UPDATE: In fact, I'm using this stuff daily. So there probably was a bit of preparation, maybe only not so formal :-]

UPDATE 2: Oh,my! This is how it goes when one sorts his mail at 3 AM. As some people said in comments, it is a label - opposite to “Strong”. Now I see it and I'm embarassed :-/

Is that new or I missed it all the time?

michu — Fri, 02 Jul 2004 23:10:00 GMT

I just installed .NET Framework 2.0 and some Express Tools and I noticed something (maybe) new.

When I open IIS Manager, right-click my website and click properties I have a new tab:

Then there I have a GUI tool for editing of my Machine.config and Web config - it looks interesting:

Or was it there all the time? Quick check... nope, on my .NET 1.1 machine there is no such tab.

So, I have something new&cool to play with :-)

UPDATE: So, this is definitely new :-) I'm used to manualy edyting web.config and machine.config, but it is anyway a great tool. Increases discoverability of .config features a lot. Best way to start playing with those files in .NET 2.0 and see what's new.

My contribution to The Daily WTF

michu — Sat, 26 Jun 2004 17:24:00 GMT

My entry just got published on The Daily WTF. That's cool :)

Generating Excel files from web - line breaks in cells

michu — Tue, 15 Jun 2004 08:32:00 GMT

As many of you probably know, you can output data (a report, for example) as an Excel file, simply by adding right content-type and content-disposition header:

Response.ContentType = “application/vnd.ms-excel“;
Response.AppendHeader(“content-disposition“, “inline; filename=report.xls“);

If client has MS Excel installed, your output HTML page will be opened in it instead of web browser. Excel will interpret all formating (borders, fonts etc.) and TABLE tags, which can result a nice, formated worksheet, without using heavyweight server-side controls.

The problem I was struggling for some time was with multi-line cells. I needed to wrap text in cell, but when I put <br> tag into HTML output, Excel interpreted it as a new row, not a line-break in existing cell.

The solution I found is to add into a stylesheet:

    br {mso-data-placement:same-cell;}

Then it works like a charm. I hope somebody will find it useful :)

Tip: You can make ContentType and header conditional, providing alternate HTML/XLS reports with one file.

Telecommuting is all wrong or is it something with me?

michu — Mon, 14 Jun 2004 09:45:00 GMT

For last three years I was working as a programmer from home, using Internet, VPNs, Terminal Services etc. to connect to my company's network. I find it a very unpleasant experience. My employer wasn't a software vendor, it was a retail company, I was working on internal projects - intranet site, website, sales software, CRM etc - and for last year I was lent to work on intranet & workflow projects for one of my employer's clients, who has seen and liked what I did before. But for me it was a very hard time.

One problem is that we live 4 person in a small 2-room flat. It means that my workplace was in my bedroom and our small children were everywhere. Second, because I was a developer in a no-development shop, I was the only person who know anything about software development. It generated all wrong practices that are possible, for example introducing new features during development, lack of documentation, unrealistic schedules (wonder if somebody consulted them with me? no way!) etc. There was no chance to explain those things to management and make it proper. And of course it damaged all schedules, as you probably know.

But what was really bad, was the way that my work started to slip into my life and 'overwrite' it. I was working more and more, catched in mutual feedback between growing expectations of my employer and my own efforts to do everything I had to do on time, struggling with what I described in above paragraph. At first, I was working 8 hours a day. Then, there was an urgent project and I increased that time to 10 hours (telling myself it was only temporarily), then to 12... For last year or so I was working about 16 hours a day, including saturdays. It was a nightmare. Then I quit.

I wonder if it is a fault inherent to this way of working, a fault of my employer or myself? In any given short period of time I didn't feel that I was working more. It was a lot of small steps - “I'll work an hour more to finish this”, “Michal, could you do it on Monday? It is very important” etc. I was giving away a bit of my life more every week. Why I let it happen? I don't exactly know. One thing is that I'm passionate for what I do. Second - it was a quite good payd job, what is hard to find at this moment in Poland. Third - working at home I felt a kind of ilusion of freedom, for a long time I haven't noticed that I just switched a harness of office-work for the one in my mind.

Two weeks ago I started a normal, regular, 40-hours-a-week job in office, in a big software company. And I already love it. I finally have time for my daughters and wife, time to read something, time to do many things I haven't done for a very long time. Time to work on my little project which I probably announce soon ;-) (and the money are better, too)

If you worked from home or considered it, please share your experiences. I'd like to see if somebody went through something similar, or maybe it works for other people?