I just stumbled over a funny little thing in the HTML output from the Html.CheckBox() helper method in ASP.NET MVC 1.0.

In my .ASPX file, I had defined a checkbox like this

<%=Html.CheckBox("MyCheckBox") %>

 
This resulted in the following HTML output:

<input id="MyCheckBox" name="MyCheckBox" type="checkbox" value="true" /><input name="MyCheckBox" type="hidden" value="false" /> 

A bit stumped as to why I got an extra hidden field, I decided to have a look in the ASP.NET MVC source code and found the following comment:

if (inputType == InputType.CheckBox) {
    // Render an additional <input type="hidden".../> for checkboxes. This
    // addresses scenarios where unchecked checkboxes are not sent in the request.
    // Sending a hidden input makes it possible to know that the checkbox was present
    // on the page when the request was submitted.
...

This is really quite logical. The reason it works is that the first time a browser hits an element with a value attribute, the parser will ignore all subsequent elements with the same name. This way, we’ll always get a result back to our controller containing all the checkboxes that are present on the page, no matter if they are checked or not.

A little over a year ago, I got my Scrum Master certification. The two day certification was extremely encouraging and inspiring, and I really felt I was ready to take on the world with my newly-acquired skills. And Certified Scrum Master sure does sound sexy, doesn’t it?

One of the things I like the most about the Scrum Master role is the coaching aspect. I really enjoy coaching, and I love the satisfaction I feel inside as the process begins to grow on the development team. When they start gathering at one-minute-to-daily-scrum-time so they can report the day’s progress to each other.

But why is Scrum so hard to get to work properly?

At the company I work, I have been trying hard for a year now to implement, if not all, then some of the Scrum process into our daily workflow. And my boss has been backing me as best as he can. My main problem is that he (and basically everyone else in the organization) don’t really understand Scrum. Some know of the basics (daily standup “scrums”, sprints, timeboxing, burn down charts), but I’m learning the hard way that if Scrum is to be successful in our department, everyone around us needs to somehow be aligned to the process and work model. Basically, I think that sending everyone to get Scrum Master certified would definitely help. But of course this isn’t really an option.

One of our biggest impediments is that we don’t have real product owners. This role is basically missing, and we “get by” at every sprint start by asking someone in the organization with domain knowledge to play the role of product owner. We also face the challenge that many of our projects are either complete re-writes of older products, or they’re something new altogether. They aren’t simply existing products that we’re just adding features to. This means that the scrum teams are facing a huge amount of architectural decisions during sprints. And seeing as we don’t really have an “architecture team”, many decisions are just made at meetings they hold together. These meetings are expensive – they often come up completely unplanned and can easily throw the burn down chart way off (I’ve seen it happen many times).

Another impediment is that we’re in the process of integrating systems from a competitor that we acquired earlier this year. This is of course a top-priority from the management group and they will spare no means to get the job done. In practice this has the effect that team members can get pulled at moments notice to do something else. And there is little I can do to stop that.

Another challenge I’m facing is the whole aspect of reporting. Finance would like us to begin reporting hours spent on each and every development project. The problem is that “time spent” is not measured in Scrum. At least not if you want to follow the process completely (which is a goal for me – Ken Schwaber, the father of Scrum, says “If you are not an expert in something, you are not at liberty to change it” – and I totally agree) I cannot possibly adapt Scrum to “work better for us” if I haven’t fully tried it in its basic form first. And we’re still getting there. But nonetheless I still have to figure out an effective way of reporting hours from the team, without asking them to actually start logging work done.

The next thing I’m going to try to push into the team is the concept of using story points when planning the product backlog. I want to start pushing the concept of relative size of backlog items, as opposed to using hours or man-days. The reason I like the idea of story points is that managers have a tendency to accept hour or day estimates as a commitment from the team. By using story points we abstract this away and convey the fact that backlog estimates are extremely rough and are solely based on hunches (because of the nature of backlog items, in that they are not at all very specific).

Next week I’ll be attending the ÖreDev conference in Malmö, Sweden. I’ll be following quite a few Agile sessions and hope to get some answers to some of my questions. Like “How can we get better at following the Scrum process as a company and not just as a small isolated team”

I promised to follow up on my adventures in using shared storage for hosting data being served by a cluster of blades. Unfortunately we don’t (yet) have a nice SAN or anything like that, so all I had access to was a simple Windows file share on a NAS (I love three letter acronyms!). I couldn’t get over the concurrence problems I faced, and servers were constantly tripping over each other giving me file locking errors and stuff like that.

So I ended up spending a day writing a small deployment application that could copy the code out to all the blade servers. What my tool does is this:

 

1. Copy an App_Offline.htm file to the root of all web servers. The App_Offline file shows a message to users that we are upgrading and that we’ll be right back.
2. Copy latest build from the build server to each blade
3. Modify web.config to disable debug, fix connection strings etc
4. Remove App_Offline from all blades.

 

All in all this ends up working really well and is easy to work with. Also, it allows me to easily hand over the deployment task to someone else, as this person only needs to install the small click-once deployment tool.

 

In a few hours I'll be flying to Vienna before heading on to Postojna (Slovenia), Venice, Trieste and ultimately, Amsterdam where I will be taking part in Sensation White. I haven't been blogging much at all lately. Things have been really hectic at work so I haven't really been able to find the time.

I've started working on a new version of my free SubVersion hosting system. The frontend will be done using the new ASP.NET MVC Framework and I hope to get the backend a bit more "enterprise-like" - probably by using message queueing and/or WCF to pass notices between the frontend and backend. We'll see. I haven't decided 100% yet.

Oh - and yesterday I decided to start using Twitter much more actively. I already have a couple of followers but feel free to add me. I've installed Twibble on my N95 8GB, so everywhere I have Internet access I should be able to update.

Wow! Finally! By chance I stumbled across another blog post on the web, where a solution (or temporary fix until something better turns up) to my ongoing PageRequestManagerParserErrorException problems.

Basically the problem is that on a page where I use the Microsoft AJAX.NET framework, I get intermittent popups when viewing the pages in Firefox. The popups contain the nice, short, concise error message "Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed. Common causes for this error are when the response is modified by calls to Response.Write, response filters, HttpModules or server trace is enabled. Details: Error parsing near ''"

Now I finally found someone who came up with a simple yet effective hack to mask/solve the problem. The solution involves adding some Javascript to your pages and then overriding the OnInitCompleted method on the server side.
Here's the JavaScript code:

<script type="text/javascript" language="javascript">
window.isFireFox = (navigator.userAgent.indexOf("Firefox") != -1);


if(window.isFireFox)
{
        window.addEventListener('load',OnPageLoad,false);
        function OnPageLoad()
        {
                 Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(OnBeginRequest);       
        }

        function OnBeginRequest(sender, args)
        {
                var delta = args.get_request().get_headers()['X-MicrosoftAjax'];    
                if(delta == 'Delta=true')    
                {
                    var body = args.get_request().get_body() + 'X-MicrosoftAjax=' + encodeURIComponent('Delta=true');        
               args.get_request().set_body(body);    
                }
         }
}
</script>

And here's what goes in your codebehind:

protected override void OnInitComplete(EventArgs e)
{
  #region Firefox Fix

  ScriptManager sm = ScriptManager.GetCurrent(this);
  if (IsPostBack && Request.Browser.Browser == "Firefox" &&
   sm != null &&
   sm.IsInAsyncPostBack == false &&
   Request.Form["X-MicrosoftAjax"] == "Delta=true")
  {
    sm.GetType().GetField("_isInAsyncPostBack",
      System.Reflection.BindingFlags.NonPublic |
      System.Reflection.BindingFlags.Instance).SetValue(sm, true);
  }
  #endregion
  base.OnInitComplete(e);
}

Lo, and behold, it seems to work! Thanks to M. Bhaskar for the solution!

I stumbled across this on the web somewhere. I think it shows pretty well what some of us spend most of our time doing.

So true, so true...

After installing VS2008 last week, I noticed that my IntelliSense wasn't working. This is something really annoying to a person who has always relied heavily on IntelliSense while coding.

I searched the web a bit and came across this blog entry. This solution worked perfectly for me. Here's a quick walkthrough.

1. Hit Tools / Options in your Visual Studio.
2. On The Left Tree click Text Editor / All Languages.
3. Under Statement completion ensure that “Auto list members” is checked with a tick mark. (Make sure that this option is fully selected and not partly selected)
4. Under Statement completion ensure that “Parameter information” is also checked with a tick mark. (Make sure that this option is fully selected and not partly selected)

Nice and simple :-)

Wow! I really need to get better at updating my blog with interesting little articles about this and that. Here's one example that I've been working with over the past two weeks.

A short background
The company I work for, Infopaq International, is a media watch company and delivers news clippings to customers in one of several formats. One possibility is (in the countries that allow this because of copyright legislation) to provide E-clippings in a PDF file.

And then...
Until now, this PDF file has been really simple with nothing but our logo at the top and the clipping centered on the page. I was asked to look into how we could beautify these e-clippings so they would be more aesthetically pleasing and also contain more information. For example, information about the customer, the media from which the clip came, etc. My colleague in Stockholm sent me a mock-up of how he would like the final PDF to look, and I set about figuring out how to get the job done.

The old solution was built using iTextSharp so i decided to have a closer look at what functionality was available in this library. I set off to try to programmatically build a PDF file the way my Swedish colleague wanted but soon discovered that this really wasn't as easy as I first had hoped. At least I found it to be quite challenging to get things to align just the way I wanted them to.

So I put my thinking cap back on and started to ponder what else could be done. After a bit of reading, a bit of Googleing and a lot of staring at iTextSharp, I decided to go for a different approach. I installed Adobe Acrobat and set off to design my PDF using a real PDF authoring utility. I thought (wrongly, by the way) that I could simply define some fixed strings in the template which I then could search-and-replace with data from my database. It turned out that PDF just doesn't support that possibility. But then it struck me. I remembered reading somewhere about filling out PDF forms from iTextSharp. I Googled a bit and decided to give it a try.

I designed a PDF form using Adobe LiveCycle Designer and assigned meaningful names to all the fields (there are about 30 fields in total on the form). Now it was only a question of using iTextSharp to fill out the fields and then spit out the finished result to the client. And now for some code:

// Open the template PDF file
PdfReader rdr = new PdfReader(HttpContext.Current.Server.MapPath("~/App_Data/Template.pdf"));
// _outStream is a HTTP Response Stream
PdfStamper stamper = new PdfStamper(rdr, _outStream);
// Grab our fields
AcroFields fields = stamper.AcroFields;

// And then a whole load of these (in this case reading the department name from XML):
fields.SetField("InfopaqCompanyName", departmentNode.SelectSingleNode("departmentname").InnerText);
(...)

(...)
// Close our stamper
stamper.FormFlattening = true;
stamper.FreeTextFlattening = true;
stamper.Close();

And that's just about all there is to it :)

For the past couple of weeks, I've been fighting with a really strange error when using UpdatePanels on my websites. It seems that if a page stands idle for too long ("too long" is variable - sometimes it's a few seconds, other times it's minutes), I get a JavaScript popup with a PageRequestManagerParserErrorException message. Apparently the error only appears in FireFox!

The error message states something about it being caused by Response.Write(), HTTPHandlers or any other things that might change the output stream, thereby corrupting the AJAX request. I searched through my code and couldn't find any of the mentioned causes.

Now this morning, I decided to do a simple test. I've created an aspx page containing an UpdatePanel, a Timer and a Label. On the tick event of the timer, I just update the label with the current date and time. Simple and a "schoolbook" example of what AJAX can do.

When I run the page, the label starts updating. Now if I wait for long enough (again, variable), I get the exact same error message. So it turns out that it has nothing to do with page complexity, several UpdatePanels or anything like that. It's a general error.

After searching the web for likely solutions (or causes, so I could find my own solution), I've pretty much given up. Does anyone know what might be causing this error? I've attached my simple website so you can see what I've done. ANY feedback is greatly appreciated!

AJAXEnabledWebSite.zip (2.36 KB)

Another little thing that I stumbled across - when trying to hide a control from anonymous users, I just tried the following:

Visible='<%#Page.User.Identity.IsAuthenticated %>'

Now I would have expected that to just work. But when I viewed my page, the controls were still visible. After a bit of trial and error it occurred to me that the <%# syntax is used when databinding. So in my Page_Load method, I just called myControl.DataBind(); and everything worked perfectly.