Tuesday, 26 June 2007

Closing Tag Identifier

I often see HTML comments used to relate a closing tag to its opening tag; when a DIV or some other container tag contains enough content to make viewing the entire block without scrolling impossible, I think this makes perfect sense.

For example:

<div id="myTag">
</div> <!-- end myTag -->


This is also sometimes helpful with C-like languages that use braces to delimit blocks of code.

Although modern development tools highlight closing tags and braces, HTML code in particular isn't always read within one of these tools (View-->Source in IE opens the source code in Notepad, for instance).

To assist, I think it would be helpful to have the option of attributing a closing tag with the same id used by the opening tag:

<div id="myTag">
</div id="myTag">


Our fancy editors would keep the opening/closing ids in sync and browsers could safely ignore the additional attribute.

In practice, this works quite nicely with the caveat that a page built like this is invalid.

Monday, 25 June 2007

My "Cubicle" Rocks!!!

I recently reconfigured things at work...

Thursday, 21 June 2007

Must-Have Web Development Tools

ASP.NET Fragment Caching in MOSS

I've noticed an odd happening with fragment caching in MOSS 2007: a user control declared in a master page will not be cached but when that same user control is wrapped in a second user control and the wrapper control is declared in the master page, the wrapped control caches as expected.

Things look like this:

Masterpage:

<%@ Register tagprefix="CustomControls" tagName="Container" src="~/UserControls/Container.ascx" %>
<%@ Register TagPrefix="CustomControls" TagName="ToCache" Src="~/UserControls/ToCache.ascx" %>
<CustomControls:Container id="container" runat="server"/>
<CustomControls:ToCache ID="toCache" runat="server"/>

Container.ascx:

<%@ Register tagprefix="CustomControls" tagName="ToCache" src="~/UserControls/ToCache.ascx" %>
<CustomControls:ToCache id="toCache" runat="server" />

The resulting HTML looks like this:

<body>
<div id=”container”>
<div id=”toCache”>... </div> // This caches
</div>
<div id=”toCache”>... </div> // This won’t cache
</body>

The ToCache.ascx user control sets a simple @OutputCache directive in the markup and I can't see anything that would limit output caching in the master page, the hosting .aspx page, or the web.config.

I haven't ripped this apart and tried it in a clean site but I'm definitely experiencing this behaviour within the context of the wa.com development environment. I know MOSS controls (and somehow enhances) output caching but I have yet to look into how this works--as far as I know, I'm using the default output caching configuration.

Update: I wonder if this has anything to do with the control being hosted in a master page instead of an aspx page layout. Slim chance...

Disabling the "Reply to All" email button

Gotta love it when the CEO sets the technology direction in your office... (the identities of those involved in this memo have been obscured but this is a genuine email). Guess that's the final nail in the coffin for Outlook on my desktop.

Surely there's a Dilbert strip for this?

From: xxx
Sent: Thursday, 21 June 2007 10:25 AM
To: All Staff
Subject: Disabling the "Reply to All" email button

The CEO has requested that Corporate IT disable the “Reply to All” button for all staff in order to assist with email and time management.

We will trial this for a few weeks and then I will seek feedback on how effective this has been and request executive directors to bring the feedback to the executive management team for discussion.

The process will happen progressively over the next few days.

Thanks


xxx
Executive Director



Wednesday, 20 June 2007

Units of Time

One thousandth of a second = 1 millisecond (ms)
One millionth of a second = 1 microsecond (┬Ás)
One billionths of a second = 1 nanosecond (ns)

See http://www.wilsonmar.com/1clocks.htm for great discussion about time in a networked world.

Monday, 18 June 2007

Visual Studio 2005 Debugger Won't Break

Ever encounter a situation where the Visual Studio 2005 debugger absolutely refuses to break? I ran up against this problem this afternoon (yet again) and it took me a moment to discover the reason why.

Here's the scenario:
  • A standard user control with a code-behind file is hosted in an insignificant ASPX page;
  • The user control code-behind is doing some work to render the control and also has a handler method subscribing to a button click event;
  • The relevant assemblies are built in debug mode and are deployed to a separate development server along with the associated markup files;
  • The assemblies on the server are the same version as those on the development workstation;
  • The application is configured as it should be in IIS and the debug attribute on the web.config's compilation element is set true;
  • The VS 2005 remote debugger is installed and running on the dev server;
  • The VS 2005 "client" is attached to the remote server's ASP.NET worker process (w3wp.exe in this case);
  • Two breakpoints are set on the user control code: one on Page_Load and one on the button click handler;
  • Browsing to the host page doesn't cause the debugger to break (except intermittently, sometimes following an iisreset)...
Inspecting the two breakpoints reveals nothing out of the ordinary; symbols are loaded and the debugger is breaking every so often, just for kicks. The code itself is executing happily, it seems.

Here's the problem:

The user control in question had an OutputCache directive set to cache the control for sixty minutes. Removing this little devil resulted in a slap of the forehead and allowed the debugger to break as expected.

The OutputCache directive prevents the control being added to the control tree of the hosting page at runtime; ASP.NET loads an existing version from the cache instead of executing the control code.

...kind of a silly problem since the debugger gives you no inidication the control is loading from the cache but it's all too easy to forget about this sort of thing!!! The golden rule I usually try to apply is to hold off on performance tuning until the very end of the development/testing process and this should generally include large-scale caching. Obviously this doesn't apply in a maintenance situation.

[Update: a few additional tips...
  • Double-check the deploy location of your assembly; if it's in the GAC you can deploy to the bin directory until the cows come home but ASP.NET will continually load the assembly from the GAC. Either remove the GAC'd assembly or deploy to the GAC (you can also deploy PDB files to the GAC but you need to drop them under gac_msil using the command line).
  • Once you've attached the debugger, bring up the Modules window (Debug -> Windows -> Modules); locate your assembly and verify whether symbols have been loaded and the location where the assembly was loaded.]

Monday, 11 June 2007

Friday, 1 June 2007

Everything you always wanted to know about Javascript but were too afraid to ask

I’ve been hacking with Javascript since ’97 or so and it always seemed so accessible I never thought about sitting down to actually discover what it’s all about. Between AJAX and widgets and funky calendar controls I've recently came across constructs I'd never seen before—admittedly Javascript is, even after nearly x years, a mystery to me. Or rather it was, until I read this article:

http://odetocode.com/Articles/473.aspx

The article is reasonably short, very concise and explains a lot about the language itself. Better still, the article is targeted at .NET C# developers who know more about classes and method than prototypes. The examples are great as well.

Looks like Javascript isn’t going away any time soon so I’d suggest this article as a great intro to the rest of your life as a Javascript developer ;-)