project page 2 - Dave's Blog

I keep seeing crowdsource projects with big names that I actually want to back:

• New Ben Folds Five album
• New Double Fine Adventure game
• New Amanda Palmer album
• New Space Quest (like) game

Sarah and I have been enjoying Glitch for a while now. Reviews are usually positive although occasionally biting (but mostly accurate).

I enjoy Glitch as a game of exploration: exploring the game's lands with hidden and secret rooms, and exploring the games skills and game mechanics. The issue with my enjoyment coming from exploration is that after I've explored all streets and learned all skills I've got nothing left to do. But I've found that even after that I can have fun writing client side JavaScript against Glitch's web APIs making tools (I work on the Glitch Helperator) for use in Glitch. And on a semi-regular basis they add new features reviving my interest in the game itself.

As a professional URI aficionado I deal with various levels of ignorance on URI percent-encoding (aka URI encoding, or URL escaping).

Worse than the lame blog comments hating on percent-encoding is the shipping code which can do actual damage. In one very large project I won't name, I've fixed code that decodes all percent-encoded octets in a URI in order to get rid of pesky percents before calling ShellExecute. An unnamed developer with similar intent but clearly much craftier did the same thing in a loop until the string's length stopped changing. As it turns out percent-encoding serves a purpose and can't just be removed arbitrarily.

Percent-encoding exists so that one can represent data in a URI that would otherwise not be allowed or would be interpretted as a delimiter instead of data. For example, the space character (U+0020) is not allowed in a URI and so must be percent-encoded in order to appear in a URI:

1. http://example.com/the%20path/
2. http://example.com/the path/

For an additional example, the question mark delimits the path from the query. If one wanted the question mark to appear as part of the path rather than delimit the path from the query, it must be percent-encoded:

1. http://example.com/foo%3Fbar
2. http://example.com/foo?bar

For my GeolocMock weekend project I intended to use the Bing Maps API to display a map in a WebBrowser control and allow the user to interact with that to select a location to be consumed by my application. Getting my .NET code to talk to the JavaScript in the WebBrowser control was surprisingly easy.

To have .NET execute JavaScript code you can use the InvokeScript method passing the name of the JavaScript function to execute and an object array of parameters to pass:

this.webBrowser2.Document.InvokeScript("onLocationStateChanged",
   new object[] {
      latitudeTextBoxText,
      longitudeTextBoxText,
      altitudeTextBoxText,
      uncertaintyTextBoxText
   });

The other direction, having JavaScript call into .NET is slightly more complicated but still pretty easy as far as language interop goes. The first step is to mark your assembly as ComVisible so that it can interact with JavaScript via COM. VS had already added a ComVisible declaration to my project I just had to change the value to true.

[assembly: ComVisible(true)]

Next set ObjectForScripting attribute to the object you want to expose to JavaScript.

this.webBrowser2.ObjectForScripting = this.locationState;

Now that object is exposed as window.external in JavaScript and you can call methods on it.

window.external.Set(lat, long, alt, gUncert);

However you don't seem to be able to test for the existence of methods off of it. For example the following JavaScript generates an exception for me even though I have a Set method:

if (window.external && window.external.Set) {

I've made GeolocMock. If your PC has no geolocation devices, IE9 uses a webservice to determine your location. GeolocMock uses FiddlerCore to intercept the response from the webservice and allows the user to replace the location in the response with another. This was a fun weekend project in order to play with FiddlerCore, the W3C Geoloc APIs in IE9, hosting the IE9 WebOC in a .NET app, and the Bing Maps APIs.

• Jaydiohead - Radiohead & Jay-Z mashup. Listen:
  Jaydiohead - 06 - Dirt Off Your Android by Max Tannone


• Selene - Richard Rich & beats over the Moon soundtrack. Listen:
  Selene - 01 - You Are Here by Max Tannone


• Double Check Your Head - Beastie Boys albums mixed together. Listen:
  Beastie Boys - 02 - Pass The Gratitude by Max Tannone
  

For a new project I'm working on involving IE's installed Accelerators and OpenSearch search providers via the Windows 7 Accelerator Platform, I've created a C#/COM interop class for those APIs.

Download the osinterop.cs interop file here.