Windows LiveWindows Live™
 
 
William's profileBill PierceBlogLists Tools Help

Blog
    6/29/2006

    Google Checkout

    If everyone isn't blogging about it yet, they will be.  Google launched Google Checkout. 
     
    At first glance, here's what I like about it:
    • I only need to remember one username/password to see all my purchases from participating merchants
    • I only store my Credit Card information with one system
    • I can shop in a nearly anonymous fashion.  Google will proxy your email address and credit card number
    • I can forsee a lot of integration with other Google provided services (shippment tracking via Google Maps, email notification, RSS notification to your Google homepage, IM notifcation via Google Talk

    Everyone thinks that Microsoft is the big evil empire but I think because they live with that image they work doubly hard to prove that isn't the case.  I am actually more leary (sp?) of Google and their access to massive amounts of data, now including my purchases and credit card information.

    Thoughts from the peanut gallery?

    8:31 AM | Add a comment | Permalink | View trackbacks (2) | Blog it
    6/21/2006

    Switch Hitting

    My right wrist was giving me grief the last few days.  My finger joints are also feeling a bit stiff.  The obvious answer is to not spend 10-12 hours a day on the computer.  My job and hobbies make that difficult.  So, I used the mouse with my left hand all day yesterday.  It wasn't as bad as I thought.  The most difficult task was dragging windows around on my dual monitor setup.  I also reversed the mouse buttons and increased the mouse speed to help compensate.  I don't think I'll be playing Counter Strike with my left hand anytime soon, but its good to know I can ruin both hands with carpel tunnel.
    7:11 AM | Add a comment | Permalink | View trackbacks (2) | Blog it
    6/14/2006

    Javascript Keystroke Handling

    Here is a script I hacked together to capture keystrokes.  Should be cross browser.  Can also intercept browser buttons (like PageDown/PageUp).
     
    function addListener(a,b,c,d){if(a.addEventListener){a.addEventListener(b,c,d);return true;}else if(a.attachEvent){var e=a.attachEvent("on"+b,c);return e;}else{alert("Handler could not be attached");}}

    function bind(a,b,c,d){return window.addListener(a,b,function(){d.apply(c,arguments)});}
    function handleKeystroke(evt)
    {             
    // Grab the cross browser event
    if( !evt ) evt = window.event;
    // Character code of key pressed
    var asc = !evt.keyCode ? (!evt.which ? evt.charCode : evt.which) : evt.keyCode;
    // ASCII character of above code
    var chr = String.fromCharCode(asc).toLowerCase();
    for (var i in this)
    {
      if (asc == i)
      {
     this[i](evt);
     break;
      }
    }
    }
    function cancelEvent(evt)
    {
    evt.cancelBubble = true;
    evt.returnValue = false;
    if (evt.preventDefault) evt.preventDefault();
    if (evt.stopPropagation) evt.stopPropagation();
    return false;
    }
    //
    // KEY COMMANDS
    var keyMap = new Array();
    var PAGE_DOWN  = 34;
    var PAGE_UP    = 33
    var ARROW_DOWN = 40
    var ARROW_UP   = 38
    keyMap[PAGE_DOWN] = pageDown;
    keyMap[ARROW_DOWN] = pageDown;
    keyMap[PAGE_UP] = pageUp;
    keyMap[ARROW_UP] = pageUp;
    //
    function pageDown(evt)
    {
    alert("You clicked DOWN and we are going down");
    }
    function pageUp(evt)
    {
    alert("You clicked UP but I am canceling that request");
    cancelEvent(evt);
    }
    // Add the keydown listner to the document object for global capture
    bind(document, 'keydown', keyMap, handleKeystroke);
    1:17 PM | Add a comment | Read comments (2) | Permalink | View trackbacks (2) | Blog it
    6/12/2006

    IE-FF String Manipulation

    I was porting Stephen Toub's excellent Levenshtein Edit Distance algorithim to Javascript.  The original implementation is shown below (I apologize for my short-hand hacker shortcuts):
     
    function LevenshteinDistance(x, y)
    {
      var n = (x.length || 0);
      var m = (y.length || 0);
     
      if( n == 0 ) return m;
      if( m == 0 ) return n;
     
      var curRow = 0, nextRow = 1;
      var rows = new Array(new Array(m+1), new Array(m+1));
      for( var j=0; j<=m; rows[curRow][j]=j++);
     
      for( var i=1; i<=n; i++ )
      {
        rows[nextRow][0] = i;
        for( var j=1; j<=m; j++ )
        {
          var d1 = rows[curRow][j] + 1;
          var d2 = rows[nextRow][j-1] + 1;
          var d3 = rows[curRow][j-1] + ((x[i-1] == y[j-1]) ? 0 : 1);
          rows[nextRow][j] = Math.min(d1, Math.min(d2, d3));
        }
       
        if( curRow == 0 )
        {
          curRow = 1;
          nextRow = 0;
        }
        else
        {
          curRow = 0;
          nextRow = 1;
        }
      }
     
      return rows[curRow][m];
    }
     
    Running the code appeard to work fine with my test cases in FireFox.  So, I ran tests in IE and was getting different results.  There were no errors, no exceptions, just a different distance value returned.  I banged my head for 20 minutes trying to figure it out. 
     
    Finally a coworker was walking through the code, alerting some debug info, and we came accross the problem. It appears that IE does not support array syntax when accessing characters in a String:
     
          var d3 = rows[curRow][j-1] + ((x[i-1] == y[j-1]) ? 0 : 1);
     
    The output of x[i-1] and y[j-1] was always 'undefined' in IE.  The final version below uses charAt():
     
    function LevenshteinDistance(x, y)
    {
      var n = (x.length || 0);
      var m = (y.length || 0);
     
      if( n == 0 ) return m;
      if( m == 0 ) return n;
     
      var curRow = 0, nextRow = 1;
      var rows = new Array(new Array(m+1), new Array(m+1));
      for( var j=0; j<=m; rows[curRow][j]=j++);
     
      for( var i=1; i<=n; i++ )
      {
        rows[nextRow][0] = i;
        for( var j=1; j<=m; j++ )
        {
          var d1 = rows[curRow][j] + 1;
          var d2 = rows[nextRow][j-1] + 1;
          var d3 = rows[curRow][j-1] + ((x.charAt(i-1) == y.charAt(j-1)) ? 0 : 1);
          rows[nextRow][j] = Math.min(d1, Math.min(d2, d3));
        }
       
        if( curRow == 0 )
        {
          curRow = 1;
          nextRow = 0;
        }
        else
        {
          curRow = 0;
          nextRow = 1;
        }
      }
     
      return rows[curRow][m];
    }
     
    File this one under GOTCHAS
    10:39 AM | Add a comment | Read comments (1) | Permalink | Blog it
    6/5/2006

    Quoteables

    Oren Eini (aka Ayende) maintains an excellent blog on .Net programming focusing on IoC, DI, nHibernate, TDD, and good design in general.  Reading his blog has helped me become a better programmer.  If you aren't a regular listener, I highly recommend his site.
     
    For other great blogs, checkout my Blogroll.
     
    Anyway, Oren provided an excellent quote on his blog today that made me and my co-workers chuckle:
     
    “The most configurable system is java.exe, and it is configured via javac.exe”
     
    Hope you enjoyed it as much as I did.
     
    -Bill
    1:17 PM | Add a comment | Permalink | Blog it