How do I lock the orientation to portrait mode in a iPhone Web Application?

Question

This is a pretty hacky solution, but it's at least something(?). The idea is to use a CSS transform to rotate the contents of your page to quasi-portrait mode. Here's JavaScript (expressed in jQuery) code to get you started:

$(document).ready(function () {
  function reorient(e) {
    var portrait = (window.orientation % 180 == 0);
    $("body > div").css("-webkit-transform", !portrait ? "rotate(-90deg)" : "");
  }
  window.onorientationchange = reorient;
  window.setTimeout(reorient, 0);
});

The code expects the entire contents of your page to live inside a div just inside the body element. It rotates that div 90 degrees in landscape mode - back to portrait.

Left as an exercise to the reader: the div rotates around its centerpoint, so its position will probably need to be adjusted unless it's perfectly square.

Also, there's an unappealing visual problem. When you change orientation, Safari rotates slowly, then the top-level div snaps to 90degrees different. For even more fun, add

body > div { -webkit-transition: all 1s ease-in-out; }

to your CSS. When the device rotates, then Safari does, then the content of your page does. Beguiling!

You can specify CSS styles based on viewport orientation: Target the browser with body[orient="landscape"] or body[orient="portrait"]

http://www.evotech.net/blog/2007/07/web-development-for-the-iphone/

However...

Apple's approach to this issue is to allow the developer to change the CSS based on the orientation change but not to prevent re-orientation completely. I found a similar question elsewhere:

http://ask.metafilter.com/99784/How-can-I-lock-iPhone-orientation-in-Mobile-Safari

The following code was used in our html5 game.

$(document).ready(function () {
     $(window)    
          .bind('orientationchange', function(){
               if (window.orientation % 180 == 0){
                   $(document.body).css("-webkit-transform-origin", "")
                       .css("-webkit-transform", "");               
               } 
               else {                   
                   if ( window.orientation > 0) { //clockwise
                     $(document.body).css("-webkit-transform-origin", "200px 190px")
                       .css("-webkit-transform",  "rotate(-90deg)");  
                   }
                   else {
                     $(document.body).css("-webkit-transform-origin", "280px 190px")
                       .css("-webkit-transform",  "rotate(90deg)"); 
                   }
               }
           })
          .trigger('orientationchange'); 
});

I came up with this CSS only method of rotating the screen using media queries. The queries are based on screen sizes that I found here. 480px seemed to be a good as no/few devices had more than 480px width or less than 480px height.

@media (max-height: 480px) and (min-width: 480px) and (max-width: 600px) { 
    html{
        -webkit-transform: rotate(-90deg);
           -moz-transform: rotate(-90deg);
            -ms-transform: rotate(-90deg);
             -o-transform: rotate(-90deg);
                transform: rotate(-90deg);
        -webkit-transform-origin: left top;
           -moz-transform-origin: left top;
            -ms-transform-origin: left top;
             -o-transform-origin: left top;
                transform-origin: left top;
        width: 320px; /*this is the iPhone screen width.*/
        position: absolute;
        top: 100%;
            left: 0
    }
}