Prevent orientation change in iOS Safari

There is no way to force a particular orientation in Mobile Safari; it'll always autorotate when the user rotates their device.

Perhaps you can display something for unsupported orientations informing the user that the orientations aren't supported, and that they need to rotate the device back in order to use your web app.

Jonathan Snook has a work around to this problem. In his slides here, he shows how to (sort of) lock to portrait (see slide 54 and 55).

The JS code from those slides:

window.addEventListener('orientationchange', function () {
    if (window.orientation == -90) {
        document.getElementById('orient').className = 'orientright';
    }
    if (window.orientation == 90) {
        document.getElementById('orient').className = 'orientleft';
    }
    if (window.orientation == 0) {
        document.getElementById('orient').className = '';
    }
}, true);

and the CSS:

.orientleft #shell {
    -webkit-transform: rotate(-90deg);
    -webkit-transform-origin:160px 160px;
}

.orientright #shell {
    -webkit-transform: rotate(90deg);
    -webkit-transform-origin:230px 230px;
} 

I tried to get this working for landscape on the iPhone, but it never looked 100% correct. I came close with the following jQueryian code, however. This would be within the onready function. Also note: this was within a "saved to homescreen" context, and I think that altered the position of the tranform-origin.

$(window).bind('orientationchange', function(e, onready){
   if(onready){
       $(document.body).addClass('portrait-onready');
   }
   if (Math.abs(window.orientation) != 90){
       $(document.body).addClass('portrait');
   } 
   else {
       $(document.body).removeClass('portrait').removeClass('portrait-onready');
   }
});
$(window).trigger('orientationchange', true); // fire the orientation change event at the start, to make sure 

And the CSS:

.portrait {
    -webkit-transform: rotate(90deg);
    -webkit-transform-origin: 200px 190px;
}
.portrait-onready {
    -webkit-transform: rotate(90deg);
    -webkit-transform-origin: 165px 150px;
}

Hope that helps someone get close to the desired result...