disable viewport zooming iOS 10+ safari?

Question

I've update my iPhone 6 plus to iOS 10 beta version and just found that in mobile safari, you can zoom any webpages by double tapping or pinching IGNORE the user-scalable=no code in the meta tag. I don't know whether it's a bug or feature. If it's considered as a feature, how do we disable viewport zooming iOS 10 safari ?

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updated on iOS 11/12 release, iOS 11 and iOS 12 safari still DO NOT respect the user-scalable=no meta tag.

Answer 1

In my particular case, I am using Babylon.js to create a 3D scene and my whole page consists of one full screen canvas. The 3D engine has its own zooming functionality but on iOS the pinch-to-zoom interferes with that. I updated the the @Joseph answer to overcome my problem. To disable it, I figured out that I need to pass the {passive: false} as an option to the event listener. The following code works for me:

window.addEventListener(
    "touchmove",
    function(event) {
        if (event.scale !== 1) {
            event.preventDefault();
        }
    },
    { passive: false }
);

Answer 2

I checked all above answers in practice with my page on iOS (iPhone 6, iOS 10.0.2), but with no success. This is my working solution:

$(window).bind('gesturestart touchmove', function(event) {
    event = event.originalEvent || event;
    if (event.scale !== 1) {
         event.preventDefault();
         document.body.style.transform = 'scale(1)'
    }
});

Answer 3

I spent about an hour looking for a more robust javascript option, and did not find one. It just so happens that in the past few days I've been fiddling with hammer.js (Hammer.js is a library that lets you manipulate all sorts of touch events easily) and mostly failing at what I was trying to do.

With that caveat, and understanding I am by no means a javascript expert, this is a solution I came up with that basically leverages hammer.js to capture the pinch-zoom and double-tap events and then log and discard them.

Make sure you include hammer.js in your page and then try sticking this javascript in the head somewhere:

< script type = "text/javascript" src="http://hammerjs.github.io/dist/hammer.min.js"> < /script >
< script type = "text/javascript" >

  // SPORK - block pinch-zoom to force use of tooltip zoom
  $(document).ready(function() {

    // the element you want to attach to, probably a wrapper for the page
    var myElement = document.getElementById('yourwrapperelement');
    // create a new hammer object, setting "touchAction" ensures the user can still scroll/pan
    var hammertime = new Hammer(myElement, {
      prevent_default: false,
      touchAction: "pan"
    });

    // pinch is not enabled by default in hammer
    hammertime.get('pinch').set({
      enable: true
    });

    // name the events you want to capture, then call some function if you want and most importantly, add the preventDefault to block the normal pinch action
    hammertime.on('pinch pinchend pinchstart doubletap', function(e) {
      console.log('captured event:', e.type);
      e.preventDefault();
    })
  });
</script>