I have solved this by cloning the menu when the browser size is reduced (using Harvey: http://harvesthq.github.io/harvey/) and only activating it with mmenu at this point. When I resize back up, I delete the cloned mobile version of the menu, and then show the desktop menu again. One problem I faced was that if you resize back up to desktop with the mobile menu expanded, it didn't automatically close. I fixed this by adding a trigger event to close it before removing the mobile version.
Markup:
<ul id="menu">
<li class="menu-item">
<a href="">Home</a>
</li>
.....
</ul>
Jquery:
$( document ).ready(function() {
/* Add and remove the mobile version of the menu */
var toggleMenu = {
elem: $("#menu"),
mobile: function(){
//clone the existing top menu and append it to the mobile menu
var menu = this.elem.clone(true).addClass("mobile-added").appendTo("#mobile-menu");
//activate mmenu
$("#mobile-menu").mmenu({
position: "right",
zposition: "back",
});
//hide desktop top menu
this.elem.hide();
},
desktop: function(){
//close the menu
$("#mobile-menu").trigger("close.mm");
//remove cloned menu
$('.mobile-added').remove();
//reshow desktop menu
this.elem.show();
}
};
Harvey.attach('screen and (max-width:1024px)', {
setup: function(){ // called when the query becomes valid for the first time
},
on: function(){ // called each time the query is activated
toggleMenu.mobile();
},
off: function(){ // called each time the query is deactivated
}
});
Harvey.attach('screen and (min-width:1025px)', {
setup: function(){ // called when the query becomes valid for the first time
},
on: function(){ // called each time the query is activated
toggleMenu.desktop();
},
off: function(){// called each time the query is deactivated
}
});
});