jQuery AJAX后退按钮问题

Question

This is a bit weird to explain so ill do my best.

Im working on a mobile site that im trying to shape into an ios app (eventually). On this page i have a menu button that on click, shows/hides menu.

Everything for the most part is working but, the problem is that when you click on the "back" button and the browser runs out of previous locations to go back to, the menu button breaks. When you click it, nothing happens. it behaves as though nothing is there.

The errors go like this, if on index(or first page), you click ONE link to go forward, and then on the browser hit the back button, it breaks instantly.

If your on the index, and hit for example, 5 links in any order(essentially you went forward 5xs) and thereafter, you hit back up to 4xs, the menu still works....you can essentially keep pressing links forward and be fine, hit back as far as you want and stop short one less than the total times you went forward and still be fine.

As soon as you hit the maximum backs, and theres nothing left in the history of page locations to go back to, the menu then breaks.

here is the link of this dummy site im working on (on my server) NOTE: to test, when it loads, manually shrink the browser to about 400 width so you can see the page take effect.

EDIT** woops forgot the link http://somdowprod.net/4testing/mobile/less1.html

and here is my code

javascript:(i left comments in there, so you can see where my logic is at...maybe im going about it wrong?)

// JavaScript Document
$(document).ready(function(){
var newHash = "";
var menuBtn = $('.leftButton');

    //~~~~~~~~~~~~~~~~~~~~~~~~~~~menu show/hide
    menuBtn.click( menuShowHide);
    //===========================//

    //~~~~~~~~~~~~~~~~~~~~~~~~~~~MENU SHOW / HIDE
    function menuShowHide(){
        $('#menu').toggleClass();

//      if($('#menu').css("display") == "none"){
//          $('#menu').css("display","block");
//      }   else {
//          $('#menu').css("display","none");   
//      }
        scroll(0,0);    
    }
    //===========================//


    //~~~~~~~~~~~~~~~~~~~~~~~~~~~ACTIONS FOR THE is-loaded trick.
        function isLoaded(){
            $('#progress').remove();    
        }
    //===========================//



    //~~~~~~~~~~~~~~~~~~~~~~~~~~~ACTIONS FOR THE HOME PAGE
        if(newHash == ""){
            $('body').append('<div id="progress">Loading...</div>');//attach this div which is made to look like a loading bubble.
            $('#contentHere').load('index.html #content', isLoaded);//load the content div from the index.html file
        }
    //===========================//




    //~~~~~~~~~~~~~~~~~~~~~~~~~~~Load the clicked content into my container via jQuery AJAX
    $('#menu a').click(function(){
        menuShowHide();
        window.location.hash = $(this).attr('href');
        return false; //doesnt let the link jump to a new page

    });

    $(window).bind('hashchange',function(){
        newHash = window.location.hash.substring(1);
        $('body').append('<div id="progress">Loading...</div>');//attach this div which is made to look like a loading bubble.
        $('#contentHere').load(newHash, isLoaded);
        //console.log(newHash); 

    });

    //===========================//



});

Anyone have any ideas as to whats making the menu break? Thanks in advanced.

Answer 1

The hashchange event is known to be unpredictable with the browsers back button.

Here's what's happening. When you back all the way to the beginning, the whole less.html page is being loaded into its own 'contentHere' container, and since document.ready won't be called on this subpage, no menuButton.click handler will be assigned to the links, so clicking them will not do anything.

Although being able to use your browsers back and forward buttons on asynchronous changes would be a neat feature, I don't think people would miss it enough for you to try to hack a workaround. People are used to not being able to use the back and forward button on asynchronously loaded content. They would try it once, see that it takes them to your site's referrer, hit forward, and subconciously make a mental note to use your menu instead of the back and forward buttons.

Probably a better suggestion, however, is to get rid of the AJAX feature altogether and let the links act the way that people expect them to. Okay, so you lose the cool 'Loading' modal and you save the user a tiny bit of time, but then you aren't confusing people's expectations about your interface.

Edit: to answer your question below, instead of using load() to get static content (which is overkill), put all of the content as sections in your less.html file and hide/unhide it using the menu selections. Here are two ways to accomplish this, each with their own advantages and disadvantages:

1. Fix your header with CSS (including the menu) (example: lifeinthegrid.com/simple-css-fixed-header/) and then make your menu links normal anchor links with no JavaScript event handler. When you click a link in the menu, the content jumps to that section and because your header is fixed, it has the feel of being a very fast httpRequest. Advantages: minimal JavaScript, the browser's back and forward buttons will work. Disadvantages: fixed elements are a nuisance on older smartphones, the next section might sneak into the bottom of the viewport and ruin the illusion. Solution: put more space between them.

2. The other method is to use show()/hide() on the different content sections. So let's say you click 'about us'. All of the sections are hidden and the 'about us' content is shown. Advantages: It's not as annoying as a fixed element, you can spice it up with FadeIn()/FadeOut() or other JQuery animation effects. Disadvantages: your browsers history will not track these changes unless you do some window.location hackery.