jQuery cookies, set last visited page and redirect to last visited on new session

Question

So I am building an app for a client in jQuery, this is placed in an IFrame on their website. This app reads data from a JSON that is generated by their CMS and then sets page layouts etc from a query string.

The client me to set a cookie of the last visited page when linked off to an external page. Then on coming back to the app it will check if a cookie has been set, if so then redirect to that last visited page.

I am using https://github.com/carhartl/jquery-cookie plugin for easier cookie integration.

My code so far:

//Get current URL
var complete_url = document.URL;

//Define last location cookie
var last_location = $.cookie('last_location');

//On page read set last_location as current location
$(document).ready(function() {
    $.cookie('last_location', complete_url, {
        expires: 0,
        path: '/'
    });
});

//if page_location is set navigate to that location
if (last_location && last_location != complete_url) {
    window.location = last_location;
}

This obviously doesn't work as you'd get stuck in an infinite loop and I am struggling to get this right as it is my first day back at work from Christmas, ha.

If you are able to help that would be great!

Also I'm sorry if this is unclear I can try and reword it if need be.

Thanks.

[NOT SOLVED]

var pattern = new RegExp(window.location.host);

$('a').click(function() {
    var href = $(this).attr('href');
    if(pattern.test(href) !== true) {
        $.cookie('last_location', document.URL, {
            expires: 7,
            path: '/'
        });
    }
});

var referrer = window.parent.document.referrer,
    current = document.domain;

if(referrer.indexOf(current) === -1) {
    var last_location = $.cookie('last_location'),
        current_location = document.URL;

    if(typeof last_location !== 'undefined' && last_location !== current_location) {
        $.removeCookie('last_location');
        window.location = last_location;
    }
}

[NEW SOLUTION]
I have come up with a new solution that doesn't depend on the document.referrer

var last_location = $.cookie('last_location'),
    current_location = document.URL;

//Initial check if cookie is set and not equal to current location
if (last_location && last_location !== current_location) {
    window.location = last_location;
}

//Set pattern
var pattern = new RegExp(window.location.host);

//On any link click test if the href does not have a match with the pattern
$('a').click(function() {
    var href = $(this).attr('href');
    if (pattern.test(href) !== true) {
        //If no match found, the link is external and adding current url to the cookies
        $.cookie('last_location', document.URL, {
            expires: 1,
            path: '/'
        });
    } else {
        //Else if link is internal remove cookie and continue as normal
        $.removeCookie('last_location', {
            path: '/'
        });
    }
});

Answer 1

I would set the cookie when the user is linked off to an external page and not everytime he visit a page of your client's website. So I put an event listener to this links.

$('.your_external_links').on('click', function(evt){
    $.cookie('last_location', document.URL, {
        expires: 7, // Please read the [NOTE_1]
        path: '/'
    }
}

[NOTE_1]

Reading the documentation of the cookie plugin, the expire section says:

expires

Define lifetime of the cookie. Value can be a Number which will be interpreted as days from time of creation or a Date object. If omitted, the cookie becomes a session cookie. So if you want that cookie never expire put a big number inside of this. For example: "expires: 9999"

[END NOTE_1]

Then when the user comes back I'll check if he comes from an outside link. If so I'll check also the cookie and redirect the user to the last location visited.

var comesFromUrl  = document.referrer,
    mySiteDomain = document.domain;

// Check if user comes from an external domain
if(comesFromUrl.indexOf(mySiteDomain) === -1) {
    var last_location    = $.cookie('last_location'),
        current_location = document.URL;

    // Check if cookie exists and if its value is not the current location
    if(typeof last_location !== "undefined"
       && last_location !== current_location) {
        // Here is possible to choose if remove the cookie or refresh it. It's up to you.
        $.removeCookie('last_location');
        window.location = last_location;
    }
}