pubUp.js

String.prototype.replaceAt = function () {
    var rlen = arguments[2] == null ? 1 : arguments[2];
    return this.substring(0, arguments[0]) + arguments[1] + this.substring(arguments[0] + rlen);
};
var currentItem = SDL.Client.UI.ApplicationHost.ViewModels.Navigation.currentNavigationItem();
var navHappy = {
    init: function () {
        this.newSrc = this.getNewSrc();
    },
    getCurrentItem: function () {
        return SDL.Client.UI.ApplicationHost.ViewModels.Navigation.currentNavigationItem();
    },
    getCurrentSrc: function () {
        var currentItem = this.getCurrentItem();
        return currentItem.targetDisplay.src;
    },
    getCurrentTCM: function () {
        var currentSrc = this.getCurrentSrc();
        return currentSrc.slice(currentSrc.indexOf("tcm:")+4, currentSrc.length);
    }, 
    getCurrentPublicationNumber: function () {
        var currentTCM = this.getCurrentTCM();
        return currentTCM.slice(0, currentTCM.indexOf("-"));
    },
    getNewPublicationNumber: function () { 
        return parseInt(this.getCurrentPublicationNumber(), 10) -1;
    },
    getNewTCM: function () {
        var currentTCM = this.getCurrentTCM();
        return currentTCM.replaceAt(0, this.getNewPublicationNumber());
    },
    getNewSrc: function () {
        var currentSrc = this.getCurrentSrc(),
            currentTCM = this.getCurrentTCM(),
            newTCM = this.getNewTCM();
        return currentSrc.replace(currentTCM, newTCM );
    },
    goToNewPublication: function () {
        window.location = this.getNewSrc();
    }
};
navHappy.init();