Javascript on masterpage returns undefined

Question

_spBodyOnLoadFunctionNames.push("FetchURL");
                function FetchURL()
                {
                    // Custom JavaScript methods
                   var ctx = new SP.ClientContext();
        var site = ctx.get_site();
        ctx.load(site);
        ctx.executeQueryAsync(function(s, a){ currURL=SP.Utilities.Utility.getLayoutsPageUrl("");
                                            });
                    }

The above method returns the URL, however, sometimes it returns undefined, which causes errors. How to tackle this?

Code is placed in head of the masterpage... in scripts tag.

Answer 1

The SP.Utilities.Utility.getLayoutsPageUrl is contained within the sp.js file. You have to make sure that sp.js has been loaded, before calling the function.

SP.SOD.executeFunc('sp.js', 'SP.Utilities.Utility.getLayoutsPageUrl', getCurrentUrl);

function getCurrentUrl(){
  currentURL = SP.Utilities.Utility.getLayoutsPageUrl(""); 
}