Dynamically Hide Home Button in CRM 2015 using Ribbon Workbench not Working

Question

I am creating a custom Enable Rule to hide "Import" button in my custom entity in Ribbon Workbench. Here is my JS code:

function ShowHideButton() {
var context;
var serverUrl;
var UserID;
var ODataPath;
var toReturn;
context = Xrm.Page.context;
serverUrl = context.getClientUrl();
UserID = context.getUserId();
ODataPath = serverUrl + "/XRMServices/2011/OrganizationData.svc";
var retrieveUserReq = new XMLHttpRequest();
retrieveUserReq.open("GET", ODataPath + "/SystemUserSet(guid'" + UserID + "')", true);
retrieveUserReq.setRequestHeader("Accept", "application/json");
retrieveUserReq.setRequestHeader("Content-Type", "application/json; charset=utf-8");
retrieveUserReq.onreadystatechange = function () {
    toReturn = retrieveUserReqCallBack(this);      
};
retrieveUserReq.send();

return toReturn;
}

function retrieveUserReqCallBack(retrieveUserReq) {

var retrievedUser = this.parent.JSON.parse(retrieveUserReq.responseText).d;
var retrievedValue = retrievedUser.BusinessUnitId;
var id = retrievedValue.Id;
var refIdAdmin;
var refIdTL;
var refMember;

refIdAdmin = "6EF4BCC3-5608-E511-9415-22000A93809E";
refIdTL = "CCFE0C41-D208-E511-9416-22000A93809E";
refMember = "1010FC5F-2D2C-E511-941A-22000AA400C9";   

if (id.toUpperCase() == refIdAdmin) {

    return true;
}
else if (id.toUpperCase() == refIdTL) {

    return true;
}
else if (id.toUpperCase() == refMember) {
    return true;
}
else {

    return false;
}

}

can you please help me fix the code so that Ribbon Workbench is able to read what I want to return?

Answer 1

You're making async request and that is the problem your toReturn is null when the rule is validated

var request = new XMLHttpRequest();

request.open('GET', '/bar/foo.txt', false);  // false makes the request synchronous

request.send(null);

if (request.status === 200) {

console.log(request.responseText);

}