Capturing User details for re-using throughout a Sencha app

app.js

Ext.Ajax.request({
    url:  'userEndpointUrl',
    failure: function(data, operation) {
        console.log('failure while trying to fetch roles for user..');
        console.log(operation);
    },
    success: function(data, operation) {
        console.log('success fetching roles....');
        var response = Ext.JSON.decode(data.responseText);
        // initialize User in the app
        User.initUser(response.userName, response.rights);
    }
});

Usage.js

onMenuPanelRenderer : function() {
  var hasWebRole = User.hasRole(Config.role.web);
  var hasAdminRole = User.hasRole(Config.role.admin);
   
  if (hasWebRole) {
    // set mentu item visible true based on role
  }
   
  if (hasAdminRole) {
    // set mentu item visible true based on role
  }
}

User.js

Ext.define('AppName.app.User', {
    singleton: true,
    alternateClassName: ['User'],
    constructor: function(config) {
        this.initConfig(config);
    },
    config: {
        username: null,
        rights: null
        // probably some more details

    },
    initUser : function(username, rights) {
        this.username = username;
        this.rights = rights;
        return this;
    },
    getRights: function() {
        return this.rights;
    },
    hasRole: function(role) {
        var rights = User.getRights();
        for (i = 0; i < rights.length; i++) {
            if (rights[i] === role) {
                return true;
            }
        }
        return false;
    }
});