[SalesForce] way to detect if a Lightning Component is running in a Community or in Lightning Experience

One of the techniques I use to debug is create a lightning App and use the component inside the app and only once it is perfectly ready I host it on community .

The problem with community is everytime you change you have to preview and publish and that takes lot of time .

Instead create a lightning App .A sample below

<aura:application>
  <c:MorgageComponent/>
</aura:application>

You can open in SFDC with URL /c/MortgageApp.app where MortgageApp is the App name and then you can debug in the browser console .This is really simpler compared to debugging with community skin .

Having not received any official feedback on this, here is what we implemented. This is not a future proof solution because it relies on the domain, but from my research it seems unlikely that the domain will change. Note that sitestudio is not included as the actual site is served in an iframe when in the builder.

/**
 * Get whether the current window is in the community builder or community site
 * preview.
 * @param  {String} url The url to check. If null, the current hostname will be
 *                        used.
 * @return {Boolean}    True if the current window is a preview.
 */
getIsSitePreview: function(url) {
  var urlToCheck = url;
  if(!urlToCheck) {
    urlToCheck = window.location.hostname;
  }
  urlToCheck = urlToCheck.toLowerCase();
  return urlToCheck.indexOf('sitepreview') >= 0 || urlToCheck.indexOf('livepreview') >= 0);
}

This has allowed us to meet our requirements for now. Hopefully Salesforce just adds a context varible to the community interface that allows us to get at this but in the meantime I think this is the best option.