Beware Critical Update for Salesforce Lightning Users, Read Immediately !!

If you are using Visual Force pages used in Lightning Console, then this is very Important news for you...

Currently $User.UITheme or $User.UITheme Displayed returns Theme4d for Visual Force pages used in Lightning Console. 

Once the Critical Updates is activated, Theme4u will be returned for the case.

Learn Learning Salesforce Lightning Application Development to accelerate your Career with Salesforce!!! 

Customers need to make changes to their Visual Force code prior to activating the Critical Updates if they use the following type of code to determine whether the Visual Force page is used in Lightning:

function inLightningExperience() {

  return 'Theme4d' === '{!$User.UIThemeDisplayed}';

}

Instead, use the following code to determine whether it is in Lightning or not:

function inLightningExperience() {

  return ['Theme4d', 'Theme4u'].indexOf('{!$User.UIThemeDisplayed}') > -1; 

}

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