Method:

Method: Adds “Opt in” or “Opt out” link to the main “Plugins” page link actions collection.

Method: During trial promotion the “upgrade” submenu item turns to “start trial” to encourage the trial. Since we want to keep the same menu item handler and there’s no robust way to add new arguments to the menu item link’s querystring, use JavaScript to find the menu item and update the href of the link.

Method:

Method: Checks if given API result is a non-empty and not an error object.

Method: Checks if given API result is a non-empty entity object with non-empty ID.

Method: Make sure a given argument is an array of a specific type.

Method:

Method: Send a JSON response back to an Ajax request, indicating failure.