How to create a link WITHOUT opening a new window

Note the following article on FileMaker's website:

http://help.filemaker.com/app/answers/detail/a_id/408/~/open-url-is-not-working-when-used-via-instant-web-publishing

They seem to offer us only a single, rather silly, solution: tell your viewers to disable pop-up blockers.  But this is 2015.  Mobile devices dominate.  Pop-up blockers sometimes CANNOT be disabled.  And even if you can, you probably SHOULDN'T!  As such, it is quite foolish in this day and age for FileMaker to not offer us a more seamless solution.  Nevertheless, I am posted this problem here to see if any of you know a workaround.

Some may be apt to flippantly say to me, "Just use a Web Viewer in your database."  But as you know, there are times when you want the user to click a button in your database and then have the linked content only to display after they have logged in separately for that.  I have that setup now, in fact.  My FileMaker IWP database automatically logs everyone in because the basic content in the database is PUBLIC.  But there are associated documents (PDFs mainly) that I need to make available to users of that database which need to be secured by at Password.  I have that setup now, but the problem is that when the user clicks the button to access the Authentication Sheet for access to the PDFs, it is blocked on mobile devices.  They won't display the content on iPhones or iPads due to pop-up blocking.  And the only silly reason for this is because FileMaker is trying to open the content in a new Window/Tab rather than the EXISTING window.  If it opened in the existing window, there would be no issues with pop-up blocking at all.

So what is the solution for this?

Thank you.