Sliders/Galleries/Maps Inside Popups
All types and forms of slider, gallery, and image plugins are compatible with Popup Maker. Simply entering the shortcode for your slider into the Popup Content Editor will create a popup with your slider inside of it!
Depending on what slider builder or plugin you're using, the slider content may appear too small (thumbnail), or not appear at all.
As such, the Slider ends up with heights of 0-50 depending if you had a popup title (thumbnail).
In other words, the popups are not visible when they initialize the sliders.
Use a Custom Popup Size found in the Display Settings Pane of the Popup Editor, then define specific height and width, as seen here:
Wrap your slider in a <div> by using Text Tab of the Popup Content Editor, as seen here:
Copy past the code below and use your slider shortcode:
Revolution Slider Solution
If you use CSS, you can use media queries to scale it for different devices.
An alternative to Solution #2 is to add the following custom code to your RevSlider. Learn how to add custom code to your RevSlider.
Every Other Slider Solution
This solution is basically the same as the one for RevSlider, except it is for general use - it should even work with RevSlider as well!
Either add the following PHP code to your parent or child theme functions.php file, or pass it into a plugin like 'My Custom Functions'.
[Note: If you add the code to your theme functions.php file, copy everything from line 3 and below. Otherwise, your site will throw an error.]