Old post, but in case other people are looking, you can do the auto-shrink with something like this code snippet

function PopupEditor_ForceResize() {
    try {
        var popupDiv = window.top.$('.os-internal-ui-dialog-content');
        var popupIframe = window.top.$('.os-internal-ui-dialog-content iframe:first');
        var popupIframeOldHeight = popupIframe.height();
        
        // reduce iframe height to its contents
        var mainPopupHeight = document.getElementsByClassName('MainPopup')[0].clientHeight;
        popupDiv.height(mainPopupHeight);
        
        // pop-up editor already auto-grows, so we just need to address auto-shrink
        if (popupIframe.height() >= popupIframeOldHeight) {
            return false;
        }
        
        var result = window.top.RichWidgets_Popup_Editor_resize(popupDiv, -1, -1, false, {target: popupDiv});
        
        if (!result) {
            // something wrong happened in resize - reset iframe height
            popupIframe.height(popupIframeOldHeight);
        }
    } catch (err) {}
}

Usage:

Place that JS on your webscreen, then in a server action where you think your popup content can shrink, do a HTTPRequestHandler/RunJavaScript and call the action 

"PopupEditor_ForceResize();"

That code is from https://success.outsystems.com/Documentation/Development_FAQs/How_to_resize_a_pop-up_window

Happy OSing!

Hello, I have a similar problem as above and tried to use this solution without success.

In my case I have a Popup that presents a table (table records) with pagination (using the List-Navigation widget from Rich Widgets). The number of lines by page is 10, except in the last page. What I want is to the popup to shrink once it gets to the last page (when there are fewer lines).

I've tried to implement this solution by copying the code to the javascript field of the Webscreen (of my popup), and placing the RunJavaScript action on the PageRefresh action associated with the OnNotify field of the List-Navigation widget.

I haven't changed anything in the code and have placed the RunJavascript action after the ajaxrefresh (that refreshes the main div of the pop-up) widget in my PageRefresh action.

I am using serice studio version 7.0.