I was attempting to create an accordion on a page using Bootstrap v.4.0 following this example
I need to set the aria-expanded and aria-controls properties of the A element.
In the UI for the page, I edit the properties of the A element, select the HTML Attributes tab, click on Show All Attributes and scroll down to the blank box at the bottom.
I am able to add a 'data-toggle' property, with the value 'collapse'
When I try to add a 'aria-expanded' property with the value 'false' a message flashes up in green saying that it has been added and saved with the value false, but when I close the edit properties box, the property disappears.
If I examine the resulting page in a browser, the aria-expanded property does not show up in the page source.
How should I add and set these properties ?
(Structr 2.1.3)