The Sandbox.UI.PseudoClass.Empty field represents the CSS pseudo-class :empty. This pseudo-class is used to select elements that have no children, including text nodes. It is part of the PseudoClass enumeration, which is used to apply various CSS pseudo-classes within the Sandbox UI styling system.
Use the Empty pseudo-class to apply styles to elements that do not contain any child elements. This can be useful for styling placeholders or default states for containers that are expected to have content.
// Example of using the :empty pseudo-class in a CSS style sheet
.my-container:empty {
background-color: lightgray;
border: 1px dashed #ccc;
padding: 10px;
text-align: center;
color: #999;
content: "No content available";
}