Temporarily hides the children of an element.
The children will be shown when the preview ends.
Tip
To visually remove elements during a preview, prefer hiding over detaching. See Prefer additive changes.
Example
This preview (visually) replaces the children of the targeted fragment
with a .spinner element:
up.preview('spinner', function(preview) {
preview.hideChildren()
preview.insert('<span class="spinner">Please wait...</span>')
})
For a more concise way to temporarily swap the children with a temporary element,
see the swapContent() method.
