The ff-class attribute allows you to add a css class to an element. Values beginning with _ & # are special values for greater control.
In this example, if isImportant is truthy
In this example, if the url contains the hash #red, the class red will be added to the div. Notice this example has no Firebase emulator because changing the hash has no effect on firebase or the view-model.
_selected will add the class selected when the list item is selected. _not-selected will add the class not-selected when the list item is not selected. You are responsible to setup the css class rules to hide and show the proper row.
See ff-select attribute