Subject Selector

Oxygen XML Editor Author supports the subject selector described in CSS Level 4 (currently a working draft at W3C http://www.w3.org/TR/selectors4/). This selector matches a structure of the document, but unlike a compound selector, the styling properties are applied to the subject element (the one marked with "!") instead of the last element from the path.

The subject of the selector can be explicitly identified by appending an exclamation mark (!) to one of the compound selectors in a selector. Although the element structure that the selector represents is the same with or without the exclamation mark, indicating the subject in this way can change which compound selector represents the subject in that structure.

table! > caption {
  border: 1px solid red;
}

A border will be drawn to the table elements that contain a caption as direct child.

This is different from:

table > caption {
  border: 1px solid red;
}

which draws a border around the caption.

Important: As a limitation of the current implementation the general descendant selectors are taken into account as direct child selectors. For example the two CSS selectors are considered equivalent:

a! b c

and:

a! > b > c