The Outliner view has the following available functions:
The Outliner displays a general tag overview of the current edited XML Document. It also shows the correct hierarchical dependencies between the tag elements, making it easier for the user to be aware of the document's structure and the way tags are nested.
The Expand more and Collapse all items of the popup menu available on the outliner tree enlarge or reduce the set of nodes of the edited document currently visible in the view. The tree expansion action is a faster alternative to mouse clicks on the plus signs of the tree when one wants to access quickly a node deeply nested in the hierarchy of document nodes. When a large number of nodes become expanded and the document structure is not clear any more the collapsing action clears the view quickly by reducing the depth of the expanded nodes to only one child of the currently selected node.