oXygen includes a powerful outliner, which is automatically synchronized with the document changes. The document tree structure is displayed as a document is edited. Modified elements are immediately revealed and selected in the outliner. An element can also be selected in the Text editor mode by clicking the corresponding node in the Outline view. The outliner uses an extremely fast and robust parser that is able to handle XML documents that are not "well-formed".
The Outline view, located in the bottom left part of the main editor window, offers the following features:
The XML Outliner displays a general overview of tags within the currently edited XML Document. It shows the hierarchical dependencies between the elements, making it easier for you to see the structure of the document.
When hovering over elements in the Outline view, a short text is displayed that describes each element from the tree. The description is composed of the value of the first attribute of a rendered element or the first few words from the text content. Options from the Outliner's toolbar allow you to filter attribute and text values.
When editing, the outliner dynamically follows the introduced modifications, scrolling to the node that is currently being modified. This gives you better insight on how the document is affected by the modifications.
The outliner can also be used to search for specific element locations and content in the edited document. When you select a node in the outliner tree, the document is scrolled to the position of the selected element and the content of the tag is highlighted in the document.
You can control which elements are displayed in the Outline view by entering element names into the filter box at the top of the view. If you type a text fragment in the filter box the outliner only displays the relevant components. For example, in the following image the element name figure is entered into the filter box, thus all elements corresponding to that name are displayed in the Outline view. For more advanced filtering, you can use wildcard characters (*,?) and separate multiple patterns with commas.
The following image shows another example where the filtered outliner is displayed as a tree. Only the elements that are parents or children of the element figure are displayed and the filtered elements are in boldface.
The Outline view displays XML validation errors and warnings by marking elements that have problems with a red or yellow icon. Additional details in regards to an error is displayed in a tool-tip, as illustrated in the following image.