Once the structure of the XML document and the required restrictions on the elements and attributes are fixed with an XML schema the editing of the document is easier in a WYSIWYG (what-you-see-is-what-you-get) editor in which the XML markup is not visible.
This tagless editor is available as the Author mode of the XML editor. The Author mode is activated by pressing the Author button at the bottom of the editing area where the mode switches of the XML editor are available: Text, Grid and Author (see the following screenshot). The Author mode renders the content of the XML document visually based on a CSS stylesheet associated with the document. Many of the actions and features available in Text mode are also available in Author mode.
The tagless rendering of the XML document in the Author mode is driven by a CSS
stylesheet which conforms to the version 2.1 of the
CSS specification from the W3C consortium. Also some CSS 3 features like
namespaces and custom extensions of the CSS specification are supported.
The CSS specification is convenient for driving the tagless rendering of XML documents as it is an open standard maintained by the W3C consortium. A stylesheet conforming to this specification is very easy to develop and edit in <oXygen/> as it is a plain text file with a simple syntax.
The association of such a stylesheet with an XML document is also straightforward: an xml-stylesheet XML processing instruction with the attribute type="text/css" must be inserted at the beginning of the XML document. If it is an XHTML document, that is the root element is a html element, there is a second method for the association of a CSS stylesheet: an element link with the href and type attributes in the head child element of the html element as specified in the CSS specification.
There are two main types of users of the Author mode: developers and content authors. A developer is a technical person with advanced XML knowledge who defines the framework for authoring XML documents in the tagless editor. Once the framework is created or edited by the developer it is distributed as a deliverable component ready to plug into the application to the content authors. A content author does not need to have advanced knowledge about XML tags or operations like validation of XML documents or applying an XPath expression to an XML document. He just plugs the framework set up by the developer into the application and starts editing the content of XML documents without editing the XML tags directly.
The framework set up by the developer is called document type and defines a type of XML documents by specifying all the details needed for editing the content of XML documents in tagless mode: the CSS stylesheet which drives the tagless visual rendering of the document, the rules for associating an XML schema with the document which is needed for content completion and validation of the document, transformation scenarios for the document, XML catalogs, custom actions available as buttons on the toolbar of the tagless editor.
The tagless editor comes with some ready to use predefined document types for XML frameworks largely used today like DocBook, DITA, TEI, XHTML.