Content Types
A
PTC Arbortext Layout Developer document contains a copy of the XML instance being formatted plus a number of other content objects held in tags. Refer to
Stylesheets, Templates, and Documents for information. Each content object is held in an
PTC Arbortext Layout Developer tag.
PTC Arbortext Layout Developer has a number of different tag types to support the different content types that its documents can contain.
Document content falls into three groups:
• Non-XML text content — plain text that may or may not contain markup
Markup is essential in PTC Arbortext Layout Developer to support the association of formatting properties with text. It is possible to style text content that is not of XML format, well formed, or structured.
Plain text in an PTC Arbortext Layout Developer document is of tag type .tx, known as a text stream.
• XML content
Two tag types hold XML content:
◦ .xm (XML stream) — has an associated read-only DOM against which XPath expressions can be performed and XSLT run.
◦ .xd (XML DOM stream) —a read-write XML DOM content type. XML DOM streams behave similarly to XML streams. As an added benefit they can manipulate the DOM tree using W3C DOM Level 2 Core functionality.
• Graphical content
Two tag types hold graphical content:
◦ .og (object graphic) — equivalent to vector graphics
◦ .rg (raster graphic) — equivalent to bitmap graphics
All PTC Arbortext Layout Developer content types can either be linked to the current PTC Arbortext Layout Developer document or loaded into it. Typically, graphical content is linked and text content is loaded, as changes to text content are likely but changes to graphics are not.