9.2. Elements containing images

Commonly, images are associated with elements. Certain elements in your DTD are meant to describe images that can occur in your document. Image elements normally specify the image to display as the value of an attribute of the element.

For example, the graphic element in the well-known DocBook DTD uses the fileref attribute to provide the filename of an image. The fileref attribute in the DocBook DTD has a declared attribute value of CDATA, allowing a character string to occur as the value of the attribute. This value of the fileref attribute specifies a file that contains the image data.

Other DTDs use external entities to refer to images. The value of the attribute that specifies the image is the name of an external NDATA entity that holds the image data.

Images that should appear in XML/SGML-Elements are shown by epcEdit as embedded images if epcEdit is told about the attribute that specifies an image. epcEdit examines the attribute value of this attribute to create an image that will appear immediately to the left of the end tag of the element.

It is determined by the style sheet settings whether an image should be displayed within an element : In the Images tab of the style sheet for an element, you can select the name of an attribute that specifies the image to display. The value of this attribute has to be declared as CDATA or ENTITY in the DTD. If the attribute has a CDATA value, it is interpreted as a file name (relative to the location of the document). If the attribute has an ENTITY value, the entity must be an external NDATA entity with a notation that is known to specify an image (see Notations).