The name of the file containing the DTD to be processed.
asText
logical indicating whether the value of `extId' is the name of a file
or the DTD content itself. Use this when the DTD is read as a character vector, before being parsed
and handed to the parser as content only.
name
Optional name to provide to the parsing mechanism.
isURL
A logical value indicating whether the input source is to be
considred a URL or a regular file or string containing the XML.
DETAILS:
Parses and converts the contents of the DTD in the specified file
into a user-level object containing all the information about the DTD.
VALUE:
A list with two entries, one for the entities and the other for the elements
defined within the DTD. Note that only the external entities are returned (internal entities for use only while parsing the DTD are not included).
entities
a named list of the entities defined in the DTD (excluding ones defined for substitution only while parsing the DTD).
Each entry is indexed by the name of the corresponding entity.
Each is an object of class
XMLEntity
or alternatively
XMLExternalEntity if the entity refers
to an external definition.
The fields of these types of objects are
name
the name of the entity by which users refer to it.
content
the expanded value or definition of the entity
original
the value of the entity, but with references to other entities not expanded, but
maintained in symbolic form.
elements
a named list of the elements defined in the DTD, with the name of each element being
the identifier of the element being defined.
Each entry is an object of class
XMLElementDef
which has 4 fields.
name
the name of the element.
type
a named integer indicating the type of entry in the DTD, usually
either
element or
mixed.
The name of the value is a user-level type. The value is used for programming, both
internally and externally.
contents
a description of the elements that can be nested within this element.
This is an object of class
XMLElementContent
or one of its specializations -
XMLSequenceContent,
XMLOrContent.
Each of these encodes the number of such elements permitted
(one, one or more, zero or one, or zero or more);
the type indicating whether the contents consist of a single element type,
an ordered sequence of elements, or one of a set of elements.
Finally, the actual contents description is described in the
elements
field. This is a list of
one or more
XMLElementContent,
XMLSequenceContent and
XMLOrContent
objects.
defaultValue
the default value if it is specified, or the enumerated values as a character vector, if the type is Enumeration.a named list of the attributes defined for this element in the DTD.
Each element is of class
XMLAttributeDef which has 4 fields.
name
name of the attribute, i.e. the left hand side
type
the type of the value, e.g. an CDATA, Id, Idref(s), Entity(s), NMToken(s), Enumeration, Notation
defaultType
the defined type, one of None, Implied, Fixed or Required.
defaultValue
the default value if it is specified, or the enumerated values as a character vector, if the type is Enumeration.