1\name{Doctype}
2\alias{Doctype}
3\alias{coerce,Doctype,character-method}
4\title{Constructor for DTD reference}
5\description{
6  This is a constructor for the \code{Doctype} class
7  that can be provided at the top of an XML document
8  to provide information about the class of document,
9  i.e. its DTD or schema.
10  Also, there is a method for converting such a \code{Doctype}
11  object to a character string.
12}
13\usage{
14Doctype(system = character(), public = character(), name = "")
15}
16\arguments{
17  \item{system}{the system URI that locates the DTD. }
18  \item{public}{the identifier for locating the DTD in a catalog, for
19    example. This should be a character vector of length 2, giving
20    the public identifier and a URI.  If just the public identifier
21    is given and a string is given for \code{system} argument,
22    the \code{system} value is used as the second element of
23    \code{public}.
24    The public identifer should be of the form
25    \code{+//creator//name//language}
26    where the first element is either + or -, and
27    the language is described by a code in the ISO 639 document.
28  }
29  \item{name}{the name of the root element in the document.
30    This should be the first parameter, but is left this way
31  for backward compatability.  And }
32}
33\value{
34 An object of class \code{Doctype}.
35}
36\references{\url{http://www.w3.org/XML}
37 XML Elements of Style, Simon St. Laurent.
38}
39\author{ Duncan Temple Lang }
40
41
42\seealso{
43 \code{\link{saveXML}}
44}
45\examples{
46
47  d = Doctype(name = "section",
48              public = c("-//OASIS//DTD DocBook XML V4.2//EN",
49                         "http://oasis-open.org/docbook/xml/4.2/docbookx.dtd"))
50  as(d, "character")
51
52   # this call switches the system to the URI associated with the PUBLIC element.
53  d = Doctype(name = "section",
54              public = c("-//OASIS//DTD DocBook XML V4.2//EN"),
55              system = "http://oasis-open.org/docbook/xml/4.2/docbookx.dtd")
56}
57\keyword{IO}
58
59