https://github.com/cran/XML
Tip revision: d8b36ec3455b754f80d5cfaaa3e5e249e28bcb08 authored by Duncan Temple Lang on 25 June 2009, 00:00:00 UTC
version 2.5-3
version 2.5-3
Tip revision: d8b36ec
xmlNode.Rd
\name{xmlNode}
\alias{xmlNode}
\alias{xmlTextNode}
\alias{xmlPINode}
\alias{xmlCDataNode}
\alias{xmlCommentNode}
\title{Create an XML node}
\description{
These functions allow one to create XML nodes
as are created in C code when reading XML documents.
Trees of XML nodes can be constructed and
integrated with other trees generated manually
or with via the parser.
}
\usage{
xmlNode(name, ..., attrs=NULL, namespace="", namespaceDefinitions = NULL, .children = list(...))
xmlTextNode(value, namespace="", entities = XMLEntities, cdata = FALSE)
xmlPINode(sys, value, namespace="")
xmlCDataNode(...)
xmlCommentNode(text)
}
\arguments{
\item{name}{The tag or element name of the XML node. This is what appears
in the elements as \code{<name> .. </name>}}
\item{\dots}{The children nodes of this XML node.
These can be objects of class \code{XMLNode}
or arbitrary values that will be converted to a string
to form an \code{XMLTextNode} object.}
\item{.children}{an alternative mechanism to specifying the children
which is useful for programmatic use when one has the children
in an existing list. The \dots mechanism is for use when the
children are specified directly and individually.
}
\item{attrs}{A named character vector giving the
name, value pairs of attributes for this XML node.}
\item{value}{This is the text that is to be used when forming
an \code{XMLTextNode}.}
\item{cdata}{a logical value which controls whether the text
being used for the child node is to be first
enclosed within a CDATA node to escape special characters such
as \code{>} and \code{&}.
}
\item{namespace}{The XML namespace identifier for this node.}
\item{namespaceDefinitions}{a collection of name space definitions, containing the prefixes and the corresponding URIs.
This is most conveniently specified as a character vector whose names attribute is the vector of prefixes
and whose values are the URIs. Alternatively, one can provide a list of name space definition objects
such as those returned}
\item{sys}{the name of the system for which the processing instruction
is targeted. This is the value that appears in the
\code{<?sys value?>}}
\item{text}{character string giving the contents of the comment.}
\item{entities}{a character vector giving the mapping
from special characters to their entity equivalent.
This provides the character-expanded
entity pairings of 'character = entity' , e.g. '<' = "lt" which are
used to make the content valid XML
so that it can be used within a text node.
The text searched sequentially
for instances of each character in the names and each instance is
replaced with the corresponding '&entity;' }
}
\value{
An object of class \code{XMLNode}.
In the case of \code{xmlTextNode},
this also inherits from \code{XMLTextNode}.
The fields or slots that objects
of these classes have
include
\code{name}, \code{attributes}, \code{children} and \code{namespace}.
However, one should
the accessor functions
\code{\link{xmlName}},
\code{\link{xmlAttrs}},
\code{\link{xmlChildren}}
and
\code{\link{xmlNamespace}}
}
\references{\url{http://www.w3.org/XML}, \url{http://www.jclark.com/xml},
\url{http://www.omegahat.org} }
\author{ Duncan Temple Lang }
\seealso{
\code{\link{addChildren}}
\code{\link{xmlTreeParse}}
\code{\link{asXMLNode}}
\code{\link{newXMLNode}}
\code{\link{newXMLPINode}}
\code{\link{newXMLCDataNode}}
\code{\link{newXMLCommentNode}}
}
\examples{
# node named arg with two children: name and defaultValue
# Both of these have a text node as their child.
n <- xmlNode("arg", attrs = c(default="TRUE"),
xmlNode("name", "foo"), xmlNode("defaultValue","1:10"))
# internal C-level node.
a = newXMLNode("arg", attrs = c(default = "TRUE"),
newXMLNode("name", "foo"),
newXMLNode("defaultValue", "1:10"))
xmlAttrs(a) = c(a = 1, b = "a string")
xmlAttrs(a) = c(a = 1, b = "a string", append = FALSE)
newXMLNamespace(a, c("r" = "http://www.r-project.org"))
xmlAttrs(a) = c("r:class" = "character")
xmlAttrs(a[[1]]) = c("r:class" = "character")
# Using a character vector as a namespace definitions
x = xmlNode("bob",
namespaceDefinitions = c(r = "http://www.r-project.org",
omg = "http://www.omegahat.org"))
}
\keyword{file}