xml_children returns only elements, xml_contents returns
all nodes. xml_length returns the number of children.
xml_parent returns the parent node, xml_parents
returns all parents up to the root. xml_siblings returns all nodes
at the same level. xml_child makes it easy to specify a specific
child to return.
xml_children(x)
xml_child(x, search = 1, ns = xml_ns(x))
xml_contents(x)
xml_parents(x)
xml_siblings(x)
xml_parent(x)
xml_length(x, only_elements = TRUE)
xml_root(x)A document, node, or node set.
For xml_child, either the child number to return (by
position), or the name of the child node to return. If there are multiple
child nodes with the same name, the first will be returned
Optionally, a named vector giving prefix-url pairs, as produced
by xml_ns(). If provided, all names will be explicitly
qualified with the ns prefix, i.e. if the element bar is defined
in namespace foo, it will be called foo:bar. (And
similarly for attributes). Default namespaces must be given an explicit
name. The ns is ignored when using xml_name<-() and
xml_set_name().
For xml_length, should it count all children,
or just children that are elements (the default)?
A node or nodeset (possibly empty). Results are always de-duplicated.
x <- read_xml("<foo> <bar><boo /></bar> <baz/> </foo>")
xml_children(x)
#> {xml_nodeset (2)}
#> [1] <bar>\n <boo/>\n</bar>
#> [2] <baz/>
xml_children(xml_children(x))
#> {xml_nodeset (1)}
#> [1] <boo/>
xml_siblings(xml_children(x)[[1]])
#> {xml_nodeset (1)}
#> [1] <baz/>
# Note the each unique node only appears once in the output
xml_parent(xml_children(x))
#> {xml_nodeset (1)}
#> [1] <foo>\n <bar>\n <boo/>\n </bar>\n <baz/>\n</foo>
# Mixed content
x <- read_xml("<foo> a <b/> c <d>e</d> f</foo>")
# Childen gets the elements, contents gets all node types
xml_children(x)
#> {xml_nodeset (2)}
#> [1] <b/>
#> [2] <d>e</d>
xml_contents(x)
#> {xml_nodeset (5)}
#> [1] a
#> [2] <b/>
#> [3] c
#> [4] <d>e</d>
#> [5] f
xml_length(x)
#> [1] 2
xml_length(x, only_elements = FALSE)
#> [1] 5
# xml_child makes it easier to select specific children
xml_child(x)
#> {xml_node}
#> <b>
xml_child(x, 2)
#> {xml_node}
#> <d>
xml_child(x, "baz")
#> {xml_missing}
#> <NA>