xml2: xml_children – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

xml_children

Navigate around the family tree.

Description

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.

Usage

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)

Arguments

`x`	A document, node, or node set.
`search`	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
`ns`	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()`.
`only_elements`	For `xml_length`, should it count all children, or just children that are elements (the default)?

Value

A node or nodeset (possibly empty). Results are always de-duplicated.

Examples

x <- read_xml("<foo> <bar><boo /></bar> <baz/> </foo>")
xml_children(x)
xml_children(xml_children(x))
xml_siblings(xml_children(x)[[1]])

# Note the each unique node only appears once in the output
xml_parent(xml_children(x))

# 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_contents(x)

xml_length(x)
xml_length(x, only_elements = FALSE)

# xml_child makes it easier to select specific children
xml_child(x)
xml_child(x, 2)
xml_child(x, "baz")

xml2

Parse XML

v1.3.2

GPL (>= 2)

Authors

Hadley Wickham [aut], Jim Hester [aut, cre], Jeroen Ooms [aut], RStudio [cph], R Foundation [ctb] (Copy of R-project homepage cached as example)

Initial release