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Source: R/node.R
html_children.Rd

Move from nodes to related nodes. Operations that return exactly one node per input node – html_parent(), html_next_sibling() and html_previous_sibling() – are aligned: the result has the same length as x, with a missing node where there is no answer, so that results line up with their inputs. Operations that can return many nodes per input – html_children(), html_ancestors() and html_template_content() – return the set of all results, without duplicates, in document order.

Usage

html_children(x, elements_only = TRUE)

html_parent(x)

html_ancestors(x)

html_next_sibling(x, elements_only = TRUE)

html_previous_sibling(x, elements_only = TRUE)

html_template_content(x)

html_root(x)

html_document(x)

Arguments

x

A zuhtml_document or zuhtml_nodeset. A document stands for its document node.

elements_only

If TRUE, consider element nodes only, skipping text, comments and other nodes.

Value

  • html_children(), html_ancestors(), html_template_content(): a zuhtml_nodeset in document order. html_ancestors() does not include the document node.

  • html_parent(), html_next_sibling(), html_previous_sibling(): a zuhtml_nodeset as long as x, with missing nodes where there is no parent or sibling.

  • html_root(): a zuhtml_nodeset of length one: the <html> element of a document, or the fragment node of a fragment.

  • html_document(): the zuhtml_document that owns x.

Details

A <template> element's contents are its children here, but they are inert: searches and text extraction do not descend into them. html_template_content() returns them explicitly.

See also

Other navigation: html_closest(), html_elements()

Examples

doc <- html_parse("<ul><li>One</li><li>Two <b>bold</b></li></ul>")
body <- html_children(html_root(doc))[2]
items <- html_children(html_children(body))
items
#> <zuhtml_nodeset[2]>
#> [1] <li>
#> [2] <li>
html_parent(items)
#> <zuhtml_nodeset[2]>
#> [1] <ul>
#> [2] <ul>
html_next_sibling(items)
#> <zuhtml_nodeset[2]>
#> [1] <li>
#> [2] <missing>
html_ancestors(html_children(items[2]))
#> <zuhtml_nodeset[4]>
#> [1] <html>
#> [2] <body>
#> [3] <ul>
#> [4] <li>

# Template contents are reached explicitly:
tmpl <- html_parse("<template><p>inert</p></template>")
html_template_content(html_children(html_children(html_root(tmpl))[1]))
#> <zuhtml_nodeset[1]>
#> [1] <p>