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JSON-LD blocks

Source: R/metadata.R
html_json_ld.Rd

The structured data pages embed as JSON-LD: the text of each <script type="application/ld+json"> below the given nodes (and the nodes themselves), in document order. The type is matched as a MIME type: case-insensitively, ignoring surrounding whitespace and any parameters.

Usage

html_json_ld(x, parse = FALSE)

Arguments

x

A zuhtml_document or zuhtml_nodeset.

parse

If TRUE, parse each block with jsonlite::fromJSON() (with simplifyVector = FALSE, so objects are named lists and arrays are lists). This needs the jsonlite package. A wrapper around the whole block, <![CDATA[ ... ]]> or <!-- ... -->, optionally commented out with // or /* */ as pages often do, is removed first.

Value

With parse = FALSE, a character vector: the text of each block, exactly as written. With parse = TRUE, a list as long as that vector: each block's parsed value, or NULL for a block that is not valid JSON; the texts are kept in its attribute "json".

See also

Other metadata: html_meta(), html_microdata(), html_title()

Examples

doc <- html_parse(paste0(
  "<script type='application/ld+json'>",
  '{"@context": "https://schema.org", "@type": "Person", "name": "Ada"}',
  "</script>"
))
html_json_ld(doc)
#> [1] "{\"@context\": \"https://schema.org\", \"@type\": \"Person\", \"name\": \"Ada\"}"
if (requireNamespace("jsonlite", quietly = TRUE)) {
  html_json_ld(doc, parse = TRUE)[[1]]$name
}
#> [1] "Ada"