Parse and process XML (and HTML) with xml2

Please note that the information presented in this post reflects the package as it stood when initially released, and may now be outdated. For the most up-to-date information, kindly refer to https://xml2.r-lib.org/.

I’m pleased to announced that the first version of xml2 is now available on CRAN. Xml2 is a wrapper around the comprehensive libxml2 C library that makes it easier to work with XML and HTML in R:

• Read XML and HTML with read_xml() and read_html().

• Navigate the tree with xml_children(), xml_siblings() and xml_parent(). Alternatively, use xpath to jump directly to the nodes you’re interested in with xml_find_one() and xml_find_all(). Get the full path to a node with xml_path().

• Extract various components of a node with xml_text(), xml_attrs(), xml_attr(), and xml_name().

• Convert to list with as_list().

• Where appropriate, functions support namespaces with a global url -> prefix lookup table. See xml_ns() for more details.

• Convert relative urls to absolute with url_absolute(), and transform in the opposite direction with url_relative(). Escape and unescape special characters with url_escape() and url_unescape().

• Support for modifying and creating xml documents in planned in a future version.

This package owes a debt of gratitude to Duncan Temple Lang who’s XML package has made it possible to use XML with R for almost 15 years!

```{r}
install.packages("xml2")
```

```{r}
library(xml2)
x <- read_xml("<foo>
  <bar>text <baz id = 'a' /></bar>
  <bar>2</bar>
  <baz id = 'b' />
</foo>")

xml_name(x)
#> [1] "foo"
xml_children(x)
#> {xml_nodeset (3)}
#> [1] <bar>text <baz id="a"/></bar>
#> [2] <bar>2</bar>
#> [3] <baz id="b"/>

# Find all baz nodes anywhere in the document
baz <- xml_find_all(x, ".//baz")
baz
#> {xml_nodeset (2)}
#> [1] <baz id="a"/>
#> [2] <baz id="b"/>
xml_path(baz)
#> [1] "/foo/bar[1]/baz" "/foo/baz"
xml_attr(baz, "id")
#> [1] "a" "b"
```