read xml file

read xml file

Usage

read_xml(
  xml,
  pointer = TRUE,
  escapes = FALSE,
  declaration = FALSE,
  whitespace = TRUE,
  empty_tags = FALSE,
  skip_control = TRUE,
  comments = FALSE
)

Arguments

xml

something to read character string or file

pointer

should a pointer be returned?

escapes

bool if characters like "&" should be escaped. The default is no escapes. Assuming that the input already provides valid information.

declaration

should the declaration be imported

whitespace

should whitespace pcdata be imported

empty_tags

should <b/> or <b></b> be returned

skip_control

should whitespace character be exported

comments

should comments be parsed (1) or only comments returned (2)

Details

Read xml files or strings to pointer and checks if the input is valid XML. If the input is read into a character object, it will be reevaluated every time it is called. A pointer is evaluated once, but lives only for the lifetime of the R session or once it is gc().

Examples

  # a pointer
  x <- read_xml("<a><b/></a>")
  print(x)
#> <a>
#>  <b />
#> </a>
  print(x, raw = TRUE)
#> <a><b/></a>
  str(x)
#> Class 'pugi_xml' <externalptr> 
#>  - attr(*, "escapes")= logi FALSE
#>  - attr(*, "empty_tags")= logi FALSE
#>  - attr(*, "skip_control")= logi TRUE

  # a character
  y <- read_xml("<a><b/></a>", pointer = FALSE)
  print(y)
#> [1] "<a><b/></a>"
  print(y, raw = TRUE)
#> [1] "<a><b/></a>"
  str(y)
#>  chr "<a><b/></a>"

  # Errors if the import was unsuccessful
  try(z <- read_xml("<a><b/>"))
#> Error : xml import unsuccessful

  xml <- '<?xml test="yay" ?><a>A & B</a>'
  # difference in escapes
  read_xml(xml, escapes = TRUE, pointer = FALSE)
#> [1] "<a>A &amp; B</a>"
  read_xml(xml, escapes = FALSE, pointer = FALSE)
#> [1] "<a>A & B</a>"
  read_xml(xml, escapes = TRUE)
#> <a>A &amp; B</a>
  read_xml(xml, escapes = FALSE)
#> <a>A & B</a>

  # read declaration
  read_xml(xml, declaration = TRUE)
#> <?xml test="yay"?>
#> <a>A & B</a>