df_to_xml {xmlconvert}

Converting XML to data frames and vice versa

Description

Converts dataframes to XML documents.

Usage

df_to_xml(
  df,
  fields = "tags",
  record.tag = "record",
  field.names = NULL,
  only.fields = NULL,
  exclude.fields = NULL,
  root.node = "root",
  xml.file = NULL,
  non.exist = NULL,
  encoding = "UTF-8",
  no.return = FALSE
)

Arguments

df

Dataframe to be converted to XML

fields

A character value, either "tags" or "attributes". Specifies whether the fields of each data record will be represented in the resulting XML document by XML tags or by attributes. See the Details section of df_to_xml() for more on this topic. Default is "tags"

record.tag

Name of the tags that will represent the data records in the resulting XML (i.e. each record has one element with this tag name).

field.names

Names of the fields in the XML file. If NULL then the variable names from the dataframe are used. Field names are corrected automatically to comply with XML naming requirements.

only.fields

Optional vector variable names from the dataframe that will be included in the XML document. If NULL then all fields from the dataframe are included in the XML document.

exclude.fields

Optional vector of variable names from the dataframe that will not be included in the XML document.

root.node

A character value with the desired name of the root element of the XML document; "root" by default.

xml.file

Name of a file the XML document it written to. If NULL no file will be created.

non.exist

Value that will be written into the XML document as field value in case the respective element in the dataframe is NA. If NULL, which is the default, no XML tag/attribute (depennding on the fields argument) will be created for this dataframe element. Using a non-NULL value for non-exist allows to make sure that each data record tag in the XML document has exactly the same structure even if some values may be empty (because they are NA in the original data)

encoding

Encoding of the XML document; default is "UTF-8"

no.return

Logical option to prevent df_to_xml() from returning the XML document it creates; use this if you are only interested in saving the XML document to a file using the xml.file argument.

Value

The resulting XML document that be edited with the functions from the xml2 package. There is no return value if the no.return argument is set to TRUE.

See Also

Other xmlconvert: xml_to_df()

Examples

# Create a dataframe
soccer.worldcups <- data.frame(list(year=c(2014, 2010, 2006),
    location=c("Brazil", "South Africa", "Germany"),
    goals_scored=c(171, 145, 147),
    average_goals=c(2.7, 2.3, 2.4),
    average_attendance=c(57918, 49669,52491)),
    stringsAsFactors = FALSE)

# Convert to XML with the fields (i.e. dataframe variables/columns) stored in XML tags
xml <- df_to_xml(soccer.worldcups, fields="tags", record.tag = "worldcup")

# Convert to XML with the fields (i.e. dataframe variables/columns) stored in attributes
xml <- df_to_xml(soccer.worldcups, fields="tags", record.tag = "worldcup")