json: JSON (JavaScript Object Notation) generation

In Rpad: Workbook-style, web-based interface to R

Description

Write out a JSON structure of an R object.

Usage

  json(x,...)

Arguments

x	an object to convert to JSON.
...	unused for now.

Details

JSON is Javascript Object Notation, a data-exchange format especially suited for passing to Javascript. Mapping from S to Javascript is as follows:

list (including data frames and other list objects) -> object character -> string array -> array array with names -> object matrix -> 2-D array numeric -> number NULL -> null TRUE -> true FALSE -> false NA -> NaN

Other types are converted to character using as.character and output as character arrays or objects. Handling of NA's is problematic as Javascript doesn't have NA's. Strings are escaped. Currently, dimensioning in higher dimension arrays is lost. Object attributes are also ignored.

Value

A character string of class json. With automatic printing, the string is sent to the output (with cat).

Author(s)

Tom Short, EPRI, ([e-mail])

See Also

See also http://www.json.org/

Examples

json( 1:10 )
## [1,2,3,4,5,6,7,8,9,10]

json( c("apple", "line\nwith break") )
## ["apple","line\nwith break"]

json( c(a = 1, b = 5, c = 10) )
## {"a":1,"b":5,"c":10} 

json( data.frame(a = 1:5, b = 6:10) )
## {"a":[1,2,3,4,5],"b":[6,7,8,9,10]}

json( list(a = 5, b = 1:10, c = data.frame(a = 1:2, b = 3:4)) )
## {"a":5,"b":[1,2,3,4,5,6,7,8,9,10],"c":{"a":[1,2],"b":[3,4]}}

Rpad documentation built on May 2, 2019, 4:43 p.m.