| Version: | 0.2.23 |
| Title: | JSON for R |
| Author: | Alex Couture-Beil [aut, cre] |
| Maintainer: | Alex Couture-Beil <rjson_pkg@mofo.ca> |
| Depends: | R (≥ 4.0.0) |
| Description: | Converts R object into JSON objects and vice-versa. |
| URL: | https://github.com/alexcb/rjson |
| License: | GPL-2 |
| Repository: | CRAN |
| Packaged: | 2024-09-16 17:34:28 UTC; root |
| NeedsCompilation: | yes |
| Date/Publication: | 2024-09-16 18:20:02 UTC |
JSON for R
Description
JSON (JavaScript Object Notation) is a lightweight data-interchange format. This package converts JSON objects into R objects and vice-versa. See json.org for an overview of JSON. Unicode is unfortunately not supported at the moment.
Convert JSON To R
Description
Convert a JSON object into an R object.
Usage
fromJSON( json_str, file, method = "C", unexpected.escape = "error", simplify = TRUE )Arguments
json_str |
a JSON object to convert |
file |
the name of a file to read the json_str from; this can also be a URL. Only one of json_str or file must be supplied. |
method |
use the |
unexpected.escape |
changed handling of unexpected escaped characters. Handling value should be one of "error", "skip", or "keep"; on unexpected characters issue an |
simplify |
If TRUE, attempt to convert json-encoded lists into vectors where appropriate. If FALSE, all json-encoded lists will be wrapped in a list even if they are all of the same data type. |
Value
R object that corresponds to the JSON object
See Also
Examples
fromJSON('[1,2,3]', simplify=TRUE)
# returns c(1,2,3)
fromJSON('[1,2,3]', simplify=FALSE)
# returns list(1,2,3)
#As a result, this will output "1"
toJSON(fromJSON('[1]', simplify=TRUE))
#Compared with this which will output "[1]" as expected
toJSON(fromJSON('[1]', simplify=FALSE))
#R vs C execution time
x <- toJSON( iris )
system.time( y <- fromJSON(x) )
system.time( y2 <- fromJSON(x,method = "R") )
Convert buffered JSON objects To R
Description
Convert a collection of JSON objects into R objects.
Usage
newJSONParser(method = "R")Arguments
method |
use the |
Value
A list of functions used for parsing objects
See Also
Examples
sample_json <- '
{
"breakfast" : [ "milk", "fruit loops", "juice" ],
"lunch" : [ "left over sushi" ]
}
'
parser <- newJSONParser()
parser$addData( sample_json )
food <- parser$getObject()
print( food )
#This is equivalent to using FromJSON( sample_json )
#However, sample_json can be split into several parts:
### EXAMPLE 2:
part_1 <- '{ "breakfast" : [ "milk", "fruit loops", "juice" ], '
part_2 <- '"lunch" : [ "left over sushi" ]'
# close off the first object, and create a 2nd JSON object, which is simply an
# array
part_3 <- '} [1,2,3,4,5]'
parser <- newJSONParser()
parser$addData( part_1 )
parser$getObject() #returns NULL - since part_1 isn't complete
parser$addData( part_2 )
parser$getObject() #returns NULL - since part_2 still isn't complete
parser$addData( part_3 )
parser$getObject() #returns the first food object
parser$getObject() #returns the second array
Convert R To JSON
Description
Convert an R object into a corresponding JSON object.
***Lists with unnamed components are not currently supported***
Usage
toJSON( x, indent=0, method="C" )Arguments
x |
a vector or list to convert into a JSON object |
indent |
an integer specifying how much indentation to use when formatting the JSON object; if 0, no pretty-formatting is used |
method |
use the |
Value
a string containing the JSON object
See Also
Examples
x <- list( alpha = 1:5, beta = "Bravo",
gamma = list(a=1:3, b=NULL),
delta = c(TRUE, FALSE) )
json <- toJSON( x )
fromJSON( json )
#named vectors are treated as JSON objects (lists)
toJSON(islands[1:4])
#data.frames must be converted into a list before converting into JSON
plot(cars, pch=2)
json_cars <- toJSON(as.list(cars))
points( data.frame( fromJSON( json_cars ) ), col="red", pch=3 )
#special R types are encoded as strings
testString <- c(1,2,3,4,NA,NaN,Inf,8,9);
toJSON(testString);