Fail to preserve Date object

[renkun-ken]

If a column of a data frame is Date or POSIXct or POSIXlt-class vector, they will be printed as integers in the column.

library(DT)
datatable(data.frame(date = seq(as.Date("2015-01-01"), by = "day", length.out = 5), x = 1:5))

will produce a DataTable like

date    x
16436   1
16437   2
16438   3
16439   4
16440   5

The same thing does not happen with knitr::kable:

> knitr::kable(data.frame(date = seq(as.Date("2015-01-01"), by = "day", length.out = 5), x = 1:5))


|date       |  x|
|:----------|--:|
|2015-01-01 |  1|
|2015-01-02 |  2|
|2015-01-03 |  3|
|2015-01-04 |  4|
|2015-01-05 |  5|

[yihui]

That is a problem of RJSONIO. Sigh. It seems every single problem of RJSONIO has been well solved in jsonlite, but we are just stuck in RJSONIO:

> x = data.frame(date = seq(as.Date("2015-01-01"), by = "day", length.out = 5), x = 1:5)
> RJSONIO::toJSON(x)
[1] "{\n \"date\": [ 16436, 16437, 16438, 16439, 16440 ],\n\"x\": [ 1, 2, 3, 4, 5 ] \n}"
> jsonlite::toJSON(x)
[{"date":"2015-01-01","x":1},{"date":"2015-01-02","x":2},{"date":"2015-01-03","x":3},{"date":"2015-01-04","x":4},{"date":"2015-01-05","x":5}] 

[juancentro]

@yihui are you in the middle of solving this? I just installed the latest DT and when a DT has date columns it doesn't print anything
datatable(data.frame(x = Sys.Date()))

[jcheng5]

duncantl/RJSONIO#3

:(

[yihui]

Should be "fixed" now. Thanks!

[renkun-ken]

Appreciate your work! Will try it out.