[R] help with json data from the web into data frame in R

[K. Elo]

Hi!

Seems to be an encoding problem. This worked for me (have not full-
checked the output, though):

fromJSON(encodeString(zWebObj))

HTH,
Kimmo

2018-05-08 12:49 -0700, David Winsemius wrote:
> > 
> > On May 8, 2018, at 10:08 AM, Evans, Richard K. (GRC-H000) <richard.
> > k.evans using nasa.gov> wrote:
> > 
> > Hi David,  .. I think I've got it :-) 
> > Please let me know if you see anything glaringly wrong with this:
> > 
> > library(RCurl)
> > zWebObj <- postForm("https://www.semantic-mediawiki.org/w/api.php",
> >   "action" = "ask",
> >   "query" = "[[Category:City]]|?Capital%20of|?Has%20area",
> >   "format" = "json"
> >   .opts = list(ssl.verifypeer = FALSE)
> > )
> > 
> The R interpreter tells me there's a missing comma after the line: 
> 
> "format" = "json"
> 
> Fixing that syntactic error I get:
> 
> str(zWebObj)
> # ---bein console output
>  atomic [1:1]
> {"query":{"printrequests":[{"label":"","key":"","redi":"","typeid":"_
> wpg","mode":2}],"results":{"File:2166320938 | __truncated__
>  - attr(*, "Content-Type")= Named chr [1:2] "application/json" "utf-
> 8"
>   ..- attr(*, "names")= chr [1:2] "" "charset"
> #--- end console output-----
> js1 <-fromJSON(zWebObj)
> #--------
> Error: lexical error: inside a string, '\' occurs before a character
> which it may not.
>           title":""}},"serializer":"SMW\Serializers\QueryResultSerial
> i
>                      (right here) ------^
> 
> 
> I'm not really a JSON expert, so am not equipped to offer debugging
> assistance there.
> 
> -- 
> David.
> 
> 
> > 
> > Thank you!
> > -Rich
> > 
> > -----Original Message-----
> > From: R-help [mailto:r-help-bounces using r-project.org] On Behalf Of
> > Evans, Richard K. (GRC-H000)
> > Sent: Tuesday, May 08, 2018 12:51 PM
> > To: David Winsemius
> > Cc: r-help using r-project.org
> > Subject: Re: [R] help with json data from the web into data frame
> > in R
> > 
> > [non-tabular json data] -- ok.. so I think I need to figure out how
> > to make it tabular. Thanks!
> > 
> > [curl] -- I was hoping there was a cleaner way to do it.. using R
> > to evoke cURL to get the data as text and then passing it into
> > getJSON seems to be what I need to do.
> > 
> > Do you by chance have an simple example of using RCurl to get a
> > response ignoring cert errors?
> > 
> > ty
> > -Rich
> > 
> > -----Original Message-----
> > From: David Winsemius [mailto:dwinsemius using comcast.net] 
> > Sent: Tuesday, May 08, 2018 12:25 PM
> > To: Evans, Richard K. (GRC-H000)
> > Cc: r-help using r-project.org
> > Subject: Re: [R] help with json data from the web into data frame
> > in R
> > 
> > 
> > > 
> > > On May 8, 2018, at 9:03 AM, Evans, Richard K. (GRC-H000) <richard
> > > .k.evans using nasa.gov> wrote:
> > > 
> > > That said, I have two issues to ask for help with:
> > > 
> > > 1) how to ignore cert errors with a fromJSON call
> > If you can do it with curl, then why aren't you doing one of a) a
> > system call, b) installing and loading RCurl, c) installing and
> > loading curl (the R package with that name)?
> > 
> > > 
> > > 
> > > And 
> > > 
> > > 2) why the json data from the example link doesn't convert to a
> > > data frame.
> > That was already answered in my earlier response. It's not a
> > tabular result, so it doesn't "fit" into a tabular structure.
> >