Hi Haris.
In my case the code reported by Tammo (the code normally used to access LimeSurvey) didn't work on the release 5.3 of LimeSurvey.
Looking a bit in detail the implementation of get_session_key reported on github:
github.com/cloudyr/limer/blob/master/R/get_session_key.R
I verified that the problem producing the http 500 error is that the implementation uses the field "admin" in body.json definition, and this field doesn't seem available in versione5.3 (instead it was running in the old version).
Changing the implementation of get_session_key using the field "username", instead, is working:

mm_get_session_key <- function() {
body.json = list(method = "get_session_key",
id = 1,
params = list(username = getOption('lime_username'),
password = getOption('lime_password')))
r <- POST(getOption('lime_api'),
content_type_json(),
body = jsonlite::toJSON(body.json,
auto_unbox = TRUE))
session_key <- as.character(jsonlite::fromJSON(content(r, encoding="utf-8"))$result)
session_cache$session_key <- session_key
return(session_key)
}

Thanks a lot for the info, which actually seems to be specific to the limer implementation.
Looking at the API implementation in application\helpers\remotecontrol\remotecontrol_handle.php, the get_session_key function uses only a username parameter.

The answer is that remotecontrol works correctly with LimeSurvey 5.3.

The solution to my problem was that the requests were not being resolved by the server.  An entry in the hosts file solved the issue.

Sure, but something has changed in Limesurvey, too, because the same code was working in past releases.
I don't know if such a change was documented, but it would be important.

Did you also update your PHP from version 7 to version 8? If so, try loading a fixed limer:
devtools::install_github("Jan-E/limer", force = TRUE)
See my fork of limer at  github.com/Jan-E/limer/ for an explanation. See especially the commit + comment:
[url] github.com/Jan-E/limer/commit/bc807c61fb...376d814e80f126fc796c [/url] 

Please report back if this fixes your problems before I create a pull request for limer.

migliorati wrote:

Sure, but something has changed in Limesurvey, too, because the same code was working in past releases.
I don't know if such a change was documented, but it would be important.
 

Nothing has changed in Limesurvey, but PHP8 is not tolerant for non-existing keys. Probably somewhere in the remotecontrol code PHP8 misses a $username and exits with an error, while PHP7 skips over the error and returns a session_ley to LimeR. Debugging is hard, because the YII framework does not seem to log why the RC2 fails.

Created PR in the limer repo:
github.com/cloudyr/limer/pull/62

Thanks a lot for finding the bug and fixing it. There seems to be no response to that on the main limer branch. My server currently runs on PHP 7.3 and all was fine, but in the future, I will need to use github_install() from devtools to install limer from Jan-E's branch.

See  Please merge PR get_session_key.R: fix PHP 8.1 major flaw #62  now. The PR was finally merged. LimeR is compatible with PHP 7 and PHP 8!

Hi Jane,

I know I'm joining this conversation late, but I'm still hoping for some help or illumination:

I use the R package limer to retrieve survey data via remotecontrol from Limesurvey Cloud. It worked well until early October (must have been LS version 6.2.11 then). Now, running on LS 6.3.6, I get the same error message as reported above when trying to get a session key with get_session_key(): "Error: Argument 'txt' must be a JSON string, URL or file."

I have already tried using your fixed version of limer devtools::install_github("Jan-E/limer", force = TRUE) but this hasn't changed the outcome. I don't know which version of PHP is used by Limesurvey Cloud.

Are others experiencing similar issues? Any thoughts on solutions?

Thanks!
Clemens


 

This is really quite bad, I get the same error and the only change I made was used comfort update. Now LS version is

LimeSurvey Community Edition Version 6.3.6+231120

and my PHP has been 7.4 for a good few months and until this update was working well.

I played around with function from migliorati and came to conclusion that a lot of things work. But it seems that the response coming back from limesurvey might not be JSON? for example you do the usual limer options setup and then:

  body.json = list(method = "get_session_key",
                   id = 1,
                   params = list(username = getOption('lime_username'),
                                 password = getOption('lime_password')))
now you have the json rpc request (I think); then you give that request to httr::POST

POST(getOption('lime_api'),
            content_type_json(),
            body = jsonlite::toJSON(body.json,
                                    auto_unbox = TRUE))
you get a response similar to :Response [ lime.server.yours/index.php/admin/remotecontrol ]
Date: 2023-11-20 19:21
Status: 500
Content-Type: text/html; charset=UTF-8
Size: 20.8 kB
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
" www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns=" www.w3.org/1999/xhtml " xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>ArgumentCountError</title>

<style type="text/css">
/*<![CDATA[*/say instead of printing you save it to an object RRR, then I am sure in RRR$cookies[7] you have your session key

 

Thanks for looking into this, r0bis.

I just experimented with limer / remotecontrol on different LS versions on my server and found that it still works on LS 6.3.4, but the upgrade to LS 6.3.5 (and later) breaks it.

When checking the changelog , I found this issue mentioned for 6.3.4 --> 6.3.5: Fixed issue #19214: JSON RPC response content type should be application/json (#3610) --> see issue described here: bugs.limesurvey.org/view.php?id=19214

If I understand correctly, starting from 6.3.5, the JSON RPC response content type is application/json, while before it was text/javascript. This might break the limer get_session_key() function.

UPDATE: Getting an error message:

When trying to call the remotecontrol API with the limer approach on LS 6.3.5 and later:

the response shows an error message:
Unfortunately, I'm not familiar enough with JSON to figure out how to modify the request so it is valid.
 

Please : report the issue,
community.limesurvey.org/bug-tracker/

Since this breaks a pre-existing system, it's a problem that needs to be solved!