filter on 'Value' column of OData v4 CBS tables

code.R

library(glue)

get_table_odata4 <- function (root=NULL,table="",subtable=NULL,query=NULL,verbose=F,encode=T) {
	if (is.null(subtable)) {
		subtable =""
	} else subtable =glue("/{subtable}")
	if (is.null(root)) 
		root = 	"https://acc-ccb.cbs.nl"
	if (is.null(query)) {
		query =""
	}	else {
			if (encode ==TRUE) {
				query1=URLencode(query)
			} else {
				query1= query
			}
			query1 =glue("&{query1}") 
		}
	url1 = glue("{root}/{table}{subtable}?$format=json{query1}")
	if (verbose==T ) {
		cat(glue("generated url: {url1}"))
		cat(glue("unencoded query:  {query}"))
	}
	get_table_odata4_int(url1)
}

get_table_odata4_int <- function (url1) {
	res1 = httr::GET(url1)
	if (httr::http_error(res1))
		return(httr::http_status(res1)$message)
	else
		return(jsonlite::fromJSON(httr::content(res1,as="text"))$value)
}


q1 = get_table_odata4(table="83765NED",subtable="Observations",
	query = paste0("$filter=(Measure eq 'Gemeentenaam_1') and (IsNumeric ne true) ",
	                        "&$top=5 "),verbose=T)
class(q1)

q2 = get_table_odata4(table="83765NED",subtable="Observations",
	query = paste0("$filter=(Measure eq 'Gemeentenaam_1') and (IsNumeric ne true) and ",
		"contains(Value,'Amstel') "),verbose=T,encode = T)
print(q2)

description.txt

 start UPDATE 27NOV2018:
   updated functions are now available in package HOQCutil ( https://github.com/HanOostdijk/HOQCutil )
   as get_table_cbs_odata4 and get_table_cbs_odata4_GET
 end UPDATE 27NOV2018
 
 start UPDATE 30SEP2018:
  see https://www.linkedin.com/feed/update/urn:li:activity:6439587327596732416
 In his comment on that post Dennis Ramondt answered that 'Value' columns as from now will only be exclusive numeric or exclusive character. 
 end UPDATE 30SEP2018
 
 There is new implementation of (some of) the CBS (Statistics Netherlands) tables.
 This implementation uses Odata v4.
 The actual data is in a subtable 'Observations' that contains a column (field) 'Value'.  
 I would appreciate some help in building a filter on this column.
 Up till now I get 'Server error' messages.
 
 Using table "83765NED" the following filtering works: 
 $filter=(Measure eq 'Gemeentenaam_1') and (IsNumeric ne true) &$top=5  
 The url  https://acc-ccb.cbs.nl/83765NED/Observations?$format=json&$filter=(Measure%20eq%20'Gemeentenaam_1')%20and%20
(IsNumeric%20ne%20true)%20&$top=5%20
returns 5 observations with 6 fields

Expanding the filter to select only records from 'Amstelveen' I tried
$filter=(Measure eq 'Gemeentenaam_1') and (IsNumeric ne true) and contains(Value,'Amstel')
The url https://acc-ccb.cbs.nl/83765NED/Observations?$format=json&$filter=(Measure%20eq%20'Gemeentenaam_1')%20and%20
(IsNumeric%20ne%20true)%20and%20contains(Value,'Amstel')%20
returns "Server error: (500) Internal Server Error"

The R code used can be found in 'code.R' and the version of the packages used in 'sessionInfo.txt'.

sessionInfo.txt

sessionInfo()
R version 3.5.0 (2018-04-23)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] glue_1.3.0

loaded via a namespace (and not attached):
[1] httr_1.3.1     compiler_3.5.0 R6_2.2.2       tools_3.5.0    curl_3.2       yaml_2.2.0     jsonlite_1.5