POST request using HTTR - r

Question

I am trying to request data using the httr package. Following this format:
args <- list(metrics = c(list(name = "Jobs.2018",as = "Jobs 2018")),
constraints = list(dimensionName ="Area",
map = list("Latah County ID" = c(16057))))
test <- POST(url =
"https://agnitio.emsicloud.com/emsi.us.demographics/2018.3",
add_headers(`authorization` = paste("bearer",token)),
add_headers(`content-type` ="application/json"),
body = toJSON(args,auto_unbox = TRUE),
verbose())
I keep getting a 400 Bad Request error with everything I have looked up and tried. Do I need to add something to the arguments that I am just not finding?
P.S. I am sorry that this isn't a repeatable example

Answer 1

We'll assume (a bad thing but necessary for an answer) that you obtained token by issuing a prior POST request as indicated on the linked API page and then properly decoded the JSON web token into token.
If you did that properly, then one next likely possibility is malformed body data in POST request.
When I look at a sample API call:
curl --request POST \
--url https://agnitio.emsicloud.com/emsi.us.industry/2018.3 \
--header 'authorization: bearer <access_token>' \
--header 'content-type: application/json' \
--data '{ "metrics": [ { "name": "Jobs.2017", "as":"2017 Jobs" }, { "name": "Establishments.2017" } ], "constraints": [ { "dimensionName": "Area", "map": { "Latah County, ID": ["16057"] } }, { "dimensionName": "Industry", "map": { "Full Service Restaurant s": ["722511"] } } ] }'
that sample JSON looks like this pretty-printed:
{
"metrics": [
{
"name": "Jobs.2017",
"as": "2017 Jobs"
},
{
"name": "Establishments.2017"
}
],
"constraints": [
{
"dimensionName": "Area",
"map": {
"Latah County, ID": [
"16057"
]
}
},
{
"dimensionName": "Industry",
"map": {
"Full Service Restaurants": [
"722511"
]
}
}
]
}
Yours looks like:
{
"metrics": {
"name": "Jobs.2018",
"as": "Jobs 2018"
},
"constraints": {
"dimensionName": "Area",
"map": {
"Latah County ID": 16057
}
}
}
when it needs to look more like this:
{
"metrics": [
{
"name": "Jobs.2018",
"as": "Jobs 2018"
}
],
"constraints": [
{
"dimensionName": "Area",
"map": {
"Latah County ID": [
"16057"
]
}
}
]
}
To do that, we need to use this list structure:
list(
metrics = list(
list(
name = jsonlite::unbox("Jobs.2018"),
as = jsonlite::unbox("Jobs 2018")
)),
constraints = list(list(
dimensionName = jsonlite::unbox("Area"),
map = list("Latah County ID" = c("16057"))
))
) -> args
Note especially that the API expects that map ID JSON data element to be character and not integer/numeric.
Now, we can make the POST request like this (spaced out for answer readability as it has embedded comments):
httr::POST(
url = "https://agnitio.emsicloud.com/emsi.us.demographics/2018.3",
httr::add_headers(
`authorization` = sprintf("bearer %s", token)
),
encode = "json", # this lets' httr do the work for you
httr::content_type_json(), # easier than making a header yourself
body = args,
httr::verbose()
) -> res
That should work but b/c it's a closed API without free registration I cannot test it.