No HTTP resource was found when use REST API in R

Now I solve this problem, I really appreciate your help

For the convenience for all other guys, here is the correct code .

The mistake I have is httr::POST part

I should declare content_type_json() in the header first

getIdentifier <- function(cred, Identifier, IdentifierType){
  uri1 <- "https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch"

  part1 <- c('{"Request": {"Identifier": "')
  part2 <- c('","IdentifierType": "')
  part3 <- c('", "Range": {
             "Start": "2015-11-17T00:00:00.000Z",
             "End": "2015-11-24T00:00:00.000Z"}}}')
  token1 <- paste("Token", cred[2], sep = " ")
  request <- paste(part1, Identifier, part2, IdentifierType, part3, sep = "")
  a <- httr::POST(uri1, body = request,
                 add_headers(Prefer = "respond-async",Authorization = token1),
                 content_type_json())
  result <- httr::content(a, "parsed", "application/json")
  return(result)
}

All comments

@Yarch , please refer to the developer guide here

On page number 39th, the uri is correct but it is a HTTP POST method.

But your code seems to use a GET method (httr::GET) ? Please confirm.

Thank you for point this out, actually I tried both method. If I use httr:POST I will obtain a different error message

$error
$error$message
[1] "The request contains an entity body but no Content-Type header. The inferred media type 'application/octet-stream' is not supported for this resource."

I appreciate your apply, hope to see your feedback soon

@Yarch

This error means that you have not defined Content-Type in your http request header.

Please follow the sample request from the developer guide.

The Content-Type is "application/json"

Here is the detailed information I observed, I hope it could be helpful regarding on this issue

Starting from variable "a", my output is incorrect

Here is the output of a

Response [https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch] 
Date: 2017-09-27 00:20
Status: 404
Content-Type: application/json; charset=utf-8
Size: 157 B

Based on this description, I think the issue is related to the uri i'm using

And for the The Content-Type you just mention in previous reply, I think I set up the correct format.

For your information, here is another example I write in R, which works fine

getUserInfo <- function(cred){
part1 <- "https://hosted.datascopeapi.reuters.com/RestApi/v1/Users/Users("
part2 <- ")"
uri1 <- paste(part1, cred[1], part2, sep = "")
token1 <- paste("Token", cred[2], sep = " ")
a <- httr::GET(uri1, add_headers(Prefer = "respond-async", Authorization = token1))
result <- httr::content(a, "parsed", "application/json") 
return(result)
}

@Yarch

I just did 3 tests on the API calls:

1. POST method following the sample request from developer guide

Request:

POST https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch HTTP/1.1
Prefer: respond-async
Content-Type: application/json
Authorization: Token <mytoken>
Cache-Control: no-cache

{
  "Request": {
    "Identifier": "US4592001014",
    "IdentifierType": "Isin",
    "Range": {
      "Start": "2008-01-01T00:00:00.000Z",
      "End": "2008-01-01T00:00:00.000Z"
    }
  }
}

Response:

HTTP/1.1 200 OK
Cache-Control: no-cache
Content-Type: application/json; charset=utf-8

@{"@odata.context":"https://hosted.datascopeapi.reuters.com/RestApi/v1/$metadata#Collection(ThomsonReuters.Dss.Api.Search.HistoricalSearchResult)","value":[{"Identifier":"IBM","IdentifierType":"Ric","Source":"","Key":"VjF8MHgzMDAwMDAwMDAwMDAwMDAwfDB4MzAwMDAwMDAwMDAwMDAwMHx8fHx8fHxJQk18","Description":"Historical Instrument","InstrumentType":"Unknown","Status":"Valid","DomainCode":"6","FirstDate":"1996-01-02T00:00:00.000Z","LastDate":"2017-09-26T00:00:00.000Z","History":[]},...<a lot of entries here>...}

2. POST method with incorrect Content-Type header

Request:

POST https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch HTTP/1.1
cache-control: no-cache
Prefer: respond-async
Content-Type: application/octet-stream
Authorization: Token <mytoken>

{
  "Request": {
    "Identifier": "US4592001014",
    "IdentifierType": "Isin",
    "Range": {
      "Start": "2008-01-01T00:00:00.000Z",
      "End": "2008-01-01T00:00:00.000Z"
    }
  }
}

Response:

HTTP/1.1 415 Unsupported Media Type
Cache-Control: no-cache
Content-Length: 118
Content-Type: application/json; charset=utf-8

{"error":{"message":"The request entity's media type 'application/octet-stream' is not supported for this resource."}}

3. GET method

Request:

GET https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch HTTP/1.1
cache-control: no-cache
Prefer: respond-async
Content-Type: application/json
Authorization: Token <mytoken>

Please note that HTTP GET method cannot contain body.

Response:

HTTP/1.1 404 Not Found
Cache-Control: no-cache
Content-Type: application/json; charset=utf-8

{"error":{"message":"No HTTP resource was found that matches the request URI 'https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch'."}}

I do not put all the detail headers here, just only related headers to troubleshoot the issue.

Hope this is more clear now.

Please refer to page 38th on the developer guide.

From the sample Request, this API call does not require Content-Type nor body.

So it is working as expected.

Thanks for your clarification. It makes sense. And I notice that the 3rd example you provide has the identical error that I have

So maybe I need to declare this Content type at the beginning of my code.

Yes you are right. Thanks for this clarification

Now I solve this problem, I really appreciate your help

For the convenience for all other guys, here is the correct code .

The mistake I have is httr::POST part

I should declare content_type_json() in the header first

getIdentifier <- function(cred, Identifier, IdentifierType){
  uri1 <- "https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch"

  part1 <- c('{"Request": {"Identifier": "')
  part2 <- c('","IdentifierType": "')
  part3 <- c('", "Range": {
             "Start": "2015-11-17T00:00:00.000Z",
             "End": "2015-11-24T00:00:00.000Z"}}}')
  token1 <- paste("Token", cred[2], sep = " ")
  request <- paste(part1, Identifier, part2, IdentifierType, part3, sep = "")
  a <- httr::POST(uri1, body = request,
                 add_headers(Prefer = "respond-async",Authorization = token1),
                 content_type_json())
  result <- httr::content(a, "parsed", "application/json")
  return(result)
}