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question

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Accepted
45 5 14 12

Detect securities unknown to Reuters

When requesting data for a security through its ISIN over the DSS REST API, I find out very late that actually that security is "not in the dictionary". This happens only through a bad error that I trap when trying to get the row.DynamicProperties.Item(<field name>). It suddenly tells me that the row object is not defined anymore !

But the real reason can be found by using the exception's InnerException.GetBaseException.Message, which says: "The given key was not present in the dictionary."

Isn't there a "faster" way for me to find out about that, right after getting the result of my request ? A kind of status of the request's result ?

dss-rest-apidssdatascope-selectrest-apiextraction
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@bernard.thouin, could you please post the data request you made, with the incriminated ISIN ? That will help the community to investigate.

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13.7k 26 8 12

@bernard.thouin, this is why I like Postman, it delivers the result of a call without any treatment, ideal for an investigation. Running a Ratings Extraction request for ISIN GB00BDXG0P01 delivers the following response body, which explains the issue:

 {
    "@odata.context": "https://hosted.datascopeapi.reuters.com/RestApi/v1/$metadata#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.ExtractionResult",
    "Contents": [
        {
            "IdentifierType": "Isin",
            "Identifier": "GB00BDXG0P01",
            "Error": "Not found"
        }
    ],
    "Notes": [
        "All identifiers were invalid.  No extraction performed."
    ]
}
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Upvotes
45 5 14 12

Hi Christiaan

Here my request:

extractionRequest = New RatingsExtractionRequest With {.IdentifierList = instrumentList, .ContentFieldNames = fieldNames,

.Condition = New RatingsCondition With {

.RatingLevel = New RatingLevel With {.IsIssue = True, .IsIssuer = False},

.DaysAgo = 7,

.ReportDateRangeType = ReportDateRangeType.Last,

.IncludeInstrumentsWithNoRatings = True,

.RatingSourcesCodes = ratingCodes}}

With:

  • Identifier list for security with ISIN GB00BDXG0P01, Ident. type Isin
  • Filed list starting with ISIN, then Asset ID. Actually irrelevant, as the error occurs on the first field, the ISIN

The code than triggers the error is this:

' Extract value

sValue = row.DynamicProperties.Item(extractionRequest.ContentFieldNames.Item(i))

which normally returns data, but for that ISIN, it trggers an error "row is not defined", but the catch section of the Try surrounding the whole processing of the request's result gets this:

Catch ex As Exception

ex.Message = "The given key was not present in the dictionary."

I have quite a bit of code before that, which "decodes" what's in the result rows, but I get no error until that point. The result shows me 1 row with 12 fields, which is what I requested, I can decode the row.Identifier and the row.IdentifierType, the first field name using

extractionRequest.ContentFieldNames.Item(0)

but then the whole thing bombs on the retrieval of the row.DynamicProperties of the first field.

HTH

Bernard

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11.3k 25 8 14
@bernard.thouin

It seems that the ISIN GB00BDXG0P01 is not valid, so the result doesn't contain any data including the ISIN field. As result, the "ISIN" key is not available in the dictionary, and then cause the error when you try to access the field directly.

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Upvotes
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Ah yes, seeing your "Error" label, I discovered I could test on row.Error for the value "Not found", and therefore trap theses non-existing ISINs as the first thing to do when processing each result row. That works fine :)

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