/// <summary>
/// Unmarshaller the response from the service to the response class.
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override AmazonWebServiceResponse Unmarshall(JsonUnmarshallerContext context)
{
DetectEntitiesResponse response = new DetectEntitiesResponse();
context.Read();
int targetDepth = context.CurrentDepth;
while (context.ReadAtDepth(targetDepth))
{
if (context.TestExpression("Entities", targetDepth))
{
var unmarshaller = new ListUnmarshaller <Entity, EntityUnmarshaller>(EntityUnmarshaller.Instance);
response.Entities = unmarshaller.Unmarshall(context);
continue;
}
if (context.TestExpression("PaginationToken", targetDepth))
{
var unmarshaller = StringUnmarshaller.Instance;
response.PaginationToken = unmarshaller.Unmarshall(context);
continue;
}
if (context.TestExpression("UnmappedAttributes", targetDepth))
{
var unmarshaller = new ListUnmarshaller <UnmappedAttribute, UnmappedAttributeUnmarshaller>(UnmappedAttributeUnmarshaller.Instance);
response.UnmappedAttributes = unmarshaller.Unmarshall(context);
continue;
}
}
return(response);
}
private async Task <string> GetComprehendData(string transcriptText, string key)
{
JObject transcriptJSON = JObject.Parse(transcriptText);
string test = (string)transcriptJSON["Text"];
AmazonComprehendClient client = new AmazonComprehendClient();
DetectEntitiesRequest entitiesRequest = new DetectEntitiesRequest();
entitiesRequest.LanguageCode = LanguageCode.En;
entitiesRequest.Text = test;
DetectSentimentRequest sentimentRequest = new DetectSentimentRequest();
sentimentRequest.LanguageCode = LanguageCode.En;
sentimentRequest.Text = test;
DetectKeyPhrasesRequest keyPhrasesRequest = new DetectKeyPhrasesRequest();
keyPhrasesRequest.LanguageCode = LanguageCode.En;
keyPhrasesRequest.Text = test;
DetectEntitiesResponse entitiesResponse = await client.DetectEntitiesAsync(entitiesRequest);
DetectSentimentResponse setimentResponse = await client.DetectSentimentAsync(sentimentRequest);
DetectKeyPhrasesResponse keyPhrasesResponse = await client.DetectKeyPhrasesAsync(keyPhrasesRequest);
CreateKeyPhraseCSV(key, keyPhrasesResponse);
CreateSetimentJSON(key, setimentResponse);
//now send the file to s3
//we need to write two different files, one for setiment and one for Key Phrases.
return(string.Empty);
}
/// <summary>
/// A function for responding to S3 create events. It uses Amazon Comprehend to detect entities, sentiment
/// and save them to S3.
/// </summary>
/// <param name="s3Event"></param>
/// <param name="context"></param>
/// <returns></returns>
public async Task FunctionHandler(S3Event s3Event, ILambdaContext context)
{
foreach (var record in s3Event.Records)
{
var detectEntitiesResponse = new DetectEntitiesResponse();
var detectSentimentResponse = new DetectSentimentResponse();
try
{
using (GetObjectResponse response = await _s3Client.GetObjectAsync(new GetObjectRequest()
{
BucketName = record.S3.Bucket.Name,
Key = record.S3.Object.Key
}))
{
using (StreamReader reader = new StreamReader(response.ResponseStream))
{
string text = await reader.ReadToEndAsync();
//
// Detect entities
//
try
{
detectEntitiesResponse = await _comprehendClient.DetectEntitiesAsync(new DetectEntitiesRequest
{
LanguageCode = LanguageCode.En,
Text = text
});
}
catch (AmazonComprehendException ex)
{
context.Logger.LogLine("Error in detecting entities.");
context.Logger.LogLine(ex.Message);
return;
}
//
// Detect sentiment
//
try
{
detectSentimentResponse = await _comprehendClient.DetectSentimentAsync(new DetectSentimentRequest
{
LanguageCode = LanguageCode.En,
Text = text
});
}
catch (AmazonComprehendException ex)
{
context.Logger.LogLine("Error in detecting sentiment.");
context.Logger.LogLine(ex.Message);
return;
}
}
}
}
catch (AmazonS3Exception ex)
{
context.Logger.LogLine(ex.Message);
}
//
// save detections in S3 bucket
//
try
{
var body = new TextDetail()
{
Id = Guid.NewGuid().ToString(),
Entities = detectEntitiesResponse.Entities,
Sentiment = detectSentimentResponse.Sentiment
};
await _s3Client.PutObjectAsync(new PutObjectRequest()
{
ContentBody = JsonConvert.SerializeObject(body),
BucketName = TARGET_BUCKET,
Key = Path.Combine("texts", Path.GetFileNameWithoutExtension(record.S3.Object.Key), "detections.json")
});
}
catch (AmazonS3Exception ex)
{
context.Logger.LogLine(ex.Message);
}
}
}
