private static async Task CalculateSentimentAsync(FeedbackDbContext dbContext)
{
// NOTE: Cognetive services accepts up to 1000 "documents" at a time.
var feedbackBatch = dbContext.Feedbacks.Where(f => !f.SentimentScore.HasValue).Take(1000).ToList();
if (feedbackBatch.Any())
{
Console.WriteLine("Found feedback to analyze...");
var documents = feedbackBatch.Select(f => new TextDocument(f.Id, f.Content));
var request = new TextAnalysisRequest(documents);
var response = await TextAnalyzer.CalculateSentimentAsync(request);
foreach (var sentiment in response.Documents)
{
var feedback = feedbackBatch.Single(f => f.Id == sentiment.Id);
feedback.SentimentScore = sentiment.Score;
}
await dbContext.SaveChangesAsync();
await CalculateSentimentAsync(dbContext); // Recursively process until we are done.
}
else
{
Console.WriteLine("Did not find feedback to analyze.");
}
}
public static async Task <TextAnalysisResponse> CalculateSentimentAsync(TextAnalysisRequest request)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(BaseUrl);
// Request headers.
client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", AccountKey);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
// Request body must be JSON format.
var requestJson = JsonConvert.SerializeObject(request);
// Detect sentiment via API call.
var uri = "text/analytics/v2.0/sentiment";
var response = await CallEndpointAsync(client, uri, requestJson);
Console.WriteLine("\nDetect sentiment response:\n" + response);
// Response body also comes back in JSON format.
return(JsonConvert.DeserializeObject <TextAnalysisResponse>(response));
}
}