getDocumentTextDetection method

Future<GetDocumentTextDetectionResponse> getDocumentTextDetection({ required String jobId, int? maxResults, String? nextToken, })

Gets the results for an Amazon Textract asynchronous operation that detects text in a document. Amazon Textract can detect lines of text and the words that make up a line of text.

You start asynchronous text detection by calling StartDocumentTextDetection, which returns a job identifier (JobId). When the text detection operation finishes, Amazon Textract publishes a completion status to the Amazon Simple Notification Service (Amazon SNS) topic that's registered in the initial call to StartDocumentTextDetection. To get the results of the text-detection operation, first check that the status value published to the Amazon SNS topic is SUCCEEDED. If so, call GetDocumentTextDetection, and pass the job identifier (JobId) from the initial call to StartDocumentTextDetection.

GetDocumentTextDetection returns an array of Block objects.

Each document page has as an associated Block of type PAGE. Each PAGE Block object is the parent of LINE Block objects that represent the lines of detected text on a page. A LINE Block object is a parent for each word that makes up the line. Words are represented by Block objects of type WORD.

Use the MaxResults parameter to limit the number of blocks that are returned. If there are more results than specified in MaxResults, the value of NextToken in the operation response contains a pagination token for getting the next set of results. To get the next page of results, call GetDocumentTextDetection, and populate the NextToken request parameter with the token value that's returned from the previous call to GetDocumentTextDetection.

For more information, see Document Text Detection.

May throw InvalidParameterException. May throw AccessDeniedException. May throw ProvisionedThroughputExceededException. May throw InvalidJobIdException. May throw InternalServerError. May throw ThrottlingException. May throw InvalidS3ObjectException.

Parameter jobId : A unique identifier for the text detection job. The JobId is returned from StartDocumentTextDetection. A JobId value is only valid for 7 days.

Parameter maxResults : The maximum number of results to return per paginated call. The largest value you can specify is 1,000. If you specify a value greater than 1,000, a maximum of 1,000 results is returned. The default value is 1,000.

Parameter nextToken : If the previous response was incomplete (because there are more blocks to retrieve), Amazon Textract returns a pagination token in the response. You can use this pagination token to retrieve the next set of blocks.

Implementation

Future<GetDocumentTextDetectionResponse> getDocumentTextDetection({
  required String jobId,
  int? maxResults,
  String? nextToken,
}) async {
  ArgumentError.checkNotNull(jobId, 'jobId');
  _s.validateStringLength(
    'jobId',
    jobId,
    1,
    64,
    isRequired: true,
  );
  _s.validateNumRange(
    'maxResults',
    maxResults,
    1,
    1152921504606846976,
  );
  _s.validateStringLength(
    'nextToken',
    nextToken,
    1,
    255,
  );
  final headers = <String, String>{
    'Content-Type': 'application/x-amz-json-1.1',
    'X-Amz-Target': 'Textract.GetDocumentTextDetection'
  };
  final jsonResponse = await _protocol.send(
    method: 'POST',
    requestUri: '/',
    exceptionFnMap: _exceptionFns,
    // TODO queryParams
    headers: headers,
    payload: {
      'JobId': jobId,
      if (maxResults != null) 'MaxResults': maxResults,
      if (nextToken != null) 'NextToken': nextToken,
    },
  );

  return GetDocumentTextDetectionResponse.fromJson(jsonResponse.body);
}