getDocumentAnalysis method

Future<GetDocumentAnalysisResponse> getDocumentAnalysis({ required String jobId, int? maxResults, String? nextToken, })

Gets the results for an Amazon Textract asynchronous operation that analyzes text in a document.

You start asynchronous text analysis by calling StartDocumentAnalysis, which returns a job identifier (JobId). When the text analysis 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 StartDocumentAnalysis. 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 GetDocumentAnalysis, and pass the job identifier (JobId) from the initial call to StartDocumentAnalysis.

GetDocumentAnalysis returns an array of Block objects. The following types of information are returned:

• Form data (key-value pairs). The related information is returned in two Block objects, each of type KEY_VALUE_SET: a KEY Block object and a VALUE Block object. For example, Name: Ana Silva Carolina contains a key and value. Name: is the key. Ana Silva Carolina is the value.
• Table and table cell data. A TABLE Block object contains information about a detected table. A CELL Block object is returned for each cell in a table.
• Lines and words of text. A LINE Block object contains one or more WORD Block objects. All lines and words that are detected in the document are returned (including text that doesn't have a relationship with the value of the StartDocumentAnalysis FeatureTypes input parameter).

Selection elements such as check boxes and option buttons (radio buttons) can be detected in form data and in tables. A SELECTION_ELEMENT Block object contains information about a selection element, including the selection status.

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 GetDocumentAnalysis, and populate the NextToken request parameter with the token value that's returned from the previous call to GetDocumentAnalysis.

For more information, see Document Text Analysis.

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 StartDocumentAnalysis. A JobId value is only valid for 7 days.

Parameter maxResults : The maximum number of results to return per paginated call. The largest value that 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<GetDocumentAnalysisResponse> getDocumentAnalysis({
  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.GetDocumentAnalysis'
  };
  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 GetDocumentAnalysisResponse.fromJson(jsonResponse.body);
}