Batch generation

Aspose.OMR for .NET can automatically generate multiple personalized OMR forms, for example exam sheets for individual students. Bulk-generation is available through Aspose.OMR.BatchProcessings.BatchOmrEngine API.

Personalized values used for bulk form generation is provided through Aspose.OMR.BatchProcessings.DataSet collection. The number of generated forms is equal to the number of Aspose.OMR.BatchProcessings.DataRecord entries in the instance of Aspose.OMR.BatchProcessings.DataSet class:

var dataSet = new DataSet();
// Add first student
var record1 = new DataRecord("JohnDoe");
record1.Fields.Add("student_name", "John Doe");
dataSet.Records.Add(record1);
// Add first student
var record2 = new DataRecord("JohnDoe");
record2.Fields.Add("student_name", "Jane Doe");
dataSet.Records.Add(record2);

Use ${value ID} placeholder in text or JSON markup to insert the field with the given ID from the DataRecord element into the designated position in the form:

?text=${student_name}
	font_style=bold
?empty_line=
?answer_sheet=Answers
	columns_count=3
	elements_count=15
	answers_count=5

There are two ways to bulk-generate forms. The easiest one is to use the Generate method of BatchOmrEngine class. This approach is recommended for generating a small number of forms (less than 100):

// Initialize Aspose.OMR API
BatchOmrEngine batchEngine = new BatchOmrEngine();
// Define the type, size and position of the form identifier barcode
GlobalPageSettings settings = new GlobalPageSettings();
BarcodeConfig batchBarcode = new BarcodeConfig();
batchBarcode.BarcodeType = BarcodeType.QR;
batchBarcode.X = 500;
batchBarcode.Y = 500;
settings.BatchBarcode = batchBarcode;
// Bulk generate forms
BatchGenerationResult generationResult = batchEngine.Generate(dataSet, "source.txt", settings);
generationResult.Save("generated-templates", "recognition_pattern.domr");

The saved results consist of several files:

• Printable forms as images or PDF documents.
• A recognition pattern used by Aspose.OMR recognition engine, in a special .DOMR format. This file is required for mapping optical marks to form elements and is necessary for recognizing filled forms!

If you want to generate a very large number of forms, it is recommended to use Aspose.OMR.BatchProcessings.TemplateExporter class which handles advanced bulk generation and allows to iterate through generated form pages:

// Initialize Aspose.OMR API
BatchOmrEngine batchEngine = new BatchOmrEngine();
// Define the type, size and position of the form identifier barcode
GlobalPageSettings settings = new GlobalPageSettings();
BarcodeConfig batchBarcode = new BarcodeConfig();
batchBarcode.BarcodeType = BarcodeType.QR;
batchBarcode.X = 500;
batchBarcode.Y = 500;
settings.BatchBarcode = batchBarcode;
// Bulk generate forms
BatchGenerationResult generationResult = batchEngine.Generate(dataSet, "source.txt", settings);
// Iterate through generated forms
FormExporter exporter = generationResult.getFormExporter();
while (exporter.MoveToNextForm())
{
	// Save a form to PDF
	using (var memoryStream = new MemoryStream())
	{
		exporter.ExportFormPdf(memoryStream);
	}
	// Save individual form pages to images
	while (exporter.MoveToNextPage())
	{		
		using (var memoryStream = new MemoryStream())
		{
			exporter.ExportPagePng(stream);
		}
	}
}
// Save recognition pattern
using (var memoryStream = new MemoryStream())
{
	exporter.ExportRecognitionPattern(memoryStream);
}