Spreadsheet::getContent

protected function getContent()
{
	if(!$this->isLoaded())
	{
		return null;
	}
	$result = $columnNames = [];
	$columns = SpreadsheetTable::getList(['filter' => ['FIELD_ID' => $this->getFieldId()]])->fetchAll();
	if($columns)
	{
		foreach($columns as $column)
		{
			$columnNames[] = $column['ENTITY_NAME'];
		}
	}
	foreach($this->data as $index => $provider)
	{
		$result['DATA'][$index] = [];
		foreach($columnNames as $columnName)
		{
			/** @var DataProvider $provider */
			$result['DATA'][$index][] = $provider->getValue($columnName);
		}
	}
}