Feature: Aggregate over Arrays / via ArrayDataSource

Greetings,

is it possible to accept ArrayDataSource|array as another type in \Contributte\Datagrid\AggregationFunction\IAggregationFunction::processDataSource() ?

Then to \Contributte\Datagrid\DataSource\ArrayDataSource something like following:

	public function processAggregation(IAggregationFunction $function): void
	{
		$function->processDataSource($this);
	}

And then into \Contributte\Datagrid\AggregationFunction\FunctionSum::processDataSource following part:

		if ( $dataSource instanceof ArrayDataSource) {
			foreach( $dataSource->getData() as $item )
				$this->result += $item[$this->column];
		}

		if ( is_array($dataSource)) {
			foreach( $dataSource as $item )
				$this->result += $item[$this->column];
		}

Use case:

Due sheer completness of dataset we cannot access the data from it directly via SQL, so we pre-calculate it in parts and then use it with aggregation. That makes us dependent on arrays / ArrayDataSource. And due limitation of other parts of Datagrid we must store its affected files locally and overwrite them on deploy.

Do you want PR? Discuss.

Thanks.

Start by reading IAggregationFunction::processDataSource(), DataSource/ArrayDataSource, and AggregationFunction/FunctionSum, which are the entry points named in the issue. Trace how aggregation currently receives data and identify the related implementations that need to accept arrays or ArrayDataSource. Done means aggregation can process both inputs for the stated pre-calculated dataset use case.