Algo-Web / POData

     *

     * @return ExpandedProjectionNode|null

     */

    private function getCurrentExpandedProjectionNode()

    {

        $expandedProjectionNode = $this->getRequest()->getRootProjectionNode();

        if (null !== $expandedProjectionNode) {

            $names = $this->getStack()->getSegmentNames();

            $depth = count($names);

            if (0 != $depth) {

                for ($i = 1; $i < $depth; ++$i) {

                    $expandedProjectionNode = $expandedProjectionNode->findNode($names[$i]);

                    assert(null !== $expandedProjectionNode, '!is_null($expandedProjectionNode)');

                    assert(

                        $expandedProjectionNode instanceof ExpandedProjectionNode,

                        '$expandedProjectionNode instanceof ExpandedProjectionNode'

                    );

                }

            }

        }

        return $expandedProjectionNode;

    }

    /**

     * Pushes information about the segment whose instance is going to be

     *

     * @return null|RootProjectionNode|ExpandedProjectionNode

     */

    protected function getCurrentExpandedProjectionNode()

    {

        $expandedProjectionNode = $this->getRequest()->getRootProjectionNode();

        if (null === $expandedProjectionNode) {

            return null;

        } else {

            $segmentNames = $this->getStack()->getSegmentNames();

            $depth = count($segmentNames);

            // $depth == 1 means serialization of root entry

            //(the resource identified by resource path) is going on,

            //so control won't get into the below for loop.

            //we will directly return the root node,

            //which is 'ExpandedProjectionNode'

            // for resource identified by resource path.

            if (0 != $depth) {

                for ($i = 1; $i < $depth; ++$i) {

                    $expandedProjectionNode = $expandedProjectionNode->findNode($segmentNames[$i]);

                    assert(null !== $expandedProjectionNode, 'is_null($expandedProjectionNode)');

                    assert(

                        $expandedProjectionNode instanceof ExpandedProjectionNode,

                        '$expandedProjectionNode not instanceof ExpandedProjectionNode'

                    );

                }

            }

        }

        return $expandedProjectionNode;

    }

    /**

     * Builds the string corresponding to query parameters for top level results

     * (result set identified by the resource path) to be put in next page link.