Graph functions

---------------

The ArangoDB PHP driver provided PHP wrapper methods for common graph functions

that were implemented server-side. When one of these wrapper methods was called,

the PHP driver assembled an AQL query that called the equivalent graph AQL functions

on the server. The driver has provided some extra post-filtering options for some

of the graph functions, but for others it only provided a subset of the features

available server-side.

With ArangoDB 3.0, the graph functionality on the server-side has changed: the

previously available AQL graph functions that were called by the PHP driver are

not available anymore in 3.0. This affects the following previously existing

methods of the PHP driver's `GraphHandler` class, which are now gone in 3.0:

- GraphHandler::getNeighborVertices($graph, $vertexExample, $options = array())

- GraphHandler::getConnectedEdges($graph, $vertexId, $options = array())

- GraphHandler::getVertices($graph, $options = array())

- GraphHandler::getEdges($graph, $options = array())

- GraphHandler::getPaths($graph, $options = array())

- GraphHandler::getShortestPaths($graph, $startVertexExample = array(), $endVertexExample = array(), $options = array())

- GraphHandler::getDistanceTo($graph, $startVertexExample = null, $endVertexExample = null, $options = array())

- GraphHandler::getCommonNeighborVertices($graph, $vertex1Example = null, $vertex2Example = null, $options1 = array(),$options2 = array())

- GraphHandler::getCommonProperties($graph, $vertex1Example= null, $vertex2Example = null, $options = array())

- GraphHandler::getAbsoluteEccentricity($graph, $vertexExample = null, $options = array())

- GraphHandler::getEccentricity($graph, $options = array())

- GraphHandler::getAbsoluteCloseness($graph, $vertexExample = null, $options = array())

- GraphHandler::getCloseness($graph, $options = array())

- GraphHandler::getAbsoluteBetweenness($graph, $options = array())

- GraphHandler::getBetweenness($graph, $options = array())

- GraphHandler::getRadius($graph, $options = array())

- GraphHandler::getDiameter($graph, $options = array())

Most of these methods can be emulated by issuing an AQL query from the PHP driver.

AQL provides provides blocks for computing the vertices, connected edges, and paths

in a graph or just dedicated collections. As a bonus, by using AQL queries one is

not limited to the subset of the functionality that was available in the "old"

graph functions' interfaces, but can use the full functionality and composability

of AQL.

/**

const ENTRY_DATABASE_USERS = 'users';

$payload = array(self::ENTRY_DATABASE_NAME => $name,

self::ENTRY_DATABASE_USERS => array(

array(

"username" => $connection->getOption(ConnectionOptions::OPTION_AUTH_USER),

"passwd" => $connection->getOption(ConnectionOptions::OPTION_AUTH_PASSWD)

)

));

{

return self::databases($connection);

}

/**

public static function databases(Connection $connection)