NAME

Neo4j::Driver::Type::Path - Directed sequence of relationships between two nodes

VERSION

version 0.19

SYNOPSIS

 $q = "MATCH p=(a:Person)-[k:KNOWS]->(b:Person) RETURN p";
 $path = $driver->session->run($q)->list->[0]->get('p');
 
 ($node_a, $node_b) = $path->nodes;
 ($relationship_k)  = $path->relationships;
 
 ($a, $k, $b) = $path->elements;

DESCRIPTION

A path is a directed sequence of relationships between two nodes. Its direction may be separate from that of the relationships traversed.

It is allowed to be of length 0, meaning there are no relationships in it. In this case, it contains only a single node which is both the start and the end of the path.

METHODS

Neo4j::Driver::Type::Path implements the following methods.

elements

 @all = $path->elements;

Return the path as a list alternating between nodes and relationships in path sequence order.

nodes

 @nodes = $path->nodes;

Return all nodes of this path.

The start node of this path is the first node in the array this method returns, the end node is the last one.

 @nodes = $path->nodes;
 $start_node = $nodes[0];
 $end_node   = $nodes[@nodes - 1];

relationships

 @rels = $path->relationships;

Return all relationships of this path.

The length of a path is defined as the number of relationships.

 @rels = $path->relationships;
 $length = scalar @rels;

EXPERIMENTAL FEATURES

Neo4j::Driver::Type::Path implements the following experimental features. These are subject to unannounced modification or removal in future versions. Expect your code to break if you depend upon these features.

Calling in scalar context

 $all   = $path->elements;  # fails
 $nodes = $path->nodes;  # fails
 $rels  = $path->relationships;  # fails

The elements(), nodes(), and relationships() methods die if called in scalar context.

BUGS

When paths are returned via HTTP, the objects accessible via elements(), nodes(), and relationships() lack meta data for their labels and types. This is due to an issue in the Neo4j server.

SEE ALSO

AUTHOR

Arne Johannessen <ajnn@cpan.org>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2016-2021 by Arne Johannessen.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)