NAME

ArangoDB2::Traversal - ArangoDB traversal API methods

DESCRIPTION

API METHODS

execute

POST /_api/traversal

Perform traversal. Returns API response.

PROPERTY METHODS

direction

Direction for traversal. If set, must be either "outbound", "inbound", or "any. If not set, the expander attribute must be specified

edgeCollection

(optional) name of the collection that contains the edges.

expander

body (JavaScript) code of custom expander function must be set if direction attribute is not set function signature: (config, vertex, path) -> array expander must return an array

filter

(optional, default is to include all nodes): body (JavaScript code) of custom filter function function signature: (config, vertex, path) -> mixed can return four different string values:

"exclude" -> this vertex will not be visited.

"prune" -> the edges of this vertex will not be followed.

"" or undefined -> visit the vertex and follow it's edges.

Array -> containing any combination of the above. If there is at least one "exclude" or "prune" respectivly is contained, it's effect will occur.

graphName

(optional) name of the graph that contains the edges. Either edgeCollection or graphName has to be given. In case both values are set the graphName is prefered.

init

body (JavaScript) code of custom result initialisation function function signature: (config, result) -> void initialise any values in result with what is required

itemOrder

(optional): item iteration order can be "forward" or "backward"

maxDepth

(optional, ANDed with any existing filters): visits only nodes in at most the given depth

maxIterations

(optional): Maximum number of iterations in each traversal. This number can be set to prevent endless loops in traversal of cyclic graphs. When a traversal performs as many iterations as the maxIterations value, the traversal will abort with an error. If maxIterations is not set, a server-defined value may be used.

minDepth

(optional, ANDed with any existing filters): visits only nodes in at least the given depth

order

(optional): traversal order can be "preorder" or "postorder"

sort

(optional): body (JavaScript) code of a custom comparison function for the edges. The signature of this function is (l, r) -> integer (where l and r are edges) and must return -1 if l is smaller than, +1 if l is greater than, and 0 if l and r are equal. The reason for this is the following: The order of edges returned for a certain vertex is undefined. This is because there is no natural order of edges for a vertex with multiple connected edges. To explicitly define the order in which edges on the vertex are followed, you can specify an edge comparator function with this attribute. Note that the value here has to be a string to conform to the JSON standard, which in turn is parsed as function body on the server side. Furthermore note that this attribute is only used for the standard expanders. If you use your custom expander you have to do the sorting yourself within the expander code.

startVertex

id of the startVertex, e.g. "users/foo". You can pass either string or an ArangoDB2 object with an id attribute.

strategy

(optional): traversal strategy can be "depthfirst" or "breadthfirst"

uniqueness

(optional): specifies uniqueness for vertices and edges visited if set, must be an object like this: "uniqueness": {"vertices": "none"|"global"|path", "edges": "none"|"global"|"path"}

visitor

(optional): body (JavaScript) code of custom visitor function function signature: (config, result, vertex, path) -> void visitor function can do anything, but its return value is ignored. To populate a result, use the result variable by reference

AUTHOR

Ersun Warncke, <ersun.warncke at outlook.com>

http://ersun.warnckes.com

COPYRIGHT

Copyright (C) 2014 Ersun Warncke

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.