Manipulating edges

graph.edgeCollection

graph.edgeCollection(collectionName): GraphEdgeCollection

Returns a new GraphEdgeCollection instance with the given name bound to this graph.

Arguments

• collectionName: string

  Name of the edge collection.

Examples

const db = new Database();
// assuming the collections "edges" and "vertices" exist
const graph = db.graph("some-graph");
const collection = graph.edgeCollection("edges");
assert.equal(collection.name, "edges");
// collection is a GraphEdgeCollection

graph.addEdgeDefinition

async graph.addEdgeDefinition(definition): Object

Adds the given edge definition definition to the graph.

Arguments

• definition: Object

  For more information on edge definitions see the HTTP API for managing graphs.

Examples

const db = new Database();
// assuming the collections "edges" and "vertices" exist
const graph = db.graph('some-graph');
await graph.addEdgeDefinition({
  collection: 'edges',
  from: ['vertices'],
  to: ['vertices']
});
// the edge definition has been added to the graph

graph.replaceEdgeDefinition

async graph.replaceEdgeDefinition(collectionName, definition): Object

Replaces the edge definition for the edge collection named collectionName with the given definition.

Arguments

• collectionName: string

  Name of the edge collection to replace the definition of.

• definition: Object

  For more information on edge definitions see the HTTP API for managing graphs.

Examples

const db = new Database();
// assuming the collections "edges", "vertices" and "more-vertices" exist
const graph = db.graph('some-graph');
await graph.replaceEdgeDefinition('edges', {
  collection: 'edges',
  from: ['vertices'],
  to: ['more-vertices']
});
// the edge definition has been modified

graph.removeEdgeDefinition

async graph.removeEdgeDefinition(definitionName, [dropCollection]): Object

Removes the edge definition with the given definitionName form the graph.

Arguments

• definitionName: string

  Name of the edge definition to remove from the graph.

• dropCollection: boolean (optional)

  If set to true, the edge collection associated with the definition will also be deleted from the database.

Examples

const db = new Database();
const graph = db.graph('some-graph');

await graph.removeEdgeDefinition('edges')
// the edge definition has been removed

// -- or --

await graph.removeEdgeDefinition('edges', true)
// the edge definition has been removed
// and the edge collection "edges" has been dropped
// this may have been a bad idea

graph.traversal

async graph.traversal(startVertex, opts): Object

Performs a traversal starting from the given startVertex and following edges contained in any of the edge collections of this graph.

Arguments

• startVertex: string

  The handle of the start vertex. This can be either the _id of a document in the graph or a document (i.e. an object with an _id property).

• opts: Object

  See the HTTP API documentation for details on the additional arguments.

  Please note that while opts.filter, opts.visitor, opts.init, opts.expander and opts.sort should be strings evaluating to well-formed JavaScript functions, it’s not possible to pass in JavaScript functions directly because the functions need to be evaluated on the server and will be transmitted in plain text.

Examples

const db = new Database();
const graph = db.graph('some-graph');
const collection = graph.edgeCollection('edges');
await collection.import([
  ['_key', '_from', '_to'],
  ['x', 'vertices/a', 'vertices/b'],
  ['y', 'vertices/b', 'vertices/c'],
  ['z', 'vertices/c', 'vertices/d']
])
const result = await graph.traversal('vertices/a', {
  direction: 'outbound',
  visitor: 'result.vertices.push(vertex._key);',
  init: 'result.vertices = [];'
});
assert.deepEqual(result.vertices, ['a', 'b', 'c', 'd']);