Nanograph

Minimalistic in-memory graph for metadata management. Allows to create directions graphs to store entities and connect them. Connections, called "edges" may also contain data.

Installation

Just run npm i nanograph. Types for Typescript are provided and must not be installed separately.

Usage

Initialisation

import { Nanograph } from 'nanograph';

const nano: Nanograph = new Nanograph();

Insert vertices and edges

const { _id: vertex1Id, error: error1 } = nano.createVertex('PERSON', { name: 'John Doe' });
const { _id: vertex2Id, error: error2 } = nano.createVertex('PERSON', { name: 'Jane Doe' });

const { _id: friendshipId } = nano.createEdge('FRIENDSHIP', vertex1Id, vertex2Id, {
    type: 'platonic', since: Date.now(),
});

Retrieve vertices and edges

Retrieve the first edge matching provided criteria. If an ID is given, it can simply be passed as string.

const vertex = nano.findVertices('PERSON', vertex1Id ).getFirst();			
const edge = nano.findEdges('FRIENDSHIP', { _id: { equals: friendshipId } }).getFirst();

For filtering, instead of an id, parameters can be provided. For this version, only equals is possible. Result of getAll is a list of vertices or edges

const vertex = nano.findVertices('PERSON', { name: { equals: 'John Doe' } }).getAll();
const edges = nano.findEdges('FRIENDSHIP', { type: { equals: 'platonic' } }).getAll();

Traversal is also possible using labels and properties to filter

const vertices = nano
    .findVertices('PERSON', { name: { equals: 'John Doe' } }) // a person called John Doe
    .over('CHILDOF').to('PERSON') // searching for John Does Parents
    .over('CHILDOF').to('PERSON', { gender: { equals: 'm' } }) // searching for their father, John Doe's grandfather
    .over('MARRIED').to('PERSON') // searching for his wife, John Doe's grandmother
    .getAll();

Update Entities

Both edges and vertices can be updated using update methods. Old values will be kept. If a value to update is already exiting, it will be overwritten.

nano.updateVertex(vertexId, { weight: 6000, hasFur: false });
nano.updateEdge(edgeId, { isShareHolder: true, holdings: 15 });

Delete Entities

Vertices and edges can be deleted by their id.

nano.deleteEdge(edgeId);
nano.deleteVertex(vertexid);