Basic JS Graph

basicGraph.js

#!/usr/bin/env node

/* Creates a simple property graph using the adjacency-list strategy, based on
   https://www.khanacademy.org/computing/computer-science/algorithms/graph-representation/a/representing-graphs
*/

var nodes = [
        { id: 0, label: 'Top' }
      , { id: 1, label: 'Bottom Right' }
      , { id: 2, label: 'Bottom Left' }
    ]

  , graph = [
        [ [1, { label: 'STEP_1' }] ]
      , [ [2, { label: 'STEP_2' }], [0, { label: 'START_OVER' }] ]
      , [ [0, { label: 'FINISHED' }], [1, { label: 'UNDO' }] ]
    ]
;

function getNode(id) {
    var node;

    if (nodes[id]) {
        node = nodes[id];
    }

    return node;
}

function getRelations(id) {
    var relations = [];

    if (nodes[id]) {
        var node = getNode(id);

        for (var j=0; j<graph[id].length; j++) {
            relations.push(graph[id][j]);
        }
    }

    return relations;
}

function showRelationsForNode(id) {
    var node = getNode(id)
      , relations = getRelations(id)
    ;

    for (var i=0; i<relations.length; i++) {
        var relatedNode = getNode(relations[i][0])
          , relation = relations[i][1]
        ;

        console.log('(n1:`%s`)-[r:`%s`]->(n2:`%s`)', node.label, relation.label, relatedNode.label);
    }
}

showRelationsForNode(0);
showRelationsForNode(1);
showRelationsForNode(2);

/* OUTPUTS:

$ node test.js
(n1:`Top`)-[r:`STEP_1`]->(n2:`Bottom Right`)
(n1:`Bottom Right`)-[r:`STEP_2`]->(n2:`Bottom Left`)
(n1:`Bottom Right`)-[r:`START_OVER`]->(n2:`Top`)
(n1:`Bottom Left`)-[r:`FINISHED`]->(n2:`Top`)
(n1:`Bottom Left`)-[r:`UNDO`]->(n2:`Bottom Right`)
*/