Graph

graph.js

var Graph = function() {
    this.nodes = {};
    this.edges = {};
    
    this.addNode = function(id, data) {
        this.nodes[id] = data;
    };
    
    this.getNode = function(id) {
        return this.nodes[id] || null;
    };
    
    // tests whether there is an edge from node x to node y.
    this.adjacent = function(x, y) {
        return (this.edges[x] !== undefined && this.edges[x][y] !== undefined ) || null;
    };
    
    // lists all nodes y such that there is an edge from x to y
    this.neighbors = function(x) {
        var neighbors = [];
        if(this.edges[x] !== undefined) {
            for(var neighbor in this.edges[x]) neighbors.push(neighbor);
        }
        return neighbors;
    };
    
    // adds to G the edge from x to y, if it is not there
    this.add = function(x, y) {
        if(this.adjacent(x,y) == null) {
            if(this.edges[x] === undefined) this.edges[x] = {};
            this.edges[x][y] = 0;
            return true;
        }
        return false;
    };
    
    // removes the edge from x to y, if it is there
    this.remove = function(x, y) {
        if(this.edges[x] !== undefined && this.edges[x][y] !== undefined) {
            delete this.edges[x][y];
            return true;
        }
        return false;
    };
    
    // returns the value associated with the node x
    this.getValue = function(x) {
        return this.nodes[x] !== undefined ? this.nodes[x] : null;
    };
        
    // sets the value associated with the node x to a
    this.setValue = function(x, a) {
        this.nodes[i] = data;
    };
        
    // returns the value associated to the edge (x,y)
    this.getEdgeValue = function(x, y) {
        return this.edges[x] !== undefined && this.edges[x][y] !== undefined ? this.edges[x][y] : null;
    };
        
    // sets the value associated to the edge (x,y) to v
    this.setEdgeValue = function(x, y, v) {
        if(this.edges[x] !== undefined && this.edges[x][y] !== undefined) {
            this.edges[x][y] = v;
            return true;
        }
        return false;
    };
};

var graph = new Graph();
graph.addNode('test', {});
graph.addNode('test2', {});
graph.addNode('test3', {});
graph.add('test','test2');
graph.add('test2','test3');
graph.setEdgeValue('test','test2',15);
graph.setEdgeValue('test2','test3',5);