Graph Example

by scotp71

HTML

<input type="button" onclick="createGraph();" value="Create Graph" />
<br/>
<br/> Select two nodes:
<br />From
<select id="from"></select>
To
<select id="to"></select>
<input type="button" onclick="calculate();" value="Calculate" />
<br/>
<p id="nodes"></p>
<br/>
<p id="edges"></p>
<br/>
<br/><span id="result" />

JavaScript

// This is a basic implementation of a Graph
// It has nodes and edges 
// I am using a stack (array in Javascript) to hold info

var Node = function(_name) {
  this.name = _name;
  this.discovered = false;
  this.edges = [];
  return this;
}

var Edge = function(_from, _to, _cost) {
  this.from = _from;
  this.to = _to;
  this.cost = _cost;
  return this;
}

var Graph = function() {

  // This is a specific implementation of a graph
  // that uses nodes edges and paths. There are many
  // more ways to implement a graph and you should 
  // research them

  this.nodes = [];
  this.edges = [];
  this.paths = [];

  this.addNode = function(_name) {
    var node = new Node(_name);
    this.nodes.push(node);
    return node;
  };

  this.addEdge = function(_from, _to, _cost) {
    var edge1 = new Edge(_from, _to, _cost);
    var edge2 = new Edge(_from, _to, _cost);
    
    this.edges.push(edge1);
    
    _from.edges.push(edge1);
    _to.edges.push(edge2);

    return edge1;
  };

  this.printNodes = function() {
    var s = "All Nodes in Graph <br/>";
    for (var i = 0; i < this.nodes.length; i++) {
      s = s + "Node: " + i + "   Name: " + this.nodes[i].name + "</br>";
    }
    return s;
  }

  this.printEdges = function() {
    var s = "All Edges in Graph <br/>";
    for (var i = 0; i < this.edges.length; i++) {
      s += "Edge: " + i + "   From: " + this.edges[i].from.name + "   To: " + this.edges[i].to.name + "   Cost: " + this.edges[i].cost + "</br>";
    }
    return s;
  }
  
  this.depthFirstSearch = function(_from){
  	this.reset();
    var nodeFrom = this.getNodeByName(_from);
    return this.DFS(nodeFrom);
  }
  
  this.breadthFirstSearch = function(_from){
  	this.reset();
    var nodeFrom = this.getNodeByName(_from);
    var q = nodeFrom;
    return this.BFS(q);
  }
  
  this.getNodeByName = function(_name){
  	for(var i=0; i<this.nodes.length; i++){
    	if(this.nodes[i].name == _name) return this.nodes[i];
    }
    return null;
  }
  
 ...