stagger.js

var db = require('./../db')

function getPaths(startnode, endnode,
numpaths, maxdepth,
graphs,
allowcycles,
onresult, onfinish)
{
	var results = [];
	var depth = 1;
	
	function buildQuery()
	{
		if(results.length < numpaths && depth <= maxdepth)
		{
			//START portion
			var query = "START a = node( {a} ), b = node( {b} )";
			
			//MATCH portion
			query += " MATCH p=(a)-->";
			for( var i = 1; i < depth; ++i )
			{
				query += "()-->";
			}
			query += "(b)";
			
			//WHERE Clause
			var where = [];
			//If cycles should be limited, filter paths
			if(allowcycles == false){
				where.push(" ALL(n in nodes(p) where 1=length(filter(m in nodes(p) : m=n)))");
			}
			
			if(graphs.length > 0){
				var comparison = ""
				for(var i = 0; i < graphs.length; ++i){
					if(i != 0) { comparison += " OR "}
					comparison += "n.graphid! = " + graphs[i];
				}
				
				where.push( "ALL(n in nodes(p) where " + comparison + ")" )
			}
			
			if( where.length > 0 )
			{
				query += " WHERE"
				query += where.join(" AND ")
			}
			
			//RETURN portion
			query += " RETURN p"
			
			//Limit
			query += " LIMIT " + (numpaths - results.length)
			
			
			
			//Params
			params = {}
			params.a = startnode
			params.b = endnode
			
			console.log(query);
			
			db.graphdb.query( query, params, function(err, result){
				depth += 1;
				
				results = results.concat(result);
				
				if(onresult != null && result != null && result.length > 0)
				{
					result.forEach( function(item, i, array)
					{
						onresult(item);
					});
				}
				
				buildQuery();
			});
		}
		else
		{
			if(onfinish != null)
			{
				onfinish(results);
			}
		}
	}
	
	buildQuery();
}

exports.getPaths = getPaths;

/* Example

getPaths(13077, //Starting node id
35038, //Ending node id
1000, //Amount of pathways to return
10, //Maximum depth to explore
[1], //Array of ids for each graph that can be traversed
false, //Don't allow cycles
function(result)
{
	//Print pathways as they are streamed in
	//console.log(result);
},
function(results)
{
	//Print total number of pathways returned
	console.log(results.length + " pathways returned.");
})
*/