Connection Scan Algorithm for JavaScript


State:

* basic csa without footpaths is functional

* merger that combines different streams of connections is functional

The Connection Scan Algorithm (CSA) for Javascript takes a stream of "connections" and transforms it into a stream of solutions to get from a certain stop to a certain stop. The algorithm will find the earliest arrival times first, and will return alternatives as long as the stream runs.

Use it

You can install the library using npm:

``bash
npm install csa
`

And include it in your nodejs application
`javascript
var csa = require('csa');
var planner = new csa.BasicCSA({departureStop: "...", arrivalStop: "...",departureTime:new Date()});
connectionsReadStream.pipe(planner);
planner.on("result", function (result) {
console.log("Path found:",result);
connectionsReadStream.close();
});
planner.on("data", function (connection) {
//Access to a minimum spanning tree of connections being built up
//May be useful for e.g., creating isochrone maps
});
`

Multiple connection streams

Instead of using one stream of connections, you can combine multiple streams as input by using MergeStream
`javascript
var connectionsStreams = [
[ 'stream1', connectionsReadStream1 ],
[ 'stream2', connectionsReadStream2 ],
...
];

var connectionsReadStream = new csa.MergeStream(connectionsStreams, query.departureTime);
`

You can add streams by setting an eventlistener on the MergeStream instance.
To remove a stream, just end the stream itself.
`javascript
connectionsReadStream.on("data", function (connection) {
connectionsReadStream.addConnectionsStream('newStream', newConnectionsReadStream);
});
``

_Protip: you can use browserify on this repo to use CSA in the browser_