node-pgrouting

A simple interface to pgRouting.

Features:

• Multi-cost
• Filters
• Aggregation of identical sections based on its properties
• Multi-snapping
• routing AND isocurve

How to use ?

Routing

const pgr = require("node-pgrouting")(conf);
let geojeson_results = await pgr.routing({from:"46,1",to:"47,2","type":"duration", "avoid":"toll"});

• The routing return a Promise, so you can use the async/await like above or the Promise itself.
• type and avoid depend on data structure (see Data structure)

Isocurve

const pgr = require("node-pgrouting")(conf);
let geojeson_results = await pgr.isocurve({from:"46,1","type":"duration", "avoid":"toll", "values":"3600,7200"});

• The isocurve return a Promise, so you can use the async/await like above or the Promise itself.
• type and avoid depend on data structure (see Data structure)
• from or to

Capabilities (data structure)

const pgr = require("node-pgrouting")(conf);
let types = await pgr.getTypes();

• The getTypes return a Promise, so you can use the async/await like above or the Promise itself.
• types is an array of available cost based on data structure (see Data structure)

const pgr = require("node-pgrouting")(conf);
let filters = await pgr.getFilters();

• The getFilters return a Promise, so you can use the async/await like above or the Promise itself.
• filters is an array of available filter based on data structure (see Data structure)

const pgr = require("node-pgrouting")(conf);
let properties = await pgr.getProperties();

• The getProperties return a Promise, so you can use the async/await like above or the Promise itself.
• properties is an array of available feature properties based on data structure (see Data structure)

PgRouting version

const pgr = require("node-pgrouting")(conf);
let version = await pgr.pgVersion();

• The pgVersion return a Promise, so you can use the async/await like above or the Promise itself.
• pgVersion is the version of PgRouting extension, not PosGIS or Postgresql version.

Close connection to the database

const pgr = require("node-pgrouting")(conf);
...your stuff...
pgr.close();

Configuration

The conf object let you configure the connection to the database and some routing options :

• Connection parameters: node-pgrouting use pg as an interface to PostgreSQL database, with the conf object as parameters like host, port, user, password and database. You can use same environment variables as libpq too : see pg documentation for more details.
• table: : table that contains the network. You can use the environment variable PGTABLE too. table can contain a schema. (Default: edge)
• maxSnappingDistance: when process the routing, node-pgrouting needs to connect your start and end point to closest edge of the network within maxSnappingDistance meters.
• snappingRatio: allow to snap not only the nearest point but also all near points with a distance difference lower than snappingRatio (=(distance-min(distance))/min(distance)). (Default: 0 (no ratio)).

Data structure

Requirements: pgRouting concepts.

The data structure determine the routing capabilites. Some attributes are reserved:

• id: an uniq identifier of the network section
• source, target: for pgRouting topology
• cost_TYPE and reverse_cost_TYPE: the cost of the section when perform routing to minimize TYPE. You can provides as many type as wanted.
• filter_FILTER: true to avoid this section by use avoid: 'FILTER' in routing params. You can provides as many filter as wanted.
• the_geom: geometry of the section, with 4326 SRID.
• seq: use in routing response.

All other properties are used to identify the section. If multiple sections have the same properties, they are grouped in the routing response.

Example:

id	name	source	target	cost_distance	reverse_cost_distance	cost_duration	reverse_cost_duration	cost_consumption	reverse_cost_consumption	filter_toll	cost	filter_highway
10693	D86	65	66	397.550220811875	397.550220811875	20.4454399274679	20.4454399274679	0.0238530132487125	0.0238530132487125	f	Free	f
7711	A1/E15-E19	6497	6914	3369.1892947396	3369.1892947396	101.075678842188	101.075678842188	0.303227036526564	0.303227036526564	t	Paying	t
11326	A10	71	72	702.986479543753	702.986479543753	21.0895943863126	21.0895943863126	0.0632687831589378	0.0632687831589378	f	Free	t
7885	D3	45	46	1238.94362175843	1238.94362175843	49.557744870337	49.557744870337	0.0867260535230898	0.0867260535230898	f	Free	f
7663	D317	6819	6872	5334.01082992236	5334.01082992236	274.320556967436	274.320556967436	0.320040649795342	0.320040649795342	f	Free	f
7799	N104	6789	46	3921.77709540926	3921.77709540926	117.653312862278	117.653312862278	0.352959938586834	0.352959938586834	f	Free	f

This table provides:

• 3 types: distance, duration, consumption
• 2 filters: toll, highway
• 2 properties: name, cost

Demonstration/Development

1. Start demo/dev environmnent

bash dev/up.sh

2. Use the GUI or the REST service:

• http://127.0.0.1:8080, graphical interface : use the right click to define start and end point.
• http://127.0.0.1:8080/app/version
• http://127.0.0.1:8080/app/capabilities
• http://127.0.0.1:8080/app/route?from=46,1&to=47,2&type=duration&avoid=toll

3. Perform unit tests:

docker exec -i -t pgr_node_1 grunt test

4. Cleanup Dev env

bash dev/down.sh