This repository contains the implementation of an JSON-LD API for greenhouses or gardens following the RESTful principles. The server, that exposes the API and is implemented in Node.js, represents a board in which sensors and actuators are connected and used for real-time monitoring and status setting. Furthermore the server is able to provide RESTdesc descriptions useful to represent the functionalities of the available services.
Currently the board is simulated. This means there are fake sensors, actuators, plants and geolocation coodiantes.
It's possible adding or removing sensors, actuators and plants, modifying the /lib/fakeResources.json file.
As you can see, it is composed by three parts:
- sensors, that contains a list of sensors;
- actuators, that contains a list of actuators;
- plants, that contains a list of plants.
Types of permitted sensors:
- TemperatureSensor;
- MoistureSensor;
- LightSensor.
Types of permitted actuators:
- IrrigationPump;
- PowerWindow;
- Heater.
The coordinates are statically written in the code. To change them, modify the /lib/Location_class.js file.
After having cloned the repository, you have to install the Node.js modules with npm install.
Now you can run the server through node index.js. The default host is 127.0.0.1 and the default port is 3300. You can change this configuration, setting the two environment variables HOST and PORT.
The following table summarises the RESTful services which are currently implemented. Each of them returns a JSON-LD response whose context is stored in /public/contexts/ directory.
| URL | Method Type | Service Description |
|---|---|---|
| /sensors | GET | Get sensors' list |
| /sensors/:sensorID | GET | Get information about a sensor |
| /actuators | GET | Get actuators' list |
| /actuators/:actuatorID | GET | Get information about a actuator |
| /actuators/:actuatorID/:newState | PUT | Update the actuator state |
| /plants | GET | Get plants' list |
| /plants/:plantID | GET | Get information about a plant |
| /geo | GET | Get board's coordinates |
In order to describe the functionalities of the available services and let machines know what a service does (and enable machines to generate plans to combine services by different sources), each service has its correspondent RESTdesc description.
The RESTdesc descriptions are stored in /public/RESTdesc_descriptions/board directory.
To get a RESTdesc description for a service, you have to invoke the correspondent HTTP OPTIONS.
For example, if you want the RESTdesc description of the /sensors/:sensorID URL, you have to do this:
curl -i -X OPTIONS http://127.0.0.1:3300/sensors/1
The response will be like this:
HTTP/1.1 200 OK
X-Powered-By: Express
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET,PUT,POST,DELETE,OPTIONS
Access-Control-Allow-Headers: Content-Type, Authorization, Content-Length, X-Requested-With
Content-Type: text/n3; charset=utf-8
Content-Length: 519
ETag: W/"207-52b7d12c"
Date: Wed, 13 May 2015 13:07:01 GMT
Connection: keep-alive
@prefix vocab: <http://www.example.org/vocab#>.
@prefix http: <http://www.w3.org/2011/http#>.
@prefix dbpedia: <http://dbpedia.org/resource/>.
@prefix iot: <https://iotdb.org/pub/iot#>.
{
?sensor a vocab:Sensor.
}
=>
{
_:request http:methodName "GET";
http:requestURI ?sensor;
http:resp [ http:body ?sensor ].
?sensor iot:name ?name;
iot:description ?desc;
vocab:madeObservation ?obs.
?obs vocab:hasTimestamp ?timestamp;
vocab:outputObservation ?result.
}.
The following ontologies are used to represent the semantic information in JSON-LD responses and RESTdesc descriptions: