3.2 Search for resources

3.2.1 Searching by configurable query

To search for resource we need to create a query to the symbIoTe Core. In our example we use https://symbiote-open.man.poznan.pl/coreInterface/query endpoint and provide parameters for querying. Requests need properly generated security headers. More on topic of secure access to symbIoTe component can be read on SymbIoTeSecurity project page https://github.com/symbiote-h2020/SymbIoTeSecurity.

All possible query parameters can be seen below:

Query parameters {
         platform_id:           String
         platform_name:         String
         owner:                 String
         name:                  String
         id:                    String
         description:           String
         location_name:         String
         location_lat:          Double
         location_long:         Double
         max_distance:          Integer
         observed_property:     List<String>
         resource_type: 	String
         should_rank:           Boolean
}

NOTE1
To query using geospatial properties, all 3 properties need to be set: location_lat (latitude), location_long (longitude) and max_distance (distance from specified point in meters).

NOTE2
Text parameters allow substring searches using '*' character which can be placed at the beginning and/or end of the word to search for. For example querying for name "Sensor*" finds all resources with name starting with Sensor, and search for name "*12*" will find all resources containing string "12" in its name. Using substring search can be done for the following fields:

• name
• platform_name
• owner
• description
• location_name
• observed_property

NOTE3
The should_rank parameter can be set to enable ranking of the resources from the response. This allows currently available and popular resources to be returned with higher ranking than others. Also, if geolocation point is used in the query resources closer to the point of interest are returned with higher ranking.

For our example, let's search for resources with name Stationary 1. We do it by sending a HTTP GET request on symbIoTe Core Interface (https://symbiote-open.man.poznan.pl/coreInterface/query?name=Stationary1). Response contains a list of resources fulfilling the criteria:

{
  "resources": [
    {
      "platformId": "test1Plat",
      "platformName": "Test 1 Plat",
      "owner": null,
      "name": "Stationary1",   
      "id": "591ae23eb80b283c012fdf26",
      "description": "This is stationary 1",
      "locationName": "SomeLocation",
      "locationLatitude": 25.864716,
      "locationLongitude": 5.349014,
      "locationAltitude": 35,
      "observedProperties": [
        "temperature",
        "humidity"
      ],
      "resourceType": [
        "http://www.symbiote-h2020.eu/ontology/core#StationarySensor"
      ],
      "ranking": 0.2
     }
  ]
}

3.2.2 SPARQL query endpoint

Starting with Release 0.2.1, an additional endpoint was created to allow sending SPARQL queries to symbIoTe Core. To send SPARQL requests we need to send request by using HTTP POST to the url:
https://symbiote-open.man.poznan.pl/coreInterface/sparqlQuery

The endpoint accepts the following payload:

{ 
    "sparqlQuery" : "<sparql>",
    "outputFormat" : "<format>"
    
}

Possible output formats include: SRX, XML, JSON, SRJ, SRT, THRIFT, SSE, CSV, TSV, SRB, TEXT, COUNT, TUPLES, NONE, RDF, RDF_N3, RDF_XML, N3, TTL, TURTLE, GRAPH, NT, N_TRIPLES, TRIG.

SPARQL allows for powerful access to all the meta information stored within symbIoTe Core. Below, you can find few example queries

Query all resources of the core

{
    "sparqlQuery" : "PREFIX cim: <http://www.symbiote-h2020.eu/ontology/core#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT ?res ?resourceName WHERE { ?res a cim:Resource. ?res rdfs:label ?resourceName . }",
    "outputFormat" : "TEXT"
}

returns the following output:

------------------------------------------------------------------------------------------------------
| res                                                                        | resourceName          |
======================================================================================================
| <http://www.symbiote-h2020.eu/ontology/resources/591ae23eb80b283c012fdf26> | "Stationary 1"        |
| <http://www.symbiote-h2020.eu/ontology/resources/591ae5edb80b283c012fdf29> | "Actuating Service 1" |
------------------------------------------------------------------------------------------------------

Query for Services and display information about input they are requiring: name and datatype

{
    "sparqlQuery" : "PREFIX cim: <http://www.symbiote-h2020.eu/ontology/core#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT ?res ?resourceName ?inputName ?inputDatatype WHERE { ?res a cim:Service. ?res rdfs:label ?resourceName . ?res cim:hasInputParameter ?input . ?input cim:name ?inputName . ?input cim:datatype ?inputDatatype }",
    "outputFormat" : "TEXT"
}

returns the following output:

--------------------------------------------------------------------------------------------------------------------------------------
| res                                                                        | resourceName          | inputName     | inputDatatype |
======================================================================================================================================
| <http://www.symbiote-h2020.eu/ontology/resources/591af131b80b2847be1d62eb> | "Actuating Service 1" | "inputParam1" | "xsd:string"  |
--------------------------------------------------------------------------------------------------------------------------------------