Difference between revisions of "Location"

Revision as of 10:23, 26 April 2016

location supported property is represented using Well-known text (wkt) format

• Well-known text
• observations and things have a location property
  • this property can be used to define observer geo-spatial criteria (See Observers)
  • allows a geo-representation of the things

{
    ...
    "location": "{
                    \"sContext\" : \"geo\", 
                    \"wkt\" : \"POINT(-99.16297853 19.42359932)\"
                 }",
    ...
}

 Note: It is important to escape the quotation marks (") with \"

The value of this field consist on a stringified json object containing a mandatory field "wkt" defining the geometry, and two optional fields "sContext" (holding only "geo" as value to indicate that the wkt is written in geospatial context coordinates) and "hash" containing the geohash corresponding to the bounding rectangle of the given wkt. The field "hash" is computed internally so any value entered is ignored by the application.

The spatial location fields can be visually edited with the map or by writing the string in an input box

Edit by map

Edit by input box

In some cases, in particular when defining a spatial constraint in an observer, a location based field can be set by writing the whole string in an input. For instance, to define a rectangle it should be written

 {"wkt":"RECTANGLE(-100 19,-98 20)"}