Prepare JSON for use as a spatial filter based on feature geometry or bounding box input

prepare_spatial_filter() prepares a named list with ESRI JSON geometry for use as a spatial filter based on a a sfc, sfg, or bbox input object.

match_spatial_rel() takes a scalar character vector with a predicate name to a type of ESRI spatial relation.

Usage

prepare_spatial_filter(
  filter_geom,
  crs,
  predicate,
  error_call = rlang::caller_env()
)

match_spatial_rel(predicate, error_call = rlang::caller_env())

Arguments

filter_geom: an object of class bbox, sfc or sfg used to filter query results based on a predicate function.
crs: a representation of a coordinate reference system.
predicate: Spatial predicate to use with filter_geom. Default "intersects". Possible options are "intersects", "contains", "crosses", "overlaps", "touches", and "within".
error_call: default rlang::caller_env().

Value

prepare_spatial_filter() returns a named list with the geometryType, geometry (as Esri JSON), and spatial relation predicate.

match_spatial_rel() returns one of the following spatial binary predicates:

esriSpatialRelIntersects
esriSpatialRelContains
esriSpatialRelCrosses
esriSpatialRelOverlaps
esriSpatialRelTouches
esriSpatialRelWithin

Details

Using sfc objects as filter_geom

If an sfc object is provided it will be transformed to the layers spatial reference. If the sfc is missing a CRS (or is an sfg object) it is assumed to use the same spatial reference as the FeatureLayer. If the sfc object has multiple features, the features are unioned with sf::st_union(). If an sfc object has MULTIPOLYGON geometry, the features are unioned before being cast to POLYGON geometry with sf::st_cast(). All geometries are checked for validity before conversion.

Examples

prepare_spatial_filter(sf::st_point(c(0, 5)), 4326, "intersects")
#> $geometryType
#> [1] "esriGeometryPoint"
#> 
#> $geometry
#> [1] "{\"x\":0.0,\"y\":5.0,\"spatialReference\":{\"wkid\":4326}}"
#> 
#> $spatialRel
#> [1] "esriSpatialRelIntersects"
#>