arcpullr
arcpullr-package.Rd
A package for pulling spatial data from an ArcGIS REST API
Details
The role of the arcpullr package is simple...to pull spatial data from an ArcGIS REST API. These APIs are housed by various different agencies, organizations, entitites, etc., but allow a consistent format for storing and retrieving spatial data
get_spatial_layer
This function makes up the core of the package. It allows users to pull spatial data given a URL of an ArcGIS REST API. There are many additional query parameters that can (and probably should) be added; however, we've simplified many of these out for you with the functions below.
get_layer_by_spatial
family of functions
These functions allow you to pull layers using a spatial query. The abstract syntax is wrapped into the functions, so all you have to do is pass these functions an sf object of the spatial area, line, or point you want to query by. These functions include get_layer_by_poly, get_layer_by_point, get_layer_by_line, get_layer_by_multipoint, and get_layer_by_envelope. It should be fairly obvious what type of spatial layer each function takes with the exception of get_layer_by_envelope except that it isn't particularly useful for a single point.
get_image_layer
This is one of the core functions of the package. It retrieves image service layers from an ArcGIS REST API designated by the URL
get_map_layer
This is one of the core functions of the package. It retrieves map service layers from an ArcGIS REST API designated by the URL
Helper functions
There are a few utility functions to help you along the way. The first is
plot_layer
, which is a useful way to plot the spatial layer
you've tried to pull just to make sure it works. If you want fancier maps
you'd be better served with ggplot2 or tmaps, though.
Other helpers include the sf_objects
functions, which allow
you to easily create sf points, lines, and polygons with a few coordinates.
Lastly, there is a sql_where
function to help aid in building
more complex SQL WHERE clauses used to query by the where argument in the
retrieval functions above.