hierarchy

README

go-whosonfirst-spatial-hierarchy

Opionated Who's On First (WOF) hierarchy for go-whosonfirst-spatial packages.

Documentation

Documentation is incomplete.

Example

import (
	_ "github.com/whosonfirst/go-whosonfirst-spatial-sqlite"
)

import (
	"github.com/whosonfirst/go-whosonfirst-spatial-hierarchy"
	hierarchy_filter "github.com/whosonfirst/go-whosonfirst-spatial-hierarchy/filter"		
	"github.com/whosonfirst/go-whosonfirst-spatial/database"
	spatial_filter "github.com/whosonfirst/go-whosonfirst-spatial/filter"
)

body := []byte(`{"type":"Feature" ...}`)

spatial_db, _ := database.NewSpatialDatabase(ctx, "sqlite://?dsn=/usr/local/data/whosonfirst.db")

resolver_opts := &hierarchy.PointInPolygonHierarchyResolverOptions{
	Database: spatial_db,
}

resolver, _ := hierarchy.NewPointInPolygonHierarchyResolver(ctx, resolver_opts)

inputs := &spatial_filter.SPRInputs{}

results_cb := hierarchy_filter.FirstButForgivingSPRResultsFunc
update_cb := hierarchy.DefaultPointInPolygonHierarchyResolverUpdateCallback()
		
new_body, _ := resolver.PointInPolygonAndUpdate(ctx, inputs, results_cb, update_cb, body)

See also

• https://github.com/whosonfirst/go-whosonfirst-spatial
• https://github.com/whosonfirst/go-whosonfirst-spatial-pip
• https://github.com/whosonfirst/go-whosonfirst-exporter
• https://github.com/sfomuseum/go-sfomuseum-mapshaper

Documentation

Overview

package hierarchy provides methods for deriving hierarchies from and associated with Who's On First records.

Index

• type PointInPolygonHierarchyResolver
  • func NewPointInPolygonHierarchyResolver(ctx context.Context, opts *PointInPolygonHierarchyResolverOptions) (*PointInPolygonHierarchyResolver, error)
  • func (t *PointInPolygonHierarchyResolver) PointInPolygon(ctx context.Context, inputs *filter.SPRInputs, body []byte) ([]spr.StandardPlacesResult, error)
  • func (t *PointInPolygonHierarchyResolver) PointInPolygonAndUpdate(ctx context.Context, inputs *filter.SPRInputs, ...) (bool, []byte, error)
  • func (t *PointInPolygonHierarchyResolver) PointInPolygonCentroid(ctx context.Context, body []byte) (*orb.Point, error)
  • func (t *PointInPolygonHierarchyResolver) SetReader(r reader.Reader)
• type PointInPolygonHierarchyResolverOptions
• type PointInPolygonHierarchyResolverUpdateCallback
  • func DefaultPointInPolygonHierarchyResolverUpdateCallback() PointInPolygonHierarchyResolverUpdateCallback

Types

type PointInPolygonHierarchyResolver

type PointInPolygonHierarchyResolver struct {
	// Database is the `database.SpatialDatabase` instance used to perform point-in-polygon requests.
	Database database.SpatialDatabase
	// Mapshaper is an optional `mapshaper.Client` instance used to derive centroids used in point-in-polygon requests.
	Mapshaper *mapshaper.Client
	// PlacetypesDefinition is an optional `go-whosonfirst-placetypes.Definition` instance used to resolve custom or bespoke placetypes.
	PlacetypesDefinition placetypes.Definition
	// Logger is a `log.Logger` instance for logging feedback. The default logger sends all messages to `io.Discard`.
	Logger *log.Logger
	// contains filtered or unexported fields
}

PointInPolygonHierarchyResolver provides methods for constructing a hierarchy of ancestors for a given point, following rules established by the Who's On First project.

func NewPointInPolygonHierarchyResolver

func NewPointInPolygonHierarchyResolver(ctx context.Context, opts *PointInPolygonHierarchyResolverOptions) (*PointInPolygonHierarchyResolver, error)

NewPointInPolygonHierarchyResolver returns a `PointInPolygonHierarchyResolver` instance for 'spatial_db' and 'ms_client'. The former is used to perform point in polygon operations and the latter is used to determine a "reverse geocoding" centroid to use for point-in-polygon operations.

func (*PointInPolygonHierarchyResolver) PointInPolygon

func (t *PointInPolygonHierarchyResolver) PointInPolygon(ctx context.Context, inputs *filter.SPRInputs, body []byte) ([]spr.StandardPlacesResult, error)

PointInPolygon will perform a point-in-polygon (reverse geocoding) operation for 'body' using zero or more 'inputs' as query filters. This is known to not work as expected if the `wof:placetype` property is "common". There needs to be a way to a) retrieve placetypes using a custom WOFPlacetypeSpecification (go-whosonfirst-placetypes v0.6.0+) and b) specify an alternate property to retrieve placetypes from if `wof:placetype=custom`.

func (*PointInPolygonHierarchyResolver) PointInPolygonAndUpdate

func (t *PointInPolygonHierarchyResolver) PointInPolygonAndUpdate(ctx context.Context, inputs *filter.SPRInputs, results_cb hierarchy_filter.FilterSPRResultsFunc, update_cb PointInPolygonHierarchyResolverUpdateCallback, body []byte) (bool, []byte, error)

PointInPolygonAndUpdate will ...

func (*PointInPolygonHierarchyResolver) PointInPolygonCentroid

func (t *PointInPolygonHierarchyResolver) PointInPolygonCentroid(ctx context.Context, body []byte) (*orb.Point, error)

PointInPolygonCentroid derives an *orb.Point (or "centroid") to use for point-in-polygon operations.

func (*PointInPolygonHierarchyResolver) SetReader

func (t *PointInPolygonHierarchyResolver) SetReader(r reader.Reader)

SetReader assigns 'r' as the internal `reader.Reader` instance used to retrieve ancestor records when resolving a hierarchy.

type PointInPolygonHierarchyResolverOptions

type PointInPolygonHierarchyResolverOptions struct {
	// Database is the `database.SpatialDatabase` instance used to perform point-in-polygon requests.
	Database database.SpatialDatabase
	// Mapshaper is an optional `mapshaper.Client` instance used to derive centroids used in point-in-polygon requests.
	Mapshaper *mapshaper.Client
	// PlacetypesDefinition is an optional `go-whosonfirst-placetypes.Definition` instance used to resolve custom or bespoke placetypes.
	PlacetypesDefinition placetypes.Definition
	// Logger is an optional `log.Logger` instance for logging feedback.
	Logger *log.Logger
	// SkipPlacetypeFilter is an optional boolean flag to signal whether or not point-in-polygon operations should be performed using
	// the list of known ancestors for a given placetype. Default is false.
	SkipPlacetypeFilter bool
	// Roles is an optional list of Who's On First placetype roles used to derive ancestors during point-in-polygon operations.
	// If missing (or zero length) then all possible roles will be assumed.
	Roles []string
}

type PointInPolygonHierarchyResolverUpdateCallback

type PointInPolygonHierarchyResolverUpdateCallback func(context.Context, reader.Reader, spr.StandardPlacesResult) (map[string]interface{}, error)

PointInPolygonHierarchyResolverUpdateCallback is a function definition for a custom callback to convert 'spr' in to a dictionary of properties containining hierarchy information. Records in 'spr' are expected to be able to be read from 'r'.

func DefaultPointInPolygonHierarchyResolverUpdateCallback

func DefaultPointInPolygonHierarchyResolverUpdateCallback() PointInPolygonHierarchyResolverUpdateCallback

DefaultPointInPolygonHierarchyResolverUpdateCallback returns a `PointInPolygonHierarchyResolverUpdateCallback` function that will return a dictionary containing the following properties: wof:parent_id, wof:country, wof:hierarchy