domain

Documentation

Index

• Constants
• func MapRowsToFeatures(rows *sqlx.Rows, fidColumn string, externalFidColumn string, geomColumn string, ...) ([]*Feature, *PrevNextFID, error)
• type ContentCrs
  • func (c ContentCrs) IsWGS84() bool
  • func (c ContentCrs) ToLink() string
• type Cursors
  • func NewCursors(fid PrevNextFID, filtersChecksum []byte) Cursors
• type DecodedCursor
• type EncodedCursor
  • func (c EncodedCursor) Decode(filtersChecksum []byte) DecodedCursor
  • func (c EncodedCursor) String() string
• type Feature
• type FeatureCollection
• type JSONFGFeature
• type JSONFGFeatureCollection
• type Link
• type MapGeom
• type MapRelation
• type PrevNextFID
  • func MapRowsToFeatureIDs(rows *sqlx.Rows) (featureIDs []int64, prevNextID *PrevNextFID, err error)
• type Profile
  • func NewProfile(profileName ProfileName, baseURL url.URL, collectionNames []string) Profile
  • func (p *Profile) MapRelationUsingProfile(columnName string, columnValue any, externalFidColumn string) (newColumnName string, newColumnValue any)
• type ProfileName
• type SRID
  • func EpsgToSrid(srs string) (SRID, error)
  • func (s SRID) GetOrDefault() int

Constants

const (
	CrsURIPrefix  = "http://www.opengis.net/def/crs/"
	UndefinedSRID = 0
	WGS84SRID     = 100000 // We use the SRID for CRS84 (WGS84) as defined in the GeoPackage, instead of EPSG:4326 (due to axis order). In time, we may need to read this value dynamically from the GeoPackage.
	WGS84CodeOGC  = "CRS84"
	WGS84CrsURI   = CrsURIPrefix + "OGC/1.3/" + WGS84CodeOGC
)

const (
	ConformanceJSONFGCore = "http://www.opengis.net/spec/json-fg-1/0.2/conf/core"
)

Functions

func MapRowsToFeatures

func MapRowsToFeatures(rows *sqlx.Rows, fidColumn string, externalFidColumn string, geomColumn string,
	mapGeom MapGeom, mapRel MapRelation) ([]*Feature, *PrevNextFID, error)

MapRowsToFeatures datasource agnostic mapper from SQL rows/result set to Features domain model

Types

type ContentCrs

type ContentCrs string

ContentCrs the coordinate reference system (represented as a URI) of the content/output to return.

func (ContentCrs) IsWGS84

func (c ContentCrs) IsWGS84() bool

func (ContentCrs) ToLink

func (c ContentCrs) ToLink() string

ToLink returns link target conforming to RFC 8288

type Cursors

type Cursors struct {
	Prev EncodedCursor
	Next EncodedCursor

	HasPrev bool
	HasNext bool
}

Cursors holds next and previous cursor. Note that we use 'cursor-based pagination' as opposed to 'offset-based pagination'

func NewCursors

func NewCursors(fid PrevNextFID, filtersChecksum []byte) Cursors

NewCursors create Cursors based on the prev/next feature ids from the datasource and the provided filters (captured in a hash).

type DecodedCursor

type DecodedCursor struct {
	FiltersChecksum []byte
	FID             int64
}

DecodedCursor the cursor values after decoding EncodedCursor

type EncodedCursor

type EncodedCursor string

EncodedCursor is a scrambled string representation of the fields defined in DecodedCursor

func (EncodedCursor) Decode

func (c EncodedCursor) Decode(filtersChecksum []byte) DecodedCursor

Decode turns encoded cursor into DecodedCursor and verifies that the checksum of query params that act as filters hasn't changed

func (EncodedCursor) String

func (c EncodedCursor) String() string

type Feature

type Feature struct {
	geojson.Feature

	// we overwrite ID since we want to make it a required attribute. We also expect feature ids to be
	// auto-incrementing integers (which is the default in geopackages) since we use it for cursor-based pagination.
	ID    string `json:"id"`
	Links []Link `json:"links,omitempty"`
}

Feature is a GeoJSON Feature with extras such as links

type FeatureCollection

type FeatureCollection struct {
	Type      featureCollectionType `json:"type"`
	Timestamp string                `json:"timeStamp,omitempty"`
	Links     []Link                `json:"links,omitempty"`

	Features []*Feature `json:"features"`

	NumberReturned int `json:"numberReturned"`
}

FeatureCollection is a GeoJSON FeatureCollection with extras such as links

type JSONFGFeature

type JSONFGFeature struct {
	// We expect feature ids to be auto-incrementing integers (which is the default in geopackages)
	// since we use it for cursor-based pagination.
	ID   string      `json:"id"`
	Type featureType `json:"type"`
	Time any         `json:"time"`
	// we don't implement the JSON-FG "3D" conformance class. So Place only
	// supports simple/2D geometries, no 3D geometries like Polyhedron, Prism, etc.
	Place       geom.Geometry  `json:"place"`    // may only contain non-WGS84 geometries
	Geometry    geom.Geometry  `json:"geometry"` // may only contain WGS84 geometries
	Properties  map[string]any `json:"properties"`
	CoordRefSys string         `json:"coordRefSys,omitempty"`
	Links       []Link         `json:"links,omitempty"`
	ConformsTo  []string       `json:"conformsTo,omitempty"`
}

type JSONFGFeatureCollection

type JSONFGFeatureCollection struct {
	Type           featureCollectionType `json:"type"`
	Timestamp      string                `json:"timeStamp,omitempty"`
	CoordRefSys    string                `json:"coordRefSys"`
	Links          []Link                `json:"links,omitempty"`
	ConformsTo     []string              `json:"conformsTo"`
	Features       []*JSONFGFeature      `json:"features"`
	NumberReturned int                   `json:"numberReturned"`
}

type Link

type Link struct {
	Rel       string `json:"rel"`
	Title     string `json:"title,omitempty"`
	Type      string `json:"type,omitempty"`
	Href      string `json:"href"`
	Hreflang  string `json:"hreflang,omitempty"`
	Length    int64  `json:"length,omitempty"`
	Templated bool   `json:"templated,omitempty"`
}

Link according to RFC 8288, https://datatracker.ietf.org/doc/html/rfc8288

type MapGeom

type MapGeom func([]byte) (geom.Geometry, error)

MapGeom abstract function type to map geometry from bytes to Geometry

type MapRelation

type MapRelation func(columnName string, columnValue any, externalFidColumn string) (newColumnName string, newColumnValue any)

MapRelation abstract function type to map feature relations

type PrevNextFID

type PrevNextFID struct {
	Prev int64
	Next int64
}

PrevNextFID previous and next feature id (fid) to encode in cursor.

func MapRowsToFeatureIDs

func MapRowsToFeatureIDs(rows *sqlx.Rows) (featureIDs []int64, prevNextID *PrevNextFID, err error)

MapRowsToFeatureIDs datasource agnostic mapper from SQL rows set feature IDs, including prev/next feature ID

type Profile

type Profile struct {
	// contains filtered or unexported fields
}

Profile from OAF Part 5, used to express relations between features

func NewProfile

func NewProfile(profileName ProfileName, baseURL url.URL, collectionNames []string) Profile

func (*Profile) MapRelationUsingProfile

func (p *Profile) MapRelationUsingProfile(columnName string, columnValue any, externalFidColumn string) (newColumnName string, newColumnValue any)

type ProfileName

type ProfileName string

const (
	RelAsKey  ProfileName = "rel-as-key"  // RelAsKey a feature reference in the response SHALL be represented by: The featureId
	RelAsURI  ProfileName = "rel-as-uri"  // RelAsURI a feature reference in the response SHALL be represented by: an HTTP(S) URI.
	RelAsLink ProfileName = "rel-as-link" // RelAsLink a feature reference in the response SHALL be represented by: an object with the property "href" and, optionally a "title"
)

Profiles from OAF Part 5 as specified in https://docs.ogc.org/DRAFTS/23-058r1.html#rc_profile-parameter

type SRID

type SRID int

SRID Spatial Reference System Identifier: a unique value to unambiguously identify a spatial coordinate system. For example '28992' in https://www.opengis.net/def/crs/EPSG/0/28992

func EpsgToSrid

func EpsgToSrid(srs string) (SRID, error)

func (SRID) GetOrDefault

func (s SRID) GetOrDefault() int