worace / shp4s   0.2.1

Apache License 2.0 GitHub

Pure-Scala streaming Shapefile codec based on scodec and fs2

Scala versions: 2.13 2.12

shp4s - Pure Scala Shapefile Codec

Based on scodec and fs2.

Quick-Start

Installation

Published for Scala 2.12 and 2.13

libraryDependencies += "works.worace" %% "shp4s-core" % "0.2.1"

Basic Decoding

import works.worace.shp4s.Core
import works.worace.shp4s.Shape
import works.worace.shp4s.Feature
import works.worace.shp4s.DBFValue

val features: Vector[Feature] = Core.readAllSync("./path/to/file.shp")

val feature: Feature = features.head

// Shape geometry -- Point, PolyLine, etc
val shape: Shape = feature.shape

// Properties, from DBF file
val props: Map[String, DBFValue] = feature.properties

Streaming Usage (with fs2)

If you don't want to read the whole file into memory, you can decode it in streaming fashion using fs2

Note that you will need to use some cats-effect based tooling for this (fs2 streams resolve to an IO instance which needs to be evaluated).

import works.worace.shp4s.Core
import works.worace.shp4s.Shape
import works.worace.shp4s.Feature
import cats.effect.IO

val featureStream: fs2.Stream[IO, Feature] = Core.streamShapefile("./path/to/my.shp")

Converting Shapefile Features to JTS Geometries

import org.locationtech.jts.geom.Geometry
import works.worace.shp4s.Core
import works.worace.shp4s.Shape
import works.worace.shp4s.Feature
import works.worace.shp4s.DBFValue
import works.worace.shp4s.Jts
import works.worace.shp4s.JtsFeature

val features: Vector[Feature] = Core.readAllSync("./path/to/file.shp")

val feature: Feature = features.head

// Convert just the feature's geometry
val geom: Geometry = Jts.shapeToJts(feature.shape)

// Convert feature and pass through properties
val jtsFeat: JtsFeature = Jts.featureToJts(feature)
// JtsFeature(
//   geometry=Point (-118.13306035523306 33.85531587901563),
//   properties=Map(id -> DBFNumeric(1))
// )

Or you can use the provided implicit classes

import org.locationtech.jts.geom.Geometry
import works.worace.shp4s.Core
import works.worace.shp4s.Shape
import works.worace.shp4s.Feature
import works.worace.shp4s.DBFValue
import works.worace.shp4s.JtsFeature
import works.worace.shp4s.Jts.implicits._

val features: Vector[Feature] = Core.readAllSync("./path/to/file.shp")
val feature: Feature = features.head
feature.toJts() // JtsFeature(...)

Development

  • Run tests with sbt test
  • Push Scaladoc to GitHub Pages: sbt ghpagesPushSite
  • Run scalafmt: sbt scalafmtAll

Releasing

  • Set version in build.sbt to next non-SNAPSHOT
  • Make sure GPG and sonatype credentials are available -- ~/.sbt/sonatype_credentials, $PGP_PASSPHRASE, and appropriate key as specified in build.sbt
  • Run sbt +publishSigned
  • Open sonatype staging repository: https://oss.sonatype.org/#stagingRepositories and complete the release
    • Check contents (should have a 2.13 and 2.12 version for each module)
    • "close" the release, then "release" using sonatype UI options
  • Run git tag vX.Y.Z and push the tag
  • Set version to -SNAPSHOT for next version, commit, and push
  • Note: I think sbt-ci-release is better than doing this manually and i have used it previously on other projects but could not get it working this time for some reason :rip:

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Contributors

3 Dependencies

No Dependent