wavded/ogr2ogr

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ogr2ogr wraps the ogr2ogr GDAL tool to enable file conversion and re-projection of spatial data in simplified friendly API.

Installation

1. Install GDAL tools (includes the ogr2ogr command line tool)

2. Install package:

npm install ogr2ogr

Usage

ogr2ogr takes either a path, a stream, or a GeoJSON object. The result of the transformation will depend on the format returned.

// Using CommonJS modules
const ogr2ogr = require('ogr2ogr').default
// Using ECMAScript modules or Typescript
import ogr2ogr from 'ogr2ogr'

// Promise API
(async() {
  // Convert path to GeoJSON.
  let {data} = await ogr2ogr('/path/to/spatial/file')
  console.log(data)

  // Convert GeoJSON object to ESRI Shapefile stream.
  let {stream} = await ogr2ogr(data, {format: 'ESRI Shapefile'})

  // Convert ESRI Shapefile stream to KML text.
  let {text} = await ogr2ogr(stream, {format: 'KML'})
  console.log(text)
})()

// Callback API
ogr2ogr('/path/to/spatial/file').exec((err, {data}) => {
  console.log(data)
})

Formats

ogr2ogr has varying support for format input and output. Consult the particular driver you are interested in for more details. It is highly recommend to run the latest version of GDAL to get the best support. This project attempts to cast the widest net for support. Here are some notables:

API

ogr2ogr(input, options?) -> Promise<output>

The input may be one of:

• A path (string). This includes file paths and network paths including HTTP endpoints.
• A ReadableStream.
• A GeoJSON object.

The following options are available (none required):

• format - Output format (default: GeoJSON)
• timeout - Timeout, in milliseconds, before command forcibly terminated (default: 0)
• maxBuffer - Max output size in bytes for stdout/stderr (default: 1024 * 1024 * 50)
• options - Custom ogr2ogr arguments and driver options (e.g. ['--config', 'SHAPE_RESTORE_SHX', 'TRUE'])
• env - Custom environmental variables (e.g. {ATTRIBUTES_SKIP: 'YES'})
• destination - Select another output than the output object (e.g. useful for writing to databases).
• command - Command to run (default: ogr2ogr)

The output object has the following properties:

• cmd - The ogr2ogr command executed (useful for debugging).
• text - Text output from drivers that support /vsistdout/ (see formats above)
• data - Parsed GeoJSON output (used when format is GeoJSON)
• stream - A ReadableStream of the output. Used for drivers that do not support /vsistdout/.
  • If a driver generates more than one file (like ESRI Shapefile), this will be a zip stream containing all the data.
• extname - The file extension of the data returned.
• details - Any text printed to STDERR. This includes any warnings reported by ogr2ogr when it ran.

ogr2ogr(input, options?).exec((err, output))

The callback API supports the same options as above but in a NodeJS style callback format.

Tips and tricks

Running ogr2ogr in a Docker container:

ogr2ogr("/home/.../path/to/spatial/file", {
  command: "docker run -v /home/:/home --rm osgeo/gdal ogr2ogr",
})

Converting an isolated .shp file:

ogr2ogr("/path/to/file.shp", {
  options: ["--config", "SHAPE_RESTORE_SHX", "TRUE"],
})

Getting more debug information by using the CPL_DEBUG option. Debug info added to details on the output object.

ogr2ogr("/path/to/file.shp", {
  options: ["--config", "CPL_DEBUG", "TRUE"],
})

Parsing custom geometry fields in a CSV. Use CSV driver options, like:

ogr2ogr("/path/to/file.csv", {
  options: ["-oo", "GEOM_POSSIBLE_NAMES=the_geom"],
})

Re-project geometry:

ogr2ogr("/path/to/file.shp", {
  options: ["-t_srs", "EPSG:4326"],
})