gtran

Geospatial data I/O package making data conversion simple and manageable.

Installation

npm install gtran

Features

• Multi-format support - Just one package.

• Simple functions - Consistent functions for different formats, just from() and to().

• Promised - Powered by native Promise and it is happy working with your choice of promise library (Q, bluebird, and promise).

• GeoJson input/output - Get GeoJson from your file and save it into whatever you want.

Supported Formats

• CSV (point data only)

• KML

• KMZ (write only)

• Shapefile

• TopoJson (write only)

Functions

gtran provides two of functions: from[format name]() and to[format name]() for each support format.

• from[format name](fileName [, options])

  Read the geospatial data file and return a GeoJson object.

• to[format name](geojson, fileName [,options])

  Write the GeoJson object into a file with given name and format. If the file name is not given, the function returns a data object that could be written into file.

A full list of available functions:

• setPromiseLib(object)

  Specify the promise library. If not, the library will use the native Promise.

• .fromCSV(fileName, options)

  options:

  • projection - Geographic coordinate columns, necessary parameter. Please check the use example.

• .toCSV(geojson, fileName)

• .fromKml(fileName)

• .toKml(geojson, fileName, options)

  options:

  • name - Name property of feature.

  • symbol - Symbol of saved features. Detail about supported style options.

• .toKmz(geojson, fileName)

• .fromShp(fileName)

• .toShp(geojson, fileName, options)

  options:

  • esriWKT - ESRI WTK string that specifies the shapefile's spatial reference and generates .prj file. The ESRI WKT string could be found at SpatialReference.org.

• .toTopo(geojson)

Use Example

var gtran = require('gtran');
 
# Specify the promise library if necessary
gtran.setPromiseLib(require('bluebird'));
 
# Read shapefile
gtran.fromShp('source.shp')
.then(function(object) {
    var geojson = object;
});
 
# Save geojson into shapefile
gtran.toShp(geojson, 'point.shp')
.then(function(fileNames) {
    console.log('SHP files have been saved at:' + fileNames.toString());
});
 
# Read csv file
# If the test.csv has two columns: latitude and longitude
gtran.fromCSV('source.csv', {
    mapping: { x: 'longitude', y: 'latitude' }
})
.then(function(object) {
    var geojson = object;
});
 
# Save geojson into a csv file
gtran.toCSV(geojson, 'point.csv')
.then(function(fileName) {
    console.log('CSV file has been saved at:' + fileName);
});