Dxf-polygon-importer NPM

DXF Polygon Importer

Parses a DXF file and imports closed 'CAD Polylines' as polygons and labels as points into a PostGIS table. The imports will be versioned based on a project identifier and filename combination.

Installation and requirements

npm install dxf-polygon-importer

The module requires ogr2ogr and a PostGIS enabled PostgreSQL database connection.

Following environment variables need to be set:

DXF_TOOLS_DB_HOST      ...  PostgreSQL server host
DXF_TOOLS_DB_USER      ...  Database user name
DXF_TOOLS_DB_PASSWORD  ...  Database user password
DXF_TOOLS_DB_NAME      ...  Database name

The module creates following database tables and views:

dxf_features [table]   ...  all imported geometries
all_polygons [view]    ...  last version of imported polygons
all_labels   [view]    ...  last version of imported label points

Usage

var Importer = require('dxf-polygon-importer');

Importer('mydrawing.dxf', {
  polygonLayer: 'MYPOLYLINES',
  labelLayer: 'MYNAMES',
  project: 'MyProject'
}).go().then(function (data) {
  // handle data
  // { filename: 'mydrawing.dxf', project: 'MyProject', version: 1 }
});

API

initialize `Importer(file, options)`

The class takes a DXF file path as first file argument and options object with following properties as second:

{
  polygonLayer: String,  ...  CAD layer containing polygons
  labelLayer: String,    ...  CAD layer containing labels
  project: String        ...  Unique project identifier
}

go `Importer.go(keepPool)`

Initiates the import process with schema-setup, polyline-conversions and sql-inserts. The method takes a keepPool Boolean argument to indicate if database connection pool should be kept alive or torn down after import. This can be useful if the pool should be used for multiple subsequent imports. Default value is falsy, 'undefined'.