Node Mapnik

add_layer(new)

Add a new layer to this map

Parameters

clear

Remove all layers and styles from this map

clone

Clone this map object, returning a value which can be changed without mutating the original

Returns

font

Get all of the fonts currently registered as part of this map

fontDirectory

Get the currently-registered font directory, if any

Returns

fontFiles

Get all of the fonts currently registered as part of this map, as a mapping from font to font file

Returns

fromStringSync(stylesheet, [options], callback)

Load styles, layers, and other information for this map from a Mapnik XML stylesheet given as a string.

Parameters

Example

var fs = require('fs');
map.fromStringSync(fs.readFileSync('./style.xml', 'utf8'), function(err, res) {
  // details loaded
});

fromStringSync(stylesheet, [options])

Load styles, layers, and other information for this map from a Mapnik XML stylesheet given as a string.

Parameters

Example

var fs = require('fs');
map.fromStringSync(fs.readFileSync('./style.xml', 'utf8'));

get_layer(layer)

Get a layer out of this map, given a name or index

Parameters

Returns

Throws

• Error :

  if index is incorrect or layer is not found

layers

Get all of the currently-added layers in this map

load(stylesheet, [options], callback)

Load styles, layers, and other information for this map from a Mapnik XML stylesheet.

Parameters

loadSync(stylesheet, [options])

Load styles, layers, and other information for this map from a Mapnik XML stylesheet.

Parameters

Example

map.loadSync('./style.xml');

resize(width, height)

Give this map new dimensions

Parameters

scale

Get the map's scale factor. This is the ratio between pixels and geographical units like meters.

Returns

scaleDenominator

Get the map's scale denominator.

Returns

addData(raw, name)

Add raw data to this tile as a Buffer

Parameters

addGeoJSON(geojson, name)

Add features to this tile from a GeoJSON string

Parameters

clear(callback)

Remove all data from this vector tile

Parameters

compositeSync

Composite an array of vector tiles into one vector tile

empty(whether)

Return whether this vector tile is empty - whether it has no layers and no features

Parameters

getData(map, renderable, callback)

Render this vector tile to a surface, like a mapnik.Image

Parameters

getDataSync

Get the data in this vector tile as a buffer

Returns

height(height)

Get the vector tile's height

Parameters

isSolid(callback)

Test whether this tile is solid - whether it has features

Parameters

isSolidSync

Test whether this tile is solid - whether it has features

Returns

names

Get the names of all of the layers in this vector tile

painted(painted)

Get whether the vector tile has been painted

Parameters

query(longitude, latitude, [options], callback)

Query a vector tile by longitude and latitude

Parameters

reportGeometrySimplicity(callback)

Count the number of non OGC simple geometries

Parameters

reportGeometrySimplicitySync

Count the number of geometries that are not OGC simple

Returns

reportGeometryValidity(callback)

Count the number of non OGC valid geometries

Parameters

reportGeometryValiditySync

Count the number of geometries that are not OGC valid

Returns

setData(raw, name)

Replace the data in this vector tile with new raw data

Parameters

toGeoJSON(callback)

Get a GeoJSON representation of this tile

Parameters

Returns

toGeoJSONSync

Get a GeoJSON representation of this tile

Returns

toJSON

Get a JSON representation of this tile

Returns

width(width)

Get the vector tile's width

Parameters

addField(field)

Add a field to this grid's output

Parameters

addField

Get all of this grid's fields

encodeSync([options])

Get a constrained view of this field given x, y, width, height parameters.

Parameters

Returns

height

Get this grid's height

Returns

view(x, y, width, height)

Get a constrained view of this field given x, y, width, height parameters.

Parameters

Returns

width

Get this grid's width

Returns

attributes

Get the feature's attributes as an object.

Returns

extent

Get the feature's extent

geometry

Get the feature's attributes as a Mapnik geometry.

Returns

id

Returns

toJSON

Generate and return a GeoJSON representation of this feature

Returns

fromJSON(geojson)

Parameters

clear(callback)

Make this image transparent, removing all image data from it.

Parameters

clearSync

Make this image transparent.

Example

var im = new mapnik.Image(5,5);
im.fillSync(1);
assert.equal(im.getPixel(0, 0), 1);
im.clearSync();
assert.equal(im.getPixel(0, 0), 0);

compare(other, [options])

Compare two images visually. This is useful for algorithms and tests that confirm whether a certain image has changed significantly.

Parameters

Returns

composite(other, callback)

Overlay this image with another image, creating a layered composite as a new image

Parameters

copy(type, [options], callback)

Copy this image data so that changes can be made to a clone of it.

Parameters

copySync(type, [options])

Copy this image data so that changes can be made to a clone of it.

Parameters

Returns

data

Return a copy of the pixel data in this image as a buffer

demultiply(callback)

Demultiply the pixels in this image, asynchronously. The opposite of premultiplying

Parameters

demultiplySync

Demultiply the pixels in this image. The opposite of premultiplying

encode([format], callback)

Encode this image into a buffer of encoded data

Parameters

Returns

Example

var fs = require('fs');
myImage.encode('png', function(err, encoded) {
  fs.writeFileSync('myimage.png', encoded);
});

encodeSync([format])

Encode this image into a buffer of encoded data

Parameters

Returns

Example

var fs = require('fs');
fs.writeFileSync('myimage.png', myImage.encodeSync('png'));

fill(color, callback)

Asynchronously fill this image with a given color.

Parameters

Example

var im = new mapnik.Image(5, 5);
im.fill(1, function(err, im_res) {
  if (err) throw err;
  assert.equal(im_res.getPixel(0, 0), 1);
});

fillSync(color)

Fill this image with a given color

Parameters

filter(filter, callback)

Asynchronously filter this image.

Parameters

Example

var im = new mapnik.Image(5, 5);
im.filter("blur", function(err, im_res) {
  if (err) throw err;
  assert.equal(im_res.getPixel(0, 0), 1);
});

filterSync(filter)

Filter this image

Parameters

getPixel(x, y, options)

Parameters

Returns

Example

var im = new mapnik.Image(256, 256);
var view = im.view(0, 0, 256, 256);
var pixel = view.getPixel(0, 0, {get_color:true});
assert.equal(pixel.r, 0);
assert.equal(pixel.g, 0);
assert.equal(pixel.b, 0);
assert.equal(pixel.a, 0);

getType

Determine the image type

Returns

height

Get this image's height

Returns

isSolidSync

Determine whether the image is solid - whether it has alpha values of greater than one.

Returns

Example

var im = new mapnik.Image(256, 256);
var view = im.view(0, 0, 256, 256);
assert.equal(view.isSolidSync(), true);

premultiplied

Determine whether the given image is premultiplied.

Returns

premultiply(callback)

Premultiply the pixels in this image, asynchronously

Parameters

premultiplySync

Premultiply the pixels in this image

resize(width, height, [options], callback)

Create a copy this image that is resized

Parameters

resizeSync(width, height, [options])

Make a resized copy of an image

Parameters

Returns

save(filename, [format], callback)

Encode this image and save it to disk as a file.

Parameters

saveSync(filename, [format])

Encode this image and save it to disk as a file.

Parameters

Example

myImage.saveSync('foo.png');

setPixel(x, y, numeric)

Parameters

view(x, y, width, height)

Get a constrained view of this image given x, y, width, height parameters.

Parameters

Returns

width

Get this image's width

Returns

fromBufferSync(width, height, buffer)

Create an image of the existing buffer. BUFFER MUST LIVE AS LONG AS THE IMAGE. It is recommended that you do not use this method! Be warned!

Parameters

Returns

fromBytes(buffer, callback)

Create a new image from a buffer

Parameters

fromSVG(filename, callback)

Create a new image from an SVG file

Parameters

fromSVGBytes(filename, callback)

Create a new image from an SVG file

Parameters

describe

Describe the datasource's contents and type.

Returns

extent

Get the Datasource's extent

extent

Get the geometry's extent

toJSON([options], callback)

Convert this geometry into a GeoJSON representation, asynchronously.

Parameters

toJSONSync

Convert this geometry into a GeoJSON representation, synchronously.

Returns

toWKB

Get the geometry's representation as Well-Known Binary

Returns

toWKT

Get the geometry's representation as Well-Known Text

Returns

type

Get the geometry type

Returns

forward

Project from a position in WGS84 space to a position in this projection.

Example

var merc = new mapnik.Projection('+init=epsg:3857');
var long_lat_coords = [-122.33517, 47.63752];
var projected = merc.forward(long_lat_coords);

inverse

Unproject from a position in this projection to the same position in WGS84 space.

get_premultiplied

Get whether this color is premultiplied

Returns

hex

Get this color represented as a hexademical string

Returns

Example

var c = new mapnik.Color('green');
c.hex();
// '#008000'

set_premultiplied(premultiplied)

Set whether this color should be premultiplied

Parameters

Throws

• TypeError :

  given a non-boolean argument

Example

var c = new mapnik.Color('green');
c.set_premultiplied(true);

toString

Get this color's representation as a string

Returns

Example

var green = new mapnik.Color('green');
green.toString()
// 'rgb(0,128,0)'

next

Return the next Feature in this featureset if it exists, or null if it does not.

Returns

mapnik

Mapnik is the core of cartographic design and processing.

Properties

Example

var mapnik = require('node-mapnik');

Static members

mapnik.blend(options, callback)

Composite multiple images on top of each other, with strong control over how the images are combined, resampled, and blended.

Parameters

Example

mapnik.blend([
 fs.readFileSync('foo.png'),
 fs.readFileSync('bar.png'),
], function(err, result) {
 if (err) throw err;
 fs.writeFileSync('result.png', result);
});

mapnik.Color(value, green, blue, blue, premultiplied)

Parameters

Throws

• TypeError :

  if a rgb component is outside of the 0-255 range

Example

var c = new mapnik.Color('green');
var c = new mapnik.Color(0, 128, 0, 255);
// premultiplied
var c = new mapnik.Color(0, 128, 0, 255, true);

mapnik.Datasource

A Datasource object. This is the connector from Mapnik to any kind of file, network, or database source of geographical data.

mapnik.Feature

A single geographic feature, with geometry and properties. This is typically derived from data by a datasource, but can be manually created.

mapnik.Featureset

An iterator of mapnik.Feature objects.

mapnik.Geometry

Geometry: a representation of geographical features in terms of shape alone. This class provides many useful functions for conversion to and from formats.

You'll never create a mapnik.Geometry instance manually: it is always part of a mapnik.Feature instance, which is often a part of a mapnik.Featureset instance.

mapnik.Grid(width, height, [options])

Generator for UTFGrid representations of data.

Parameters

Properties

mapnik.Image(width, height, options)

Parameters

Throws

• TypeError :

  if any argument is the wrong type, like if width or height is not numeric.

Example

var im = new mapnik.Image(256, 256, {
  premultiplied: true,
  type: mapnik.imageType.gray8
});

mapnik.ImageView(left, top, width, height)

This is usually not initialized directly: you'll use the mapnik.Image#view method to instantiate an instance.

Parameters

Throws

• TypeError :

  if any argument is missing or not numeric

Example

var im = new mapnik.Image(256, 256);
var view = im.view(0, 0, 256, 256);

mapnik.Map(width, width, projection)

A map in mapnik is an object that combined data sources and styles in a way that lets you produce styled cartographic output.

Parameters

Example

var map = new mapnik.Map(25, 25, '+init=epsg:3857');

mapnik.Projection(projection, [options])

A geographical projection: this class makes it possible to translate between locations in different projections

Parameters

Throws

• TypeError :

  if the projection string or options argument is the wrong type

• Error :

  the projection could not be initialized - it was not found in proj4's tables or the string was malformed

Example

var wgs84 = new mapnik.Projection('+init=epsg:4326');

mapnik.VectorTile(z, x, y)

A generator for the Mapbox Vector Tile specification of compressed and simplified tiled vector data

Parameters

Example

var vtile = new mapnik.VectorTile(9,112,195);