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Map::Leaflet

zef:bduggan

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NAME

Map::Leaflet - Generate maps using leaflet.js

SYNOPSIS

use Map::Leaflet;

my $map = Map::Leaflet.new;
$map.add-marker({ :lat(40.7128), :lon(-74.0060) }, "New York City");
$map.add-marker({ :lat(40.7589), :lon(-73.9851) }, "Empire State Building");
$map.add-marker( 40.7267, -73.9815, "Tompkins Square Park");

$map.add-geojson(q:to/GEOJSON/);
{
  "type": "Feature",
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [-74.0060, 40.7128],
      [-73.9851, 40.7589],
      [-73.9815, 40.7267],
      [-74.0060, 40.7128]
    ]
  }
}
GEOJSON

my $icon = $map.create-div-icon: html => "You are here";
$map.create-marker: latlng => [40.7128, -74.0060], options => %( icon => $icon );

$map.show;

output

DESCRIPTION

Generate HTML that renders a map, using the excellent leaflet.js library.

The Map::Leaflet class represents a map which can be rendered as HTML. Use a map object to create objects which are analogous to their javascript counterparts, and then render the entire page to generate the javascript.

There are default values for many of the leaflet objects, in an attempt to make common cases work more easily out of the box.

When creating layers, markers, icons, etc., methods named add-* are provided with convenient interfaces. For more control, use the create-* methods, which pass the options to the constructor for the corresponding object.

In other words, create-geojson-layer(...) is equivalent to add-layer(Map::Leaflet::GeoJSON.new(...)).

See the eg/ directory for more examples.

EXPORTS

If an argument is given when using the module, it is treated as the name of a new object to create. e.g.

use Map::Leaflet 'map';
map.add-marker(40.7128, -74.0060, "New York City");

is the same as

use Map::Leaflet 'map';
my \map = Map::Leaflet.new;
map.add-marker(40.7128, -74.0060, "New York City");

ATTRIBUTES

All of the attributes listed here https://leafletjs.com/reference.html#map-factory are available as attributes in the Map::Leaflet object. They will be passed to the javascript constructor. For callbacks, use a Pair object -- the key and value will be the left and right hand side of a javascript pointy block.

title

The title of the HTML page. Defaults to 'Map'.

center

A hash with lat and lon keys.

zoom

The zoom level (integer).

width, height

The height and width of the map. Defaults to 95vw and 95vh, respectively.

extra-css

Extra CSS to include in the HTML. The default adds a border, centers the map, and provides a class for div-icons.

tile-provider

The tile provider to use. Defaults to 'CartoDB.Positron'. For a complete list of providers, see https://leaflet-extras.github.io/leaflet-providers/preview/.

Here are a few of the providers listed: CartoDB.Positron, OpenStreetMap.Mapnik, Esri.WorldstreetMap

leaflet-version, leaflet-providers-version

The version of leaflet.js and leaflet-providers.js to use. Defaults to 1.9.4 and 1.13.0, respectively.

output-path

The filename to write the HTML to. Defaults to 'map-leaflet-tmp.html'.

other attributes

Other attributes that are passed on to the javascript constructor include: preferCanvas, attributionControl, zoomControl, closePopupOnClick, boxZoom, doubleClickZoom, dragging, zoomSnap, zoomDelta, trackResize, inertia, inertiaDeceleration, inertiaMaxSpeed, easeLinearity, worldCopyJump, maxBoundsViscosity, keyboard, keyboardPanDelta, scrollWheelZoom, wheelDebounceTime, wheelPxPerZoomLevel, tapHold, tapTolerance, touchZoom, bounceAtZoomLimits, crs, minZoom, maxZoom, maxBounds, renderer, zoomAnimation, zoomAnimationThreshold, fadeAnimation, markerZoomAnimation, transform3DLimit.

METHODS

new

my $map = Map::Leaflet.new;
my $map = Map::Leaflet.new(
    center => { :lat(40.7128), :lon(-74.0060) },
    zoom => 13
);

Constructor. If no center is specified, then bounds are computed, and the starting view will have a zoom level and extents that fit all of the layers that have been added. See ATTRIBUTES for more options.

add-marker

$map.add-marker({ :lat(40.7128), :lon(-74.0060) }, "New York City");
$map.add-marker( 40.7128, -74.0060, "New York City");

Add a marker. The first argument is a hash with lat and lon keys, and the second argument is an optional popup text. Or the first two arguments can be numeric for the lat + lon. See create-marker below for a more flexible way to create markers. Returns a Map::Leaflet::Marker object.

create-div-icon

my $div-icon = $map.create-div-icon(html => '<b>New York City</b>');
my $div-icon = $map.create-div-icon: html => '<b>Paris</b>', iconSize => 'auto', className => 'mlraku-div-icon';

Create a divIcon. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#divicon. Defaults to auto-sizing, a yellow background, and a black border, and a class of 'mlraku-div-icon'.

Also accepts a name option, which is used to name the icon in the javascript (defaults to an auto-generated name).

Returns a Map::Leaflet::DivIcon object.

create-icon

my $icon = $map.create-icon(iconUrl => 'https://leafletjs.com/examples/custom-icons/leaf-green.png');
my $icon = $map.create-icon: iconUrl => 'https://leafletjs.com/examples/custom-icons/leaf-green.png', iconSize => '[38, 95]';

Create an icon. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#icon. Note that the iconSize, iconAnchor, popupAnchor, and tooltipAnchor are all PointStr objects, which can be either a string of the form "[x, y]" or the string "auto".

create-marker

$map.create-marker(latlng => [ $lat, $lon ], options => %( icon => $icon ));
$map.create-marker: latlng => [ $lat, $lon ], options => %( title => 'New York City', popup-text => 'The Big Apple' );

Create a marker. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#marker. Also accepts popup-text as an option to generate a popup that is bound to the marker.

Defaults to False values for autoPan and autoPanFocus.

Returns a new Map::Leaflet::Marker.

add-geojson

$map.add-geojson($geojson, $style);
$map.add-geojson(q:to/GEOJSON/);
{
  "type": "Feature",
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [-74.0060, 40.7128],
      [-73.9851, 40.7589],
      [-73.9815, 40.7267],
      [-74.0060, 40.7128]
    ]
  }
}
GEOJSON
$map.add-geojson(
  %( :type<Feature>, :geometry(
    %( :type<LineString>, :coordinates(
      [
        [-74.0060, 40.7128],
        [-73.9851, 40.7589],
        [-73.9815, 40.7267],
        [-74.0060, 40.7128]
      ]
    ))
  )),
  style => { :color<red> }
);

Add a GeoJSON layer. $geojson can be a string or a hash. $style is optional and can also be a string or a hash.

add-circle, create-circle

my $circle = $map.create-circle(
    center => [40.7128, -74.0060],
    radius => 500, # meters
    color => 'red',
    fillColor => 'red',
    fillOpacity => 0.5,
);

$map.add-circle( 40.7128, -74.0060, 500, { color => 'red' } );

Create a circle. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#circle. Returns a new Map::Leaflet::Circle.

add-rectangle, create-rectangle

$map.add-rectangle(40.7128, -74.0060, 40.7589, -73.9851, color => 'red');
$map.add-rectangle([40.7128, -74.0060, 40.7589, -73.9851], color => 'red');

my $rectangle = $map.create-rectangle(
    bounds => [[40.7128, -74.0060], [40.7589, -73.9851]],
    color => 'red',
    fillColor => 'red',
    fillOpacity => 0.5,
);

Create a rectangle. The bounds can be specified either as four separate coordinates (lat1, lon1, lat2, lon2) or as an array of four numbers. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#rectangle. Returns a new Map::Leaflet::Rectangle.

add-polygon, create-polygon

my $polygon = $map.create-polygon(
    latlngs => [
        [40.7128, -74.0060],
        [40.7589, -73.9851],
        [40.7267, -73.9815]
    ],
    color => 'blue',
    fillColor => 'blue',
    fillOpacity => 0.3,
);

$map.add-polygon(latlngs => [[40.7128, -74.0060], [40.7589, -73.9851], [40.7267, -73.9815]]);

Create a polygon. The latlngs parameter is required and should be an array of coordinate pairs. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#polygon. Returns a new Map::Leaflet::Polygon.

add-polyline, create-polyline

my $polyline = $map.create-polyline(
    latlngs => [
        [40.7128, -74.0060],
        [40.7589, -73.9851]
    ],
    color => 'red',
    weight => 3,
);

$map.add-polyline(latlngs => [[40.7128, -74.0060], [40.7589, -73.9851]]);

Create a polyline. The latlngs parameter is required and should be an array of coordinate pairs. Accepts all of the leaflet.js options. See https://leafletjs.com/reference.html#polyline. Returns a new Map::Leaflet::Polyline.

add-icons, add-markers

These exist if you create icons or markers without using the create-* methods. They will add the objects to the map. For examples, see Map::Leaflet::Icon

render

spurt "map.html", $map.render;

Generate a complete HTML page for the map (including html, head, body, etc.). Returns a string.

show

$map.show;

Generate the HTML, write it to <$.output-path>, and open a browser to view it.

write

$map.write;

Generate the HTML and write it to <$.output-path>. Returns true if a new file was created, false if the file already existed and was overwritten.

SEE ALSO

https://leafletjs.com/

AUTHOR

Brian Duggan