Quickstart Guide

To start using the leaflet-rails gem, follow the steps below (assuming you use the default asset pipeline):

First, add the following code to your Gemfile.

gem 'leaflet-rails'

Then, run bundle install from within your project to download the necessary files. Following that, open your application-wide CSS file (app/assets/stylesheets/application.css) and add the following line as a comment:

= require leaflet

After that, open your application-wide Javascript file (typically app/assets/javascripts/application.js) and add the following line before requiring files which depend on Leaflet:

= require leaflet

At this point, you may skip the first two steps of the Leaflet Quick Start guide and start at the third step (adding the map div to a view).

Helpers

To get you up and running quickly, you can also use the gem's helper. To get started, add the following lines to a file called leaflet.rb in config/initializers:

Leaflet.tile_layer = "http://{s}.tile.cloudmade.com/YOUR-CLOUDMADE-API-KEY/997/256/{z}/{x}/{y}.png"
# You can also use any other tile layer here if you don't want to use Cloudmade - see http://leafletjs.com/reference.html#tilelayer for more
Leaflet.attribution = "Your attribution statement"
Leaflet.max_zoom = 18

You will then be able to call the helper in a view like so:

map(:center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
})

You can also add any number of markers like so:

map(:center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
  },
  :markers => [
    {
       :latlng => [51.52238797921441, -0.08366235665359283],
    }
  ]
)

Adding a :popup element to a marker hash will also generate a popup for a maker:

map(:center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
  },
  :markers => [
     {
       :latlng => [51.52238797921441, -0.08366235665359283],
       :popup => "Hello!"
     }
  ]
)

If you want to override the map settings you have set in the initializer, you can also add them to the helper:

map(:center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
  },
  :tile_layer => "http://{s}.somedomain.com/somepath/{z}/{x}/{y}.png",
  :attribution => "Some other attribution text",
  :max_zoom => 4
)

If you want to have multiple maps on same page , you should add unique container_id in helper for each map:

map(:container_id => "first_map", :center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
})

map(:container_id => "second_map", :center => {
    :latlng => [51.52238797921441, -0.08366235665359283],
    :zoom => 18
})